Evolution of Negative Cooperativity in Glutathione Transferase Enabled Preservation of Enzyme Function.

ABSTRACT: Negative cooperativity in enzyme reactions, in which the first event makes subsequent events less favorable, is sometimes well understood at the molecular level, but its physiological role has often been obscure. Negative cooperativity occurs in human glutathione transferase (GST) GSTP1-1 when it binds and neutralizes a toxic nitric oxide adduct, the dinitrosyl-diglutathionyl iron complex (DNDGIC). However, the generality of this behavior across the divergent GST family and its evolutionary significance were unclear. To investigate, we studied 16 different GSTs, revealing that negative cooperativity is present only in more recently evolved GSTs, indicating evolutionary drift in this direction. In some variants, Hill coefficients were close to 0.5, the highest degree of negative cooperativi

SUBMITTER: Bocedi A 

PROVIDER: S-EPMC5207182 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature