Mechanistic study of protein phosphatase-1 (PP1), a catalytically promiscuous enzyme

C McWhirter, EA Lund, EA Tanifum…

Index: McWhirter, Claire; Lund, Elizabeth A.; Tanifum, Eric A.; Feng, Guoqiang; Sheikh, Qaiser I.; Hengge, Alvan C.; Williams, Nicholas H. Journal of the American Chemical Society, 2008 , vol. 130, # 41 p. 13673 - 13682

Full Text: HTML

Citation Number: 34

Abstract

The reaction catalyzed by the protein phosphatase-1 (PP1) has been examined by linear free energy relationships and kinetic isotope effects. With the substrate 4-nitrophenyl phosphate (4NPP), the reaction exhibits a bell-shaped pH-rate profile for k cat/KM indicative of catalysis by both acidic and basic residues, with kinetic p K a values of 6.0 and 7.2. The enzymatic hydrolysis of a series of aryl monoester substrates yields a Brønsted βlg of− ...