Enzyme structure and dynamics affect hydrogen tunneling: the impact of a remote side chain (I553) in soybean lipoxygenase-1.

ABSTRACT: This study examines the impact of a series of mutations at position 553 on the kinetic and structural properties of soybean lipoxygenase-1 (SLO-1). The previously uncharacterized mutants reported herein are I553L, I553V, and I553G. High-resolution x-ray studies of these mutants, together with the earlier studied I553A, show almost no structural change in relation to the WT-enzyme. By contrast, a progression in kinetic behavior occurs in which the decrease in the size of the side chain at position 553 leads to an increased importance of donor-acceptor distance sampling in the course of the hydrogen transfer process. These dynamical changes in behavior are interpreted in the context of two general classes of protein motions, preorganization and reorganization, with the latter including the d

SUBMITTER: Meyer MP 

PROVIDER: S-EPMC2234106 | biostudies-literature | 2008 Jan

REPOSITORIES: biostudies-literature