Analysis of conformational changes during activation of protein kinase Pak2 by amide hydrogen/deuterium exchange.

ABSTRACT: During apoptotic stress, protein kinase Pak2 is cleaved by caspase 3 to form a heterotetramer that is constitutively activated following autophosphorylation. The active protein kinase migrates slightly slower than the inactive holoenzyme when analyzed by gel filtration, suggesting an expanded conformation. Activation of Pak2 comprises a series of structural changes resulting from caspase cleavage, ATP binding, and autophosphorylation of Pak2. Changes at each step were individually analyzed by amide hydrogen/deuterium exchange coupled with mass spectrometry and compared with inactive Pak2. The auto-inhibited form was shown to bind ATP in the active site, with minor changes in the glycine loop and the autoinhibitory domain (AID). Caspase cleavage produced significant changes in solvent acces

SUBMITTER: Hsu YH 

PROVIDER: S-EPMC2605980 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature