Interaction studies of Gut metabolite Trimethylene amine Oxide with Bovine Serum Albumin through Spectroscopic, DFT and Molecular Docking Approach

Trimethyleneamine N-oxide (TMAO); a gut microbiota derived metabolite has been involved in human health and diseases. It is enhanced by insulin resistivity and linked with various metabolic syndromes in human being such as renal, neuro-degenerative, and cardiovascular diseases. The primary mechanism through which TMAOs promotes disease is not clear yet. TMAO with MW= 75.11 g/mol is a small biomolecule hence, it becomes crucial to develop the conjugate of TMAO with BSA for aptamer synthesis. The binding interactions among TMAO and BSA were investigated using spectroscopic methods like UV-Vis, photoluminescence, Fourier transform infrared and circular dichroism. Hydrophilicity/Hydrophobicity of the conjugate was monitored by using contact angle ([O]) measurement. Sodium dodecyl sulphate polyacryl amide gel electrophoresis (SDS-PAGE) confirmed the different ratio of conjugate formation with the help of band size. This interaction study reveals that TMAO bind with BSA on two sites and with high affinity on one site. Docking studies also showed TMAO is involved in non-covalent interaction with bovine serum albumin forming stable docking complex with binding score of -3.6 kcal/mol obtained from the docking simulation. TMAO is involved in interaction with BSA via amino acid residues forming the stable docking complex through hydrogen bond and electrostatic interaction. This kind of interaction study may be helpful in making strategies to break the conjugation between serum albumin and uremic toxin and pave the way for the treatment for CKD and other diseases wherein TMAO is implicated. Also, conjugation of TMAO and BSA studied here may also serve as premise to develop aptamers for the detection of TMAO in the body fluids.