Spectroscopic signatures of the T to R conformational transition in the insulin hexamer

摘要: The cobalt(II)-substituted human insulin hexamer has been shown to undergo the phenol-induced T6 R6 structural transition in solution. accompanying octahedral tetrahedral change ligand field geometry of cobalt ions results dramatic changes visible region electronic spectrum and thus represents a useful spectroscopic method for studying T R transition. Changes Co2+ spectral envelope show that aqua associated with each center can be replaced by SCN-, CN-, OCN-, N3-, Cl-, NO2-. 19F NMR experiments binding m-trifluorocresol stabilizes state zinc insulin. chemical shift line broadening CF3 singlet, which occur due binding, provide probe Due appearance new resonances aromatic region, 500 MHz 1H is readily distinguishable from form. studies phenol induces transition, both (GlnB13)6(Zn2+)2 metal-free GlnB13 species; we conclude metal not prerequisite formation this mutant.