The inactivation of the acyl phosphatase activity catalyzed by the sulfenic acid form of glyceraldehyde 3-phosphate dehydrogenase by dimedone and olefins.

摘要: Abstract Treatment of the sulfenic acid form glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12) with a 2-fold molar excess dimedone over concentration enzyme subunit completely inactivates acyl phosphatase reaction catalyzed by oxidized enzyme. The activity reduced is not reactivated when dimedone-inactivated treated dithiothreitol. When inactivated [14C]dimedone ∼1 µg atom 14C incorporated per µeq which removed gel filtration on Sephadex G-25. A 14C-labeled peptide from tryptic digest was has been isolated in pure and subjected to sequence analysis. This analysis shown that forms thioether derivative Cys-149 reacting at active site phosphatase. unaffected radioactivity into protein. pig muscle also 25 mm 3-cyclohexene-1-carboxylate pH 5.1 presence 0.1 m (NH4)2SO4 other salts. dithiothreitol does reactivate indicates treatment olefin leads covalent modification Cys-149, catalytically essentially sulfhydryl group for dehydrogenase. under identical conditions no effect activity. 5.0 dihydropyran 7.6 30 tetrahydrophthalimide 6.0. these reagents Under used inactivate phosphatase, two olefins do native added it directly. Amino contains after suggests an adduct between formed during inactivation.