Kinetic correlations between the XXXX bond reduction and the induced conformational change of proteins.

@entity16958 @entity2569 @entity9232 @entity2097 @entity5828 @entity1520 @entity1460 @entity14617 @entity291
Kinetic correlations between the @entity1520 bond reduction in excess @entity16958 and the induced conformational change were studied on two proteins, @entity291 @entity14617 and @entity1460 @entity9232 , at 25 degrees C and pH 8.0-8.5 by measuring the absorbance of oxidized @entity16958 at 310 nm and the ellipticity at 270 nm, respectively. With @entity14617 , in the absence of @entity2097 (Gdn x @entity5828 ) or in dilute Gdn x @entity5828 , the kinetics for the bond reduction and the conformational change were both of a biphasic type. The fast phase was complete within a few seconds and was associated with the reduction of some of the @entity1520 bonds and with almost complete loss of the tertiary structure. The slow phase was associated with the reduction of other @entity1520 bonds. In concentrated Gdn x @entity5828 , the kinetics of both processes were observed as a single phase, the rate of which was similar to that of the slow phase in the absence of Gdn x @entity5828 or in dilute Gdn x @entity5828 . In all cases studied, the rate of the bond reduction was similar to that of the conformational change induced. By correcting the change in absorbance at 310 nm to a contribution from the protein due to the conformational change, the number of bonds which are reduced in the fast phase in the absence of Gdn x @entity5828 was determined to be 1.0-1.1. It was shown, taking observations of others and theoretical results into account, that the bond reduced in the fast phase might be the one between @entity2569 6 and @entity2569 120. On the other hand, on of two bonds of @entity1460 @entity9232 in the native form was reduced in the fast phase without any loss of the tertiary structure, and the other was reduced in the slow phase. Considering the results of other researchers, it was concluded that the bond reduced in the fast phase of the inhibitor is a 136-145 bond.
