FEBS Letters

Climate-smart agriculture (CSA) dominates African agricultural policy discourse, yet fifteen years post-conceptualization, its transformative potential remains unrealized. Bibliometric analysis of 161 Scopus-indexed publications (2014-2025) reveals exponential field growth (31.3% annually) coupled with on technical dimensions and systemic neglect of financial mechanisms. Network analysis (VOSviewer), semantic mapping and citation bibliometrics expose cognitive oligopolisation--wherein 1.8% of authors generate 45% of output--geographical fragmentation into weakly connected regional clusters, and critical underrepresentation of the vulnerable Sahel. Despite 46.6% of publications addressing economic themes, merely 5.6% rigorously integrate financial analysis with adoption variables; terms including investment, cost-benefit and climate finance remain absent from major semantic clusters. The concept of structural financial ambiguity is introduced to characterize the maintenance of CSA in operational indeterminacy through academic discourse that substitutes description for actionable financial theorization. Paradigmatic transformation conditions are identified through emerging scholarship employing discrete choice experiments and cost-benefit evaluations to construct requisite knowledge foundations. Findings indicate that without comprehensive theorization of microfinance, digital finance, index-based insurance and payments for environmental services, international climate commitments risk implementation failure due to absence of scientifically validated financial instruments rather than technical solutions.

Research using model organisms to tackle questions in life sciences and biomedical sciences has been in the spotlight of scientific literature for the better part of the twentieth century. This attention has perceptibly faded over the last twenty years, at least. We set to document this process by examining the publication trends of 48 journals encompassing a broad range of topics and impact factors for eight classic model organisms. We found that the representation of model-organism research has been in continuous decline in the last three decades, with a significant acceleration since 2010. We investigated the origin of the change, from the size of research communities to the shifts in topics and in use of model organisms. While model organism communities appear stable, model organism papers are outpaced by the rest of scientific literature. Also, among papers using model organisms, we note a progressive shift toward applied research, with differences between different model organism species. The mouse, in particular, logically remains the preferred system to study diseases, while non-mouse model organisms continue to be used predominantly to dissect mechanisms of life. We reflect on the consequences of the fading representation that we measured for the future of life sciences. Fundamentally, model organisms afford a direct access to causality in life sciences and their fading from the picture may impact life sciences as a whole. More pragmatically, it will also affect funding, and thereby jeopardizes the maintenance of model organism resources such as repositories built over decades.

Seismic shifts within academia over the last several decades have seen the growth of biomedical PhD recipients alongside the relative stagnation of tenure-track research-intensive faculty careers (RIFCs). This hypercompetitive academic job market has prompted interest in the paths of those who attain RIFCs. Understanding what drives recent biomedical PhDs to make their career decisions and persist toward them requires a clear picture of how career perceptions, motivations, and intentions develop and crystallize over time. Using annual in-depth interviews across nearly two decades, this report explores the evolution of career thinking and differentiation among 40 who attained a RIFC from diverse starting points to their attainment of a RIFC. Participants strategies for navigating early scientific experiences were patterned by their varied educational and socioeconomic backgrounds. Nearly half of participants did not start with or maintain stable interest in RIFCs, exhibiting changes in both PhD and postdoctoral phases. Participants highlighted six drivers toward RIFCs including desire for independence/autonomy and contributing to knowledge/health. Our results are instructive for trainees and mentors guiding career exploration and differentiation.

Understanding what is requisite for attaining a biomedical faculty career is crucial for guiding trainees preparing for these roles. For nearly two decades, we have collected accounts of biomedical training and career transitions from a large cohort through annual in-depth interviews and tracking of competencies and achievements. This paper elucidates the common and varied credentials of 40 who entered research-intensive faculty careers (RIFCs). Participants completed PhDs and postdocs in a range of research-intensive institutional settings. Developing research independence and a niche were essential to RIFC attainment, and mentors played a crucial role in this development. Counter to common assumptions, high-prestige publications and grants were not in and of themselves necessary for RIFC attainment. Our findings can aid RIFC aspirants and mentors who guide them.

Microtubules are dynamic filaments of tubulin heterodimers that comprise an essential part of the eukaryotic cytoskeleton1. The nucleotide state of tubulin controls microtubule dynamics: stable GTP-microtubules favor polymerization, whereas unstable GDP-microtubules drive depolymerization2. Anticancer compounds such as Taxol (paclitaxel) target microtubule dynamicity by preventing microtubule depolymerization3,4. Despite decades of work, the molecular basis of microtubule dynamics remains poorly defined. Using cryo-EM, we determined [~]2.2 [A] structures of human microtubules in GTP-like (GMPCPP) and GDP states. Comparison of these two states revealed switch-like structural changes as tubulins transition from the pre-hydrolysis (GMPCPP) to the post-hydrolysis (GDP) state. Additional structure determination of Taxol-bound microtubules at [~]2.2 [A] showed that Taxol binding converts the microtubule lattice into a pre-hydrolysis state by reversing the structural switches flipped during GTP hydrolysis. Focusing our analysis on the microtubule seam shows that the pre-hydrolysis conformation of GMPCPP or Taxol-GDP exhibits favorable lateral interactions at the seam, with lattice deformations clearly visible at the GDP seam. Together, our data show the existence of structural switches in tubulin that are coupled to the nucleotide state and are exploited by Taxol to stabilize microtubules into a pre-hydrolysis-like state. (191 words)

Pulmonary vascular remodelling is common in patients with chronic obstructive pulmonary disease (COPD). Vascular endothelial growth factors (VEGFs) are key mediators in angiogenesis and vascular remodelling and exist in different isoforms. VEGF-A is the most potent angiogenic member binding to VEGF receptor 2 (VEGFR2). There are, however, few studies on other isoforms, as VEGF-C, and its receptor VEGFR3 in COPD and subsequent impact of cAMP therapies on VEGF isoforms. Our aim was to evaluate the VEGF isoform synthesis in primary distal lung fibroblasts from control subjects (non-smokers (n=6) and ex-smokers (n=4), and COPD subjects with GOLD stage II (n=4) or GOLD stage IV (n=6), and the expression of VEGFR2 and VEGFR3 in human lung tissue. Primary lung fibroblasts were exposed to the cAMP generating therapies formoterol, iloprost, or roflumilast, the adenylyl cyclase activator forskolin or to transforming growth factor (TGF)-b1. VEGF isoforms were evaluated with ELISA. VEGF-C release was not significantly altered by TGF-{beta}1, in contrast to the increased levels of VEGF-A, in all fibroblasts. VEGF-C was significantly decreased by iloprost, forskolin and formoterol, whereas VEGF-A was significantly increased by iloprost and forskolin, with differences in release pattern between and within fibroblasts from control and COPD subjects. Exposure to VEGF-C specifically towards VEGFR3 decreased proliferative rate in human lung fibroblasts and bronchial epithelial cells. VEGFR2 and VEGFR3 were both present in parenchymal lung tissue and VEGFR2 in pulmonary blood vessels. in both healthy and COPD, whereas there was elevated expression of VEGFR3 in bronchial epithelium. In conclusion, TGF-{beta}1 and cAMP generating compounds have significant effects on VEGF-C and VEGF-A synthesis, which appear dysregulated in lung fibroblasts from ex-smokers and patients with COPD. Increased VEGFR3 expression in the bronchial epithelium in lung tissue, and studies into their functional impact, warrants further investigations.

The prevalent transcriptional repressor NrdR binds to highly conserved prokaryotic sequences in the promoter regions of operons encoding the essential enzyme ribonucleotide reductase. The NrdR binding sites consist of two partially palindromic 16 bp sequences (NrdR boxes) separated by a 15-16 bp linker sequence. We have assessed the requirement of both boxes for binding, the propensity of different NrdRs to bind to heterologous binding sites, and that the linker sequence is only limited to length and not sequence conservation. As we have observed several deviations from the conserved sequences of the NrdR boxes, we here test the conservation requirements of individual basepairs in the NrdR boxes using a synthetic DNA fragment (Synt DNA) to which the NrdR proteins from the actinomycete Streptomyces coelicolor and the gammaproteobacterium Escherichia coli bind equally well as to their homologous binding sites. By introducing isolated mutations to Synt DNA and testing the binding capacity of NrdR from S. coelicolor and E. coli we expand our understanding of what criteria are needed to build a functional binding site for the NrdR repressor.

If youve ever complained about a species name thats a mouthful--say, the soldier fly Parastratiosphecomyia stratiosphecomyioides or the myxobacterium Myxococcus llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochensis--youre in very good company. But could the readability of binomial scientific names cause more than complaints? Could it influence how much species are studied and talked about? We examined a random sample of 3,019 species names spanning 29 phyla/divisions. We tested whether name length and reading difficulty are associated with species representation in the scientific literature (measured via literature mentions) and their visibility to the public (measured via Wikipedia pageviews). Both species name traits showed significant negative relationships with literature mentions and Wikipedia reads. Increasing name length from 10 to 30 characters is associated with a 66% decrease in expected mentions and a 65% decrease in Wikipedia reads, while shifting from the most to the least readable name in the dataset corresponds to 53% and 76% decreases. These patterns are consistent with something familiar: the fickleness of human attention, responding to features of the world that are far from rational. While creativity in naming is a cherished part of taxonomy, a touch of orthographic restraint may ultimately benefit both science and the species themselves--especially among understudied uncharismatic taxa.

Collagens are key components of the extracellular matrix (ECM) that play a crucial role in maintaining structure, strength, and function of the lungs. Fibrillar collagens are crosslinked by enzymes such as lysyl oxidases and transglutaminases and organized into networks by proteoglycans and glycoproteins. Collagens are the main load-bearing components and along with elastin may impart a non-linear strain hardening behavior to the lung. In disease, collagen crosslinking and organization can be disrupted, possibly due to abnormal levels of enzymes or ECM components. Few studies have examined collagen crosslinking and organization in healthy and diseased human lungs. In this study, alterations in collagen crosslinking and organization were investigated in human lung control, fibrotic and chronic obstructive pulmonary disease (COPD) tissue sections. Ultra-performance liquid chromatography and second harmonic generation microscopy measured pyridinoline crosslinks and the distribution of mature and immature collagens within the decellularized scaffolds, respectively. Fibrotic scaffolds had higher total collagen but less crosslinking per mole of collagen compared with COPD donors. Image analysis by second harmonic generation microscopy showed mature collagens populated airway or blood vessel walls in all three groups and in the parenchyma of fibrotic scaffolds. Immature collagens, on the other hand, were mainly localized to parenchymal regions in control and COPD scaffolds, with fewer immature collagens in fibrotic parenchyma. Additionally, quantification of the mature to immature collagen ratio in defined regions of control and diseased scaffolds showed increased organized collagen in fibrotic tissue. Our study shows that collagen crosslinking and organization are disrupted in fibrotic and COPD lungs and these changes may be compartment specific and can contribute to aberrant mechanical properties of diseased lungs. Our findings highlight that along with total collagen content, collagen crosslinking and organization are equally important while investigating collagen-mediated pathological changes in lung tissue. These changes may have implications for developing ECM-based therapeutics for patients with lung diseases.

Conflicting roles have been proposed for the E. coli protein RatA. Initially described as a ribosome targeting toxin, a later report pronounced it the bacterial homologue to the inner mitochondrial membrane protein Coq10. Coq10 proteins are conserved from prokaryotes to human and implicated to serve a lipid chaperone role in the biosynthesis of ubiquinone, a crucial electron carrier during aerobic respiration. We recently identified that the contradictory results published for RatA can be attributed to a mis-annotation of the gene in the reference genome. Here, we further elucidate the molecular function of RatA. We clarify that RatA is not a toxin but serves as a lipid shuttle for ubiquinone from its cytosolic biosynthesis complex to the inner membrane. Furthermore, we show that the loss of RatA results in an impaired, but not abolished electron transport chain and demonstrate broad metabolic adaptations of the cells as a consequence. Therefore, we propose to rename RatA to UbiM to reflect its function and to be in accordance with the naming convention of other ubiquinone biosynthesis proteins.

G protein-coupled receptors rely on dynamic conformational changes to coordinate G protein activation and recruitment of regulatory transducers such as G protein-coupled receptor kinases and {beta}-arrestins. The chemotactic receptor GPR183 has been implicated in a context-dependent role in hematological malignancies. Here, we investigated the impact of A338V mutation located within the C-terminal tail of GPR183. This mutation is associated with acute myeloid leukaemia. Using bioluminescence resonance energy transfer-based assays in HEK293A cells, we assessed receptor-proximal signaling events. The A338V variant displayed preserved agonist potency and comparable agonist-induced Gi activation relative to wild type, although constitutive activity towards Gi was modestly reduced. In contrast, recruitment of GRK2 and {beta}-arrestin2 was consistently impaired across multiple assay configurations. These differences were not attributable to altered receptor abundance, as the C-tail untagged mutant exhibited increased plasma membrane expression despite reduced regulatory transducer engagement. While intramolecular conformational biosensor measurements revealed subtle differences in global receptor conformation between WT and A338V, extensive molecular dynamics simulations supported the altered conformational sampling of the C-terminal tail in the A338V variant. Together, these data support a model in which the A338V substitution selectively alters C-terminal structural dynamics, impairing GRK2 and {beta}-arrestin2 recruitment while preserving G protein activation.

BackgroundTuberculosis (TB) is the second-leading cause of deaths from infectious agents and remains a global health threat. Ethionamide (ETH) is a prodrug used in regimens for multidrug-resistant TB, and, partly due to side effects that can lead to low treatment adhesion, resistance arises. Changes in EthA, the monooxygenase that activates ETH, are the main mechanism of resistance. Yet, of hundreds of EthA substitutions found in resistant isolates, only a handful have been annotated as resistance determinants. ResultsAn in silico analysis was carried out on a previously described panel of Mycobacterium tuberculosis clinical isolates for which genomes and ETH susceptibility testing results were available. EthA substitutions were mapped, revealing the existence of hotspots in its sequence. Visualization of the hotspots in the EthA structural model shows that they cluster in three regions, including ligand binding pockets. Models were built of twenty-three variants found in resistant isolates and changes in local configuration was mapped to identify investigate impact on ETH activation. Information from these models contributed to establishing five criteria for scoring whether substitutions are most likely to lead to resistance. Using these criteria, EthA D58G was selected and its expression is shown to increase growth in high ETH concentrations. ConclusionFunctionally relevant regions of EthA are revealed and point out priority substitutions for functional studies, enhancing identification and detection of substitutions not been previously associated with resistance.

Scientific supervision is central to the experience of early-career researchers (ECRs), yet its role in shaping wellbeing and retention remains underexamined from the ECR perspective. We analyzed 2,604 anonymous survey responses from predoctoral, postdoctoral and former researchers across 65 countries. Overall, 76% of respondents reported that their supervisors attitude had a moderate or severe impact on mental health. Although most entered academia for vocational reasons, negative experiences with supervisors were among the most frequently reported reasons for leaving among former researchers (48%), comparable to job insecurity and financial instability. Harm was most often associated with poor communication, disregard for wellbeing, micromanagement and competitiveness. In contrast, ECRs valued supportive rather than boss-like supervision, regular communication, realistic expectations and respect for personal time. These findings identify supervisory behavior as a major and modifiable determinant or ECRs wellbeing and retention, and highlight the need for stronger institutional accountability, mentor training and funding incentives that recognize mentorship as a core component of research culture.

Academic institutions privilege norms of continuous productivity and uninterrupted availability, creating conformity pressures that systematically disadvantage those who deviate from an implicit template of the ideal academic. This study explores how doctoral students and faculty in the health sciences perceive the reproduction of social homogeneity. Semi-structured interviews were conducted with nine participants at a German university hospital. Data were analysed using reflexive thematic analysis with extended idiographic engagement. Participants perceived homogeneity as reproduced through external exclusion, enacted by others through networks, normative expectations, or institutional arrangements, and self-exclusion, whereby individuals withdrew, reduced visibility, or reshaped identity in anticipation of exclusion ( anticipatory compliance). Across both processes, the tacit norm of the ideal academic organised access and belonging. Supportive supervision and visible role models were perceived as partial buffers but did not structurally alter underlying norms. Interpreted through the social identity threat framework, these findings are consistent with a self-reinforcing cycle: structural homogeneity may generate identity-threatening environments that activate concealment and withdrawal, concentrating homogeneity further. These findings suggest that achieving substantive inclusion requires challenging the structural conditions that naturalise presence, mobility, and availability as measures of academic success.

BackgroundCalcific aortic valve disease (CAVD) is the most common valvular heart disease in developed countries, yet no pharmacological therapy is available to slow or halt its progression. CAVD is driven by progressive calcification of aortic valve leaflets, in which myeloid cells play a central role. While macrophages have been implicated in CAVD pathogenesis, the contribution of their precursors, monocytes, remains poorly understood. We hypothesized that circulating monocytes acquire a pro-calcific and pro-inflammatory phenotype contributing to valve remodelling and CAVD progression. MethodsWe profiled circulating CD14+ monocytes from healthy volunteers (Vol), patients with CAVD, and without CAVD (NCAVD). Peripheral blood mononuclear cells (PBMCs) were isolated, and monocyte subpopulations were phenotyped by flow cytometry. Transcriptome profiling by RNA sequencing identified disease-associated gene signatures, which were validated by RT-qPCR. The CD14+ monocyte secretome was analysed using multiplex assays. Functional ability of CAVD-derived CD14+ monocytes to induce myofibroblastic transdifferentiation (MT) and osteoblastic differentiation (OD) of human valvular interstitial cells (VICS) was evaluated by immunocytochemistry and quantitative o-cresolphthalein complexone assays. ResultsIn PBMCs, CAVD monocytes displayed a subpopulation shift, with an increased proportion of CD14CD16- classical monocytes and a reduced CD14CD16 non-classical monocyte levels. In CD14+ monocytes, transcriptomic analysis revealed upregulation of inflammation-related (PDK4) and calcification-related (ATP2B1) genes, alongside downregulation of immunomodulatory genes (DDR1, IKBKE). Secretome analysis showed reduced production of immunomodulatory and anti-osteoblastogenic cytokines (IL-4, CCL3) while promoting gene expression of factors promoting MT and OD in VICS. These alterations were associated with a marked monocyte-induced increase in SMA and OPN expression in VICS and a two-fold increase in calcification. ConclusionWe demonstrate for the first time that circulating monocytes from patients with CAVD exhibit enhanced pro-inflammatory and pro-calcific properties that may contribute to CAVD progression. Additionally, we identify dysregulated gene sets within these monocytes that represent potential novel therapeutic targets for CAVD.

Age-related macular degeneration (AMD) is a progressive complex eye disease and one of the leading causes of blindness. AMD progression is marked by molecular changes in the retinal pigmented epithelium (RPE) which include increased reactive oxygen species (ROS) accumulation, mitochondrial dysfunction - eventually leading to dysfunctional RPE. Mitophagy regulator, Pink1, is reduced in the RPE of AMD patients and Pink1 loss leads to a shift from mitochondrial respiration to glycolysis. Serine is a non-essential amino acid which is de novo synthesized from glycolytic intermediate 3-PG via the rate limiting enzyme PHGDH. Serine is tightly integrated into anabolic processes like glutathione (GSH) cycling, maintaining NADH/NADPH pools leading to changes in AMPK signaling. Here, we show that Pink1 loss leads to a reduction in PHGDH and serine levels in the RPE leading to impaired mitochondrial structure and function, increased ROS mediated damage, increased inflammation, and hampered retinal function. Serine supplementation rescued ROS accumulation, balanced GSH abundance, and increased retinal function. Overall, our study highlights the potential of dietary serine in ROS management in AMD.

The preprint ecosystem has expanded rapidly over the past decade, fundamentally altering science communication. Yet, the scholarly communitys attitudes toward this shift remain underexplored. Through a large-scale survey of US and Canadian biomedical scholars, we provide a comprehensive analysis of preprint utilization, perceived impact, and integration into academic credit systems. We find robust engagement across reading, citing, and submitting preprints; however, this activity is driven primarily by a desire for rapid dissemination rather than a foundational commitment to open science. Furthermore, while preprints are valued as networking assets, perceived career penalties during formal academic evaluations stifle broader cultural adoption. Crucially, to navigate the absence of formal peer review, scholars report a heavy reliance on author reputation as a primary heuristic to evaluate a preprints credibility and guide their reading and citation decisions. Notably, despite acknowledging preprints role in accelerating knowledge sharing, scholars express significant concerns regarding fraud and misinformation, particularly amid declining public trust in science and emerging threats to scientific integrity from artificial intelligence. To resolve these tensions, the preprint ecosystem must evolve beyond prioritizing speed to foster genuine academic dialogue. Simultaneously, evaluation frameworks must adapt to the realities of preprinting, and innovative quality-control mechanisms are urgently needed to balance rapid dissemination with rigorous scientific integrity.

Stress Granules (SGs) are cytoplasmic biomolecular condensates that form in response to a variety of stress conditions, though their function remains unclear. "Canonical" SGs - caused by stressors like sodium arsenite - are dynamic and cytoprotective, allowing cells to evade cell death during periods of stress. Ultraviolet (UV) irradiation is known to elicit a "non-canonical" SG subtype, lacking canonical SG components such as eukaryotic initiation factor 3 and polyadenylated mRNAs. The exact function of UV SGs, and the mechanisms driving their formation, remain unknown. Here we report the findings of a comparative analysis of UVA, UVB and UVC exposures on SG formation in three cell types: osteosarcoma (U2OS), keratinocytes (HaCaT), and mouse embryonic fibroblasts (MEF). We observed that SG formation in response to UV is highly cell type dependent. UVB and UVC induce robust SG formation in U2OS cells. However, only UVC exposure induced modest SG formation in MEFs, and none of the wavelengths caused SGs in HaCaT. While UVC-induced SGs in U2OS cells appear to be cell cycle dependent and specific to G1, UVB induced SG formation regardless of cell cycle stage. We tested the hypothesis that oxidative stress triggered by UV may be driving UV SG formation, and that keratin may buffer this effect, by overexpressing keratin in U2OS. Interestingly, we found that keratin and antioxidant treatment efficiently suppressed arsenite-induced SGs but had no effect on UV SGs. Our work confirms that UV SG formation is cell type specific and is not driven by oxidative stress.

Pantothenamides (PanAms) comprise a promising class of antimalarial compounds that kill asexual blood-stage Plasmodium falciparum parasites and block transmission. Intriguingly, the most advanced PanAm in drug development, MMV693183, is approximately 100 times more potent against female gametocytes than males. We hypothesized that this specificity is explained by a difference in PanAm uptake, which we studied using a PanAm-based photoaffinity labelling (PAL) probe. We successfully synthesized a probe that competed with MMV693183 in drug sensitivity assays, while the probe did not display high potency by itself. We observed no significant difference in median fluorophore-labelled probe signal intensity between male and female gametocytes, although there might be a difference in subcellular localization of the probe between the sexes. By combining PAL with affinity purification and mass spectrometry, we were not able to identify novel candidate PanAm transporters. We conclude that PAL provides evidence that differences in PanAm uptake do not underly differences in PanAm sensitivity between the gametocyte sexes.

Accurately modeling antibody-antigen interactions requires distinguishing intrinsic binding affinity ("protein-interaction") from protein biophysical properties ("protein-quality"), including folding, stability, and expression. However, high-throughput mutational measurements commonly used to train and benchmark computational models often conflate these effects, obscuring the true determinants of molecular recognition. Here, we present an experimental and analytical framework to disentangle protein-interaction effects from protein-quality effects in single-domain antibody (VHH)-antigen binding. Using a large-scale deep mutational scanning (DMS) dataset spanning four VHH-antigen complexes, with single and double mutations in both partners, we introduce control binders to quantify protein-quality changes independently of protein-interaction. This enables decomposition of experimentally measured affinity into protein-interaction and protein-quality components at scale. Leveraging the disentangled dataset, we evaluated state-of-the-art structure- and sequence-based models for protein-quality and protein-interaction prediction and show that their performance largely reflects protein-quality rather than protein-interaction effects. Our results highlight a major confounder in current datasets and suggest that accounting for protein-quality will be essential for training next-generation affinity-prediction models. Nomenclature Antibody related termsO_LIPrimary VHH: The VHH of a VHH-antigen complex for which the paratope and the epitope weremutated. C_LIO_LIControl VHH: A second VHH that binds to the same antigen as the primary VHH but has non-overlapping epitope positions and therefore does not bind to any of the mutated antigen positions. C_LI Affinity-related termsO_LIReal Affinity: "The strength of the interaction between two [...] molecules that bind reversibly (interact)" 1. In the context of antibody-antigen binding, it quantifies interactions between active proteins (which are expressed and correctly folded 2 and are therefore functionally and biologically active (see below). It is commonly quantified by the equilibrium dissociation constant, KD. C_LIO_LIObserved affinity ({degrees}KD): The interaction strength experimentally measured between two molecules. Unlike real affinity, this value is confounded by the biophysical properties of the individual binding partners, specifically their folding, stability, and expression levels. Consequently, the observed affinity often differs from the real/intrinsic affinity if a significant fraction of the protein population is inactive 3. NOTE: Unless otherwise specified, {degrees}KD is reported in - log10 space. For example, a {degrees}KD of -9 corresponds to 10-9M or 1nM. C_LIO_LIChange in observed affinity ({Delta}{degrees}KD): The shift in the observed affinity between two proteins upon mutation, reported as the log10-transformed fold change. A value of 1 reflects a 10-fold difference, a value of 2 a 100-fold difference, etc. This aggregate change resolves into two distinct biophysical components 2, 4: O_LIProtein-interaction change: The change in the intrinsic thermodynamic affinity between the two binding partners, each in its active state (i.e., the specific change in interface Gibbs free energy because both enthalpy and entropy are considered). C_LIO_LIProtein-quality change: The change in the fraction of the mutated protein population that is biologically active - meaning it is expressed, correctly folded, and stable 2, 5. O_LIFolding: The process that guides the polypeptide chain toward its native conformation, which is a prerequisite for forming a functional binding site. C_LIO_LIStability: The thermodynamic capacity to maintain the folded structure over time and under physiological conditions. Stability (decrease in Gibbs free energy from the unfolded to the folded state) ensures the binding interface remains intact and prevents competing processes such as aggregation 6. C_LIO_LIExpression: The steady-state abundance of the protein. This is largely dependent on proper folding and stability, as cellular quality control mechanisms degrade proteins that fail to fold or remain stable at functional concentrations. C_LI C_LI C_LIO_LIChange in relative affinity ({Delta}{Delta}{degrees}KD): the difference between the {Delta}{degrees}KD of the primary VHH compared to the control VHH for a given epitope mutation. C_LI Model-related termsO_LIESM-IF1 sc: Single-chain (sc) structure-conditioned inverse folding model (ESM-IF1), using the isolated monomer structure of the mutated protein: either the VHH or the antigen 7. C_LIO_LIESM-IF1 mc: Multi-chain (mc) structure-conditioned model (ESM-IF1), using the full complex structure (both antibody and antigen) 7. C_LIO_LIStability prediction score: Score that represents the predicted change in stability based on a single mutation, normally represented as {Delta}{Delta}G. C_LI