Stability and activity modulation of chymotrypsins in AOT reversed micelles by protein-interface interaction - Interaction of alpha-chymotrypsin with a negative interface leads to a cooperative breakage of a salt bridge that keeps the catalytic active conformation (IIe(16)-Asp(194))

Almeida FCL; Valente AP; Chaimovich H

Biotechnology and Bioengineering, Vol.59, No.3, 360-363, 1998

DOI10.1002/(SICI)1097-0290(19980805)59:3<360::AID-BIT12>3.0.CO;2-I Export Citation

Stability and activity modulation of chymotrypsins in AOT reversed micelles by protein-interface interaction - Interaction of alpha-chymotrypsin with a negative interface leads to a cooperative breakage of a salt bridge that keeps the catalytic active conformation (IIe(16)-Asp(194))

Almeida FCL, Valente AP, Chaimovich H

The stability of alpha-chymotrypsin and delta-chymotrypsin was studied in reversed micelles of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in isooctane, alpha-Chymotrypsin is inactivated at the interface and at the water pool, while delta-chymotrypsin is inactivated only at the water pool. The mechanism of inactivation at the interface is related to the interaction of N-terminal group alanine 149 (absent in delta-chymotrypsin) with the negative interface. The dependence of enzyme activity on water content of these two enzymes in reversed micelles of AOT is also related with the interface interaction, since delta-chymotrypsin does not have a bell-shaped curve as observed for alpha-chymotrypsin.

Keywords:DELTA-CHYMOTRYPSIN;ORGANIC-SOLVENTS