02685nas a2200229   4500008004100000022001400041245016600055210006900221260000800290300001600298490000600314520183500320100001802155700002402173700002002197700002302217700002002240700002002260700002002280700002502300856013002325       2022                        eng d  a2470-134300aInvestigation of the captopril-insulin interaction by mass spectrometry and computational approaches reveals that captopril induces structural changes in insulin0 aInvestigation of the captoprilinsulin interaction by mass spectr  cJUL  a23115-231260 v73 a<p>
	ABSTRACT: Post-translational modifications remarkably regulate proteins' biological function. Small molecules such as reactive thiols, metabolites, and drugs may covalently modify the proteins and cause structural changes. This study reports the covalent modification and noncovalent interaction of insulin and captopril, an FDA-approved antihypertensive drug, through mass spectrometric and computation-based approaches. Mass spectrometric analysis shows that captopril modifies intact insulin, reduces it into its ``A'' and ``B'' chains, and covalently modifies them by forming adducts. Since captopril has a reactive thiol group, it might reduce the insulin dimer or modify it by reacting with cysteine residues. This was proven with dithiothreitol treatment, which reduced the abundance of captopril adducts of insulin A and B chains and intact Insulin. Liquid chromatography tandem mass spectrometric analysis identified the modification of a total of four cysteine residues, two in each of the A and B chains of insulin. These modifications were identified to be Cys6 and Cys7 of the A chain and Cys7 and Cys19 of the B chain. Mass spectrometric analysis indicated that captopril may simultaneously modify the cysteine residues of intact insulin or its subunits A and B chains. Biophysical studies involving light scattering and thioflavin T assay suggested that the binding of captopril to the protein leads to the formation of aggregates. Docking and molecular dynamics studies provided insights into the noncovalent interactions and associated structural changes in insulin. This work is a maiden attempt to understand the detailed molecular interactions between captopril and insulin. These findings suggest that further investigations are required to understand the long-term effect of drugs like captopril.</p>
1 aGhosh, Amrita1 aPawar, Aiswarya, B.1 aChirmade, Tejas1 aJathar, Swaraj, M.1 aBhambure, Rahul1 aSengupta, Durba1 aGiri, Ashok, P.1 aKulkarni, Mahesh, J.  uhttps://library.ncl.res.in/content/investigation-captopril-insulin-interaction-mass-spectrometry-and-computational-approaches