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ACS Bio & Med Chem Au

● American Chemical Society (ACS)

Preprints posted in the last 30 days, ranked by how well they match ACS Bio & Med Chem Au's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

1
Enhancing the efficacy of siRNA Antibody Oligonucleotide Conjugates (AOCs) through chemical design

Hayes, O. G.; Rädler, J. A.; Filipiak, E.; Czapik, T.; Roudi, S.; Ojansivu, M.; Saranya Ilamathi, H.; Marquant, A.; Huang, Y.; Wiklander, O. P.; Zain, R.; Honcharenko, M.; EL Andaloussi, S.

2026-09-23 biochemistry 10.64898/2026.09.23.753708 medRxiv
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Antibody-oligonucleotide conjugates (AOCs) offer a promising solution to delivery challenges of therapeutic oligonucleotides. However, the relationship between their complex chemical architectures and biological activity remains poorly understood, limiting the development of important structure-function relationships. For siRNA-containing AOCs, increasing the siRNA-to-antibody ratio beyond one (drug-to-antibody ratio, DAR>1) reduces potency, attributed to altered pharmacokinetics arising from increased negative charge density. Here, we investigated whether simple chemical modifications could improve AOC efficacy and mitigate limitations associated with higher DAR. Introduction of a single C16 lipid modification to the siRNA significantly enhanced target gene silencing compared to the unmodified AOC. Extending this modification to a DAR2 architecture, in which two siRNAs are conjugated per antibody, restored the loss of activity associated with increasing DAR from 1 to 2. Notably, at an equivalent siRNA dose (1 mg/kg), the DAR2-C16 AOC requires half the amount of antibody while achieving knockdown comparable to the DAR1-C16 AOC. We also developed a charge-balancing ionizable linker (CBIL) designed to partially compensate for the negative charge of siRNA. Incorporation of the CBIL enhanced target gene silencing in heart and skeletal muscle without a corresponding increase in hepatic activity, resulting in a shift toward greater extrahepatic activity relative to liver. Together, these findings demonstrate that chemical modification of both the siRNA payload and antibody-siRNA linker can be used to tune AOC potency and tissue activity, while enabling higher payload loading without compromising efficacy. These results establish chemical design as an important strategy for expanding the architecture and therapeutic potential of AOCs.

2
KRASG12C Inhibition Remodels the Non-Small Cell Lung Cancer Surfaceome to Uncover Targetable Vulnerabilities

Padhye, A.; Kang, K.; Kong, F. Y.; Sindoni, N.; Yu, Q.; Jiang, B.; Chang, W.-H.; Coker, O.; Kim, E.; Dilly, J.; Shin, M.; Paulo, J. A.; Sprouffske, K.; Brachmann, S. M.; Stalnecker, C. A.; Aguirre, A. J.; Mancias, J. D.

2026-10-02 cancer biology 10.64898/2026.10.01.756013 medRxiv
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Mutant-selective and pan-RAS(ON) multi-selective inhibitors have improved clinical outcomes for patients with RAS-driven cancers; however, adaptive resistance limits the depth and durability of response. Using an integrated genetic, transcriptomic, and mass-spectrometry-based quantitative temporal proteomic platform, we profile the adaptive response to KRASG12C inhibitors (KRASi) in KRASG12C-mutant lung adenocarcinoma models. Our analyses reveal remodeling of signaling pathways and the cell surface proteome, including cell surface proteins selectively upregulated across cell lines, tumor models, and treatment durations. Folate receptor alpha (FOLR1) emerged as a therapeutically actionable target that is significantly upregulated with KRASi and is part of a broader acute cellular state transition characterized by acquisition of an epithelial identity. Combining KRASi with mirvetuximab soravtansine-gynx, a clinically approved FOLR1-targeting antibody drug conjugate, enhanced tumor cell cytotoxicity and deepened response and tumor control in cellular and in vivo models. Additionally, this work represents a comprehensive multi-omic resource characterizing non-genetic temporal adaptation to KRASi for future mechanistic and therapeutic investigations.

3
Size-dependent effect of site-specific polyethylene glycol modification of trastuzumab on the antibody functions

Tsutsui, Y.; Ohno, H.; Akiba, H.

2026-09-24 biochemistry 10.64898/2026.09.23.753936 medRxiv
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Polymer modification of antibodies has attracted attention for enhancing antibody functionality. Modification with polyethylene glycol (PEG) or biopolymers such as antibody-oligonucleotide conjugates has been investigated. Although direct effects at the modification site have been understood, distal effects of modifications on intrinsic antibody functions such as antigen-binding and Fc receptor-binding activities remain poorly characterized. In this study, we prepared site-specifically PEGylated trastuzumab to evaluate the effects of the modification site and the size of PEG chains on antibody functions. Reporter gene assays revealed a significant reduction in antibody-dependent cell cytotoxicity (ADCC) activity in a site- and size-dependent manner. Both the reduction in interaction with the antigen and Fc{gamma}RIIIa were observed in a size-dependent manner. Interestingly, the effect of the modification site was only observed for ADCC activity, which suggests that the higher-order structure of the modified antibody plays a critical role in effector function. These results provide molecular design guidelines for the polymer modification of antibodies.

4
aaRSID, an engineered pyrrolysyl-tRNA synthetase platform for multi-probe proximity proteomics

Wang, Z.; Ruenkam, T.; Schelling, R. E.; Juvekar, V.; Mathew, B.; Deangphare, T.; Li, W.; Liu, Y.; Slavoff, S. A.; Uttamapinant, C.; Loh, K. H.

2026-09-24 biochemistry 10.64898/2026.09.22.753581 medRxiv
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Proximity labeling (PL) methods utilize spatially targeted chemical or enzymatic generation of a diffusible, reactive intermediate to covalently tag neighboring proteins in living systems. Unlike other tools for studying molecular interactions, PL can detect transient protein relationships with high spatial and temporal sensitivity, allowing for insight into their roles in biological processes. However, current enzymatic PL tools, such as TurboID and APEX2, are limited by their substrate structure and chemistry, which can generate significant background and/or perturb cellular physiology. To address these limitations, we have developed aminoacyl-tRNA synthetase ID (aaRSID), a PL tool that leverages an engineered pyrrolysyl tRNA synthetase (PylRS) for proximity labeling of proteins. We chose PylRS because it can catalyze promiscuous lysine labeling in the absence of its cognate tRNA and utilize a variety of non-canonical amino acids (ncAAs) as substrates. Here, we demonstrate aaRSID's intrinsic proximity labeling activity, use directed evolution to improve this activity, and apply the improved mutant (aaRSID-Ma1.3) for subcellular proteomics and multiplexed imaging. Our work establishes aminoacyl-tRNA synthetases as a new PL enzyme class and introduces a versatile chemical platform for developing ncAA-derived probes to map cellular microenvironments, greatly expanding the applications possible of PL technology.

5
Protoribosomal condensate formation across cationic chemistries

Codispoti, S.; Giacobelli, V. G.; Fricek, M.; Verner, V.; Novakova, J.; Masek, M.; Bokac, A.; Krystufek, R.; Soucek, R.; Kolar, M.; Zanchetta, G.; Hlouchova, K.

2026-09-30 biochemistry 10.64898/2026.09.29.755306 medRxiv
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Early ribonucleoprotein systems likely required mechanisms to concentrate and organize RNA. Modern ribosomes use Mg2+ and evolved Lys/Arg-rich protein extensions to stabilize their RNA backbone. Before templated synthesis, however, peptide formation likely generated heterogeneous sequence populations rather than reproducible ribosomal sequences. Here, we compare Mg2+, ribosomal peptides, and statistical peptide libraries in organizing a 136-nucleotide model of the peptidyl transferase center (sPTC). Mg2+ condenses sPTC only at a large excess of positive charge following thermal annealing, producing largely arrested libraries. Acidic conditions further promote condensation. Ribosomal peptides instead promote coacervation near charge stoichiometry and form droplets that readily fuse. Several statistical peptide libraries also coacervate with sPTC, despite comprising heterogenous mixtures rather than a single defined sequence. Increasing mean positive charge favors condensation, but Lys/Arg-containing libraries undergo liquid-liquid phase separation more readily and across broader conditions than matched libraries containing the prebiotically plausible diaminopropionic acid (Dpr) and diaminobutyric acid (Dab). Atomistic computer simulations implicate Arg as a major source of this difference, as it can form more numerous and longer-lived hydrogen bonds with RNA, while competitive partitioning experiments show preferential condensate recruitment in the order Arg > Lys > Dab > Dpr. Together, our findings show that peptide-RNA coacervation can be triggered collectively by statistical peptide ensembles, providing a plausible route to protoribosomal organization without peptide sequence-specific optimization. Cationic chemistry shapes condensate formation and material properties, suggesting that amino acid alphabet formation could have broadened the conditions supporting liquid-like protoribosomal assemblies.

6
Buffer tolerance landscape of LbCas12a trans-cleavage efficiency

Alcantara, R.; Spurio, R.; Milon, P.

2026-09-24 biochemistry 10.64898/2026.09.23.753913 medRxiv
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Numerous CRISPR-Cas systems have been developed for molecular detection of genetic elements exploiting the trans-cleavage activity of LbCas12a combined with short fluorescent probes. Alongside, a large variability of buffer conditions has been reported. However, how solution chemistry balances enzymatic turnover, signal stability, and detection performance have not been systematically defined. Here, we evaluated how the interplay between anions (chloride vs. acetate), additives, sequence probes, and ionic strength contributes to LbCas12a trans-cleavage activity. Buffer composition screening revealed that chloride-based buffers maintain a low background but slow catalytic rates, meanwhile acetate-based buffers accelerate enzymatic turnover with and without the target DNA sequence, increasing non-specific signals. Reducing agents and surfactants were the best enhancer combinations, improving cleavage performance by increasing ternary complex formation (Km). High salt concentrations only slightly improved the reaction kinetics. Finally, the 5FAM-TTATT-3BHQ-1 reporter showed the best balance between signal intensity and nonspecific background. Our findings indicate that LbCas12a tolerates a vast buffer composition landscape, maintaining robust trans-cleavage activity and detection performance. However, conditions that enhance catalytic activity simultaneously increase nonspecific probe cleavage and higher background, resulting in lower detection performance. Therefore, assay optimization should prioritize detection performance rather than maximal fluorescence output, where solution chemistry is a critical determinant.

7
Sequence-specific and programmable catalytic degradation of extracellular microRNAs by membrane-anchored DNA nanomachines

Zhou, Z.; Zhang, L.; Wang, X.; Zhang, C.; Yan, Q.; Wang, S.; Liu, H.; Su, X.

2026-10-01 biochemistry 10.64898/2026.09.30.755580 medRxiv
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Extracellular microRNAs (miRNAs) contribute to metastasis through communication between tumour cells and their microenvironment, yet their sustained, sequence-selective depletion remains challenging. Here we report Programmable RNA-Intercepting Molecular Eraser (PRIME), a membrane-anchored DNA nanomachine that organizes miRNA recognition and catalytic degradation at the cell surface. A double-tetrahedral DNA scaffold positions a programmable recognition hairpin beside RNase H. Target binding generates an RNA/DNA hybrid for RNase H-mediated cleavage, and product release resets the hairpin for subsequent degradation cycles. Membrane-anchored PRIME depleted matched extracellular miRNAs by 70.6-89.4% across lung, breast and cervical cancer cell models. Multi-target PRIME (M-PRIME) inhibited migration by 71.3-96.0% in Transwell assays across these models. To evaluate its therapeutic potential, we established an orthotopic lung-tumour model and an early-intervention breast-cancer lung-colonization model in mice. Aptamer-directed M-PRIME combined with gemcitabine reduced pulmonary tumour burden by 74.5% in established lung tumours and 93.2% in the lung-colonization model. These effects were consistent with PRIME-mediated extracellular miRNA degradation, with circulating target miRNA levels reduced by 77.5-98.7% relative to gemcitabine alone. Together, these findings establish a programmable material strategy for sustained extracellular RNA depletion and support its potential to enhance chemotherapy in preclinical tumour models.

8
A scalable recombinant pipeline for disulphide-stapled peptides

Flores Bueso, Y.; Gokce-Alpkilic, G.; Jeung, J.; Rettie, S.; Li, X.; Tangney, M.; Baker, D.; Bhardwaj, G.

2026-09-30 biochemistry 10.64898/2026.09.29.755317 medRxiv
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Constrained macrocyclic peptides can engage protein surfaces that resist both small molecules and biologics but producing them at library scale still depends on chemical synthesis and macrocyclisation workflows that are slow, specialised and hard to parallelise. We describe a recombinant pipeline for disulphide-stapled cyclic peptides, compatible with 96 well plates, that lowers this barrier. Peptide-encoding sequences are introduced by extension PCR and in vivo assembly (IVA) cloning at about $2 per variant, expressed as small ubiquitin-like modifier (SUMO) fusions secreted to the oxidising periplasm, where the intramolecular disulphide forms spontaneously, and purified by immobilised metal-affinity chromatography (IMAC) with analytical size-exclusion chromatography (SEC). The route from a list of designs to characterised material takes about one week, much of it unattended. Applied to a 60-design library across nine protein targets, the pipeline gave purified products for all 60 designs, at a median total soluble yield of approximately 135 micrograms per 6 mL culture (range 9 to 261) that varied by target. Ellman's assay across 38 designs showed disulphide-formation failure to be sequence-driven and uncorrelated with yield, detecting a failure mode invisible to chromatography. Surface plasmon resonance confirmed target binding and showed that the recombinant SUMO fusion constructs retained affinities comparable to their corresponding peptide-only forms. Complementary to general-purpose recombinant platforms, the pipeline enables higher-throughput disulphide macrocycle screening and is amenable to partially or fully automated workflows.

9
Cellular uptake of folate-olaparib conjugates via folate receptor-mediated endocytosis: Potential for selective delivery of DNA damage response inhibitors into tumour cells

Bavetsias, V.; Pickard, L.; Diaz-Sanchez, S.; Gowan, S.; Wood, F.; Ruddle, R.; Wong, C.; Sharif, H.; Raynaud, F.; Burke, R.; Wang, A.; Blagg, J.; Kirkin, V.; Rossanese, O.; Banerji, U.

2026-09-24 biochemistry 10.64898/2026.09.23.752340 medRxiv
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The folate receptor (FR) is overexpressed in a range of human tumours including ovarian cancer cells. We propose that the overexpression of the FR on the surface of ovarian tumour cells could be exploited for the selective delivery of a DNA damage response inhibitor (DDRi) in the form of an intact folate drug conjugate (FDC). This approach would improve the therapeutic index of the parent DDRi facilitating combination studies of the DDRi-based FDC with DNA damaging chemotherapy. FR-mediated cellular uptake of the proposed folate drug conjugates is requisite for FDC selective delivery into tumours. In this study, we synthesised a series of olaparib-based folate conjugates that maintained the biochemical PARP1 inhibition associated with olaparib and showed binding affinity for the folate receptor. Significantly, we identified compounds 10b and 11 that selectively enter FR overexpressing tumour cells via folate receptor-mediated endocytosis in their intact form and engage with their target as demonstrated by the potent inhibition of PARylation (KB cells, PARylation IC50 = 5.7 and 3.9 nM; respectively).

10
Ambient-Condition Visualization of Metalloenzyme Reactive Intermediates Enabled by the SHINERS Paradigm

Liao, L.; Li, Q.-Q.; Zhang, X.; Liu, J.; Chen, Z.-H.; Zhou, Y.; Bao, Z.; Ma, H.; Yang, L.; Wang, X.; Wang, C.; Ren, B.; Li, J.-F.; Wang, B.

2026-10-06 biochemistry 10.64898/2026.10.03.756395 medRxiv
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Reactive metal-oxygen intermediates are central to metalloenzyme catalysis, yet their low populations and short lifetimes make vibrational characterization under aqueous reaction conditions challenging. Here, we establish shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) as a powerful vibrational approach for visualizing reaction-associated metal-ligand signatures of reactive metalloenzyme states. Across the heme and non-heme iron enzymes TauD, VioC, CYP119, and TqaLNc, isotope-sensitive features provide vibrational information on reactive coordination states. In TauD and VioC, isotope-sensitive features provide vibrational characterization of Fe(IV)=O intermediates. In CYP119, an isotope-sensitive Fe(IV)=O vibration is assigned to P450 Compound I generated by m-CPBA, including under lauric-acid turnover conditions. Most notably, in TqaLNc, combined 18O- and 15N-sensitive vibrational responses support formation of the proposed (R)HN-Fe(IV)=O coordination state and the dynamic-coordination mechanism underlying selective C-N bond formation. These results demonstrate that SHINERS can serve as a powerful technique for the in situ vibrational visualization of reactive intermediates and their coordination states in metalloenzyme catalysis.

11
Peptide frontier-orbital gaps narrow by backbone electrostatics

Wu, X.; Fu, W.

2026-10-06 biochemistry 10.64898/2026.10.05.756722 medRxiv
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Aromatic side chains carry the optical and redox chemistry of peptides, and lengthening one is widely expected to extend its conjugation and narrow its HOMO-LUMO gap. We test that expectation with plane-wave density functional theory on 22 isolated neutral peptides NH2-(X)n-COOH (X = Phe, Tyr, Trp, Cys; n = 1 to 5, and n = 10 for Cys and Trp). The gap does narrow, at the same rate for all three aromatic residues, i.e., -0.17 to -0.18 eV per residue, even though benzene, phenol and indole are very different chromophores. Residue-resolved projections reveal why: nothing delocalises. Every aromatic frontier orbital is 97 to 100 % confined to a single residue and the HOMO participation number saturates at one ring. Each residue instead keeps its own local gap: for Trp it is invariant to within 0.03 eV over n = 2 to 10, while over that same span the global gap falls by 1.19 eV. The global gap is therefore an extreme-value functional of the residue site energies, gap(n) =<g_f>-{Delta}(n), whose alignment penalty accounts for the entire effect: the polar backbone generates a monotonic internal electrostatic ramp that leaves the two gap edges at opposite ends of the chain, 32 [A] apart. We set out the resulting design rules for peptide-based bio-organic semiconductors.

12
Multi-attribute characterisation of mRNA via MazF endoribonuclease and LC-MS workflows

Welbourne, E. P.; Owen, G. R.; Wright, L. P.; Trabulo, S.; Kis, Z.; Dickman, M. J.

2026-09-24 biochemistry 10.64898/2026.09.23.753728 medRxiv
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The rapid expansion of mRNA-based medicines has driven demand for robust, high-resolution analytical methods capable of characterising critical quality attributes including sequence identity, 5[prime] capping efficiency, and poly(A) tail length and heterogeneity. Here, we present two complementary liquid chromatography-mass spectrometry based workflows for mRNA characterisation, both based on site-specific digestion with the endoribonuclease MazF from Escherichia coli. A middle-up approach, optimised via specific 5[prime]-ACA cleavage enables rapid characterisation via oligoribonucleotide mass mapping providing complete sequence coverage and simultaneous assessment of 5[prime]-capping efficiency and 3[prime]-poly(A) tail length and heterogeneity. This workflow was successfully applied to three different mRNA constructs, NLuc, eGFP and FLuc mRNAs, achieving sequence coverages of 100%, 87%, and 74%, respectively. A complementary bottom-up approach, employing less specific 5[prime]-ACX cleavage enables tandem mass spectrometry-based sequencing of shorter oligoribonucleotides and detailed characterisation via mRNA sequence mapping. Applied to SARS-CoV-2 Spike Protein mRNA, this method yielded 50% sequence coverage based on unique oligoribonucleotides with MazF alone, extended to 90% by combining MazF, partial RNase T1, and partial RNase U2 digests. Together, these workflows provide a flexible, orthogonal platform for both high-throughput quality assessment and in-depth primary sequence characterisation of mRNA vaccines and therapeutics.

13
Coumarin-based blue excitable probe for functional screening of dehalogenase activity

Mion, S.; Mallet, M.; Louis, Y.; Fontanay, S.; Ruaudel, F.; Bastian, F.; Jacolot, M.; Popowycz, F.; Oger, P. M.

2026-10-05 biochemistry 10.64898/2026.10.02.756220 medRxiv
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In the enzymatic toolbox of depollution, hydrolytic dehalogenases are of particular interest for the bioremediation of organohalogenated compounds. To better identify and characterize these enzymes, it is important to develop appropriate sensing methods. Fluorescent probes for dehalogenase detection have been developed in the past years, however, to this date none were available for application using the common FITC parameters (i.e. excitation laser at 488 nm). To address this limitation, we herein report a new fluorescent probe, COU4-Cl, excitable in the violet (405 nm) and blue (488 nm) wavelengths adapted for the detection and characterization of haloalkane dehalogenases. Its applicability is discussed and evaluated in comparison to the previously described COU2-Cl probe only excitable in the violet (405 nm). This study shows the advantages and complementarity of the two probes, and further demonstrate their application for the discrimination of dehalogenase activity in whole cell assays.

14
Rational Design of 5' UTRs for Optimized mRNA Expression and Cost-Effective, Rapid Analysis of Capped mRNA

Fang, Y.; Liu, T.; Liang, Y.; Wang, X.; Shao, M.; Wang, C.; Yu, J.; Sun, Y.; Zhang, P.; Qian, Q.

2026-10-10 bioengineering 10.64898/2026.10.08.757771 medRxiv
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In vitro-transcribed (IVT) messenger RNA (mRNA) therapeutics require rigorous quality control of 5' capping efficiency and 3' poly(A) tail length, both of which constitute critical quality attributes (CQAs). Current analytical workflows for these CQAs rely on hybridization with nucleic acid probes and biotin-based affinity purification, which constrain throughput and increase per-assay cost. Here, we report a rationally designed 5' untranslated region (5' UTR) that sustains high translational efficiency while enabling probe-free, one-step purification for rapid quantification of capping efficiency and poly(A) tail length distribution. This approach exploits a strategically engineered 5' UTR incorporating a purine-only RNase A-resistant fragment terminating at a single pyrimidine cleavage site, together with a translation-enhancing element comprising an N6-methyladenosine (m6A) deposition motif and an 18S rRNA complementarity sequence. This dual-function design accommodates GA-rich sequence segments without compromising mRNA translational output. Compared with conventional probe- and biotin-dependent workflows, the present method substantially reduces cost and processing time and is compatible with simultaneous detection of segmented AmGn poly(A) tail variants. This integrated platform provides a simplified, probe-free and construct-universal for high-throughput in-process control (IPC) of mRNA therapeutics.

15
Orthogonal Chemical Proteomic Strategies Reveal the Cholesteryl Ester Interactome in Mammalian Cells

Chandramouli, A.; Sharma, K.; Kallattu, A.; Katkar, C.; Deshmukh, M.; Thakral, P.; Chakrapani, H.; Kamat, S. S.

2026-09-23 biochemistry 10.64898/2026.09.21.753363 medRxiv
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Cholesteryl esters (CEs) are widely regarded as inert storage forms of cholesterol, yet their potential to directly engage cellular proteins remains largely unexplored. Here, we establish an integrated chemical proteomic platform to systematically define CE-protein interactions in mammalian cells. We developed and comparatively deployed three orthogonal photoaffinity labeling strategies: (i) metabolic assembly of a bifunctional CE probe through endogenous acyl-CoA:cholesterol acyltransferase activity, (ii) direct delivery of a structurally defined diazirine-alkyne CE analog, and (iii) fragment-assisted subtraction using sterol and fatty acyl control probes to resolve interactions dependent on the intact esterified scaffold. Each probe system was rigorously validated by lipidomics and UV-dependent crosslinking prior to quantitative proteomic analysis. Integration of these complementary modalities identified 495 CE-associated proteins spanning enzymes, transporters, scaffolding proteins, and canonical sterol-binding families. The limited overlap across strategies reveals that lipid-protein engagement is strongly conditioned by biosynthetic origin, probe topology, and intracellular routing. Functional and database annotations further demonstrate enrichment of druggable and disease-linked proteins, connecting CE interactions to metabolic, neurological, and cardiovascular pathways. Collectively, this work provides the first systems-level map of CE-protein interactions and establishes a generalizable, multimodal framework for chemically resolving lipid-protein interactomes.

16
Extracellular vesicle cross-linking coupled with solid-phase purification facilitates discovery of ribonucleoprotein complexes assembled on EV RNAs.

Dhyani, R.; Clarke, S.; Kuroda, M.; Sanada, Y.; Gorum, M.; Barman, B.; Weaver, A.; Nakamura, T.; Ascano, M.

2026-10-06 cancer biology 10.64898/2026.10.03.756357 medRxiv
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Extracellular vesicles (EVs) are fundamental mediators of intercellular communication that transfer macromolecular cargo, including proteins and RNAs, to functionally reprogram recipient cells. However, the molecular processes by which transferred ribonucleoprotein (RNP) complexes engage recipient host machinery to influence cellular behavior are poorly understood, primarily due to a dearth of methods capable of tracking these post-transfer interactions. To address this gap, we developed two complementary chemical biology platforms: EV-CLASP and EV(r)-CLASP. While EV-CLASP maps the native, intra-vesicular RNP landscape packaged within the EV, EV(r)-CLASP captures post-transfer dynamics by identifying the host proteins that directly associate with EV-derived RNAs following cellular uptake. Both approaches leverage metabolic labeling and photo-crosslinking for high-specificity recovery. Donor cells are cultured with 4-thiouridine (4SU) to biosynthetically label newly synthesized RNAs during EV biogenesis. Purified EVs can be crosslinked using 365 nm UV light to capture intra-vesicular RNP composition. Alternatively, 4SU-labeled EVs can be delivered to recipient cells and subsequently crosslinked to identify the primary physical interactions formed within the recipient-cell environment. Crosslinked RNP complexes are isolated under stringent conditions using solid-phase reversible beads to minimize background, followed by quantitative mass spectrometry for protein identification. Together, EV-CLASP and EV(r)-CLASP provide a robust, versatile framework for defining the dynamic RNP assemblies that facilitate extracellular RNA communication, offering a powerful toolkit to uncover novel RNA-associated regulatory networks, therapeutic targets, and biomarkers across diverse biological and disease contexts.

17
Programming primary human T cells to deliver gene editing machinery

Meixiong, J.; Zginnyk, O.; Chow, L.; Shy, B. R.; Spitzer, M. H.

2026-10-02 immunology 10.64898/2026.09.30.753584 medRxiv
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Clinical applications of gene editors including CRISPR-Cas9 are limited by the cell-type specificity and tissue penetrance of current in vivo delivery options. Cell-mediated gene editor delivery could overcome these obstacles. To date, systems utilizing immortalized cell lines have demonstrated gene editor delivery in vitro. Because T cells traffic throughout the organism and engage in intercellular communication with individual target cells, we wondered whether they could be engineered to deliver gene editing machinery. Here, we demonstrate that primary human T cells can produce retroviral-based enveloped delivery vehicles (EDVs) packaging functional Cas9 ribonucleoproteins. When paired with fusogenic VSV-G, T cell-generated Cas9-EDVs edited a diverse array of target cells. We developed a miniaturized Moloney murine leukemia virus-based system that proved superior to existing architectures in this context and optimized both lentiviral and site-specific knock-in approaches for T cell engineering. These Enveloped Particle Information Courier- (EPIC-) T cells offer key advantages as delivery systems.

18
Asymmetric assembly of congested contiguous stereocenters via photobiocatalytic three-component radical coupling

Hu, Q.; Zheng, C.-X.; Mai, B. K.; Liu, P.; Yang, Y.

2026-09-28 biochemistry 10.64898/2026.09.25.754468 medRxiv
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Despite rapid advances in new-to-nature biocatalysis, trimolecular enzymatic reactions that generate previously inaccessible molecular entities, particularly those bearing well-defined, congested stereochemical dyads, remain exceedingly rare. Here, we report a novel diastereo- and enantioselective photobiocatalytic three-component radical coupling unknown in both organic chemistry and enzymology, enabled by cooperative catalysis employing an evolved pyridoxal biocatalyst and a transition-metal photosensitizer. Directed evolution using high-throughput photobiocatalysis furnished two threonine aldolase variants, enabling the stereoselective assembly of contiguous tri- and tetrasubstituted stereocenters as well as vicinal tetrasubstituted stereocenters, which were long regarded as a challenging goal for stereoselective radical chemistry and asymmetric catalysis. Furthermore, a variety of radical precursors, including alpha-iodoesters, alpha-iodoamides, alpha-iodoketones, and alpha-iodonitriles, could be transformed into structurally diverse, densely substituted non-canonical amino acid derivatives via C-H functionalization with excellent stereocontrol. Leveraging the broad substrate compatibility of engineered pyridoxal biocatalysts, combinatorial biocatalysis was achieved by simultaneously varying all three coupling partners, delivering products with a 98% success rate. Collectively, this diversity-generating multicomponent photobiocatalytic radical coupling afforded a powerful strategy for addressing long-standing challenges in asymmetric catalysis while enabling access to valuable stereochemically complex small molecules with applications in medicinal chemistry.

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Photobiocatalytic Diastereo- and Enantioselective Synthesis of Non-Canonical Amino Acids Bearing Challenging Stereochemical Dyads and Triads

Bo, Z.; Cheng, L.; Zhang, X.; Singh, A.; Liu, P.; Yang, Y.

2026-10-09 biochemistry 10.64898/2026.10.07.757362 medRxiv
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Catalyst-controlled stereodivergent synthesis of acyclic molecules bearing multiple stereogenic centers remains a longstanding challenge in asymmetric catalysis, particularly through intermolecular radical C-C coupling. Here, we report the directed evolution of pyridoxal 5'-phosphate (PLP)-dependent biocatalysts for the stereodivergent synthesis of non canonical amino acids bearing either skipped , {gamma}-stereochemical dyads or contiguous , {beta}, {gamma}-stereochemical triads. Starting from a thermophilic tryptophan synthase {beta}-subunit, protein engineering generated complementary enzyme variants that selectively construct three of the four possible , {gamma}-stereoisomers through biocatalyst-controlled reversal of both remote {gamma}-stereochemistry and proximal -stereochemistry. These engineered enzymes catalyzed intermolecular radical C-C bond formation with a broad range of secondary alkyltrifluoroborates, affording , {gamma}-disubstituted amino acids in excellent yields and stereoselectivities. Furthermore, directed evolution enabled efficient {beta}-dehydroxylative radical coupling of the non-native threonine-derived aminoacrylate intermediate, providing amino acids bearing contiguous , {beta}, {gamma}-stereochemical triads with up to 96:4:<0.1:<0.1 d.r. and >99:1 e.r.. To further demonstrate the synthetic utility of this platform, the stereochemically enriched amino acids were transformed into valuable {gamma}-chiral amines through engineered PLP dependent tryptophan decarboxylases, establishing a dual PLP enzyme based biocatalytic cascade for the enantiodivergent synthesis of privileged amine scaffolds. Molecular dynamics simulations reveal that enzyme controlled {gamma}-stereoselectivity originates from active-site remodeling that modulates {pi}-{pi} interactions and steric contacts governing the facial selectivity of the radical addition step. This work expands the synthetic capabilities of radical biocatalysis by enabling catalyst-controlled stereodivergent assembly of complex acyclic stereochemical arrays and establishes engineered PLP enzymes as versatile catalysts for the synthesis of stereochemically complex amino acids and chiral amines.

20
Programmable sequence-resolved in situ profiling of glycoRNA-protein interactomes by GlycoRNA-Map

Zhang, X.; Zhu, Y.; Baumer, K.; Lu, Y.; Fu, Y.; Liao, J.; Shao, X.; Chang, Y.; Qiao, E.; Dong, H.; Valverde, A. S.; Yeh, H.-C.; Chen, S.-H.; Renata, H.; Ma, Y.

2026-09-30 biochemistry 10.64898/2026.09.29.755375 medRxiv
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Cell-surface glycoRNAs participate in diverse biological processes, but they were investigated as pooled populations and the protein interactome of individual glycoRNA species remain unresolved. Here we develop GlycoRNA-Map, a programmable photocatalytic proximity-labeling method that maps proteins surrounding sequence-defined endogenous glycoRNAs on living cells. A sialic-acid-binding aptamer and an RNA-hybridization probe jointly recruit a fluorophore-modified oligonucleotide through dual recognition of the glycan and RNA moieties of glycoRNAs. Light-activated biotinylation followed by quantitative mass spectrometry identified 200-418 enriched proteins for each of five glycoRNAs in A549 cells. Comparison of these proteomes revealed limited overlap among different glycoRNA sequences and across cell types, demonstrating that glycoRNA-associated protein environments depend on both RNA identity and cellular context. Transforming growth factor-{beta} receptors 1 and 2 (TGFBR1 and TGFBR2) were identified in the proximal proteomes of multiple glycoRNAs. Removal of cell-surface RNAs enhanced TGF-{beta} receptor signaling and promoted cell migration, demonstrating that glycoRNAs can functionally regulate extracellular signaling by interacting with their protein neighborhoods. GlycoRNA-Map thus provides an accessible strategy for resolving sequence-specific glycoRNA-protein interactome and discovering their roles in membrane signaling.