Paired Spectroscopic and Crystallographic Studies of Proteases.

ABSTRACT: The active sites of subtilisin and trypsin have been studied by paired IR spectroscopic and X-ray crystallographic studies. The active site serines of the proteases were reacted with 4-cyanobenzenesulfonyl fluoride (CBSF), an inhibitor that contains a nitrile vibrational reporter. The nitrile stretch vibration of the water-soluble inhibitor model, potassium 4-cyanobenzenesulfonate (KCBSO), and the inhibitor were calibrated by IR solvent studies in H₂O/DMSO and the frequency-temperature line-slope (FTLS) method in H₂O and THF. The inhibitor complexes were examined by FTLS and the slopes of the best fit lines for subtilisin-CBS and trypsin-CBS in aqueous buffer were both measured to be -3.5×10^-2 cm^-1/°C. These slopes were intermediate in value betw

SUBMITTER: Luo M 

PROVIDER: S-EPMC8221577 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature