Pyridoxal 5'-phosphate-dependent histidine decarboxylase. Mechanism of inactivation by alpha-fluoromethylhistidine.
نویسندگان
چکیده
منابع مشابه
Pyridoxal 5”Phosphate-dependent Histidine Decarboxylase
Pyridoxal phosphate-dependent histidine decarboxylase from Morganella morganii AM-15 was inactivated by (a-a-fluoromethylhistidine by a pseudo firstorder reaction, with KI and kinact values of 0 . 1 mM and 32.2 min-l, respectively, and was most efficient at pH 6.5-7.0. Both L-histidine and the competitive inhibitor, L-histidine methyl ester, protected against inactivation. The apoenzyme was not...
متن کاملMOLECULAR MODELING AND NMR STUDY OF HISTDINIE AND ITS ANALOGUES AS , PYRIDOXAL 5 '-PHOSPHATE DEPENDENT HISTIDINE DECARBOXYLASE INHIBITORS
Molecular modeling analysis of charge density and heat of fornation by PM3 method as well as C, H NMR and 2D-NMR measurements of histidine (substrate) and some of its derivatives as histidine decarboxylase inhibitors were performed. It was established that the atom, usually nitrogen, which forms internal aldimine with pyridoxal5 -phosphate (PLP), (coenzyme), has negative and almost equal ...
متن کاملPurification and properties of a pyridoxal 5'-phosphate-dependent histidine decarboxylase from Morganella morganii AM-15.
A pyridoxal 5'-phosphate-dependent histidine decarboxylase from Morganella morganii AM-15 was purified to homogeneity. The enzyme is a tetramer (Mr 170,000) of identical subunits and binds 4 pyridoxal-P/tetramer; it is resolved by dialysis against cysteine at pH 6.8. Between pH 6.2 and 8.8, the holoenzyme shows pH-independent absorbance maxima at 333 and 416 nm. Vmax/Km is highest at pH 6.5; th...
متن کاملmolecular modeling and nmr study of histdinie and its analogues as , pyridoxal 5 '-phosphate dependent histidine decarboxylase inhibitors
molecular modeling analysis of charge density and heat of fornation by pm3 method as well as c, h nmr and 2d-nmr measurements of histidine (substrate) and some of its derivatives as histidine decarboxylase inhibitors were performed. it was established that the atom, usually nitrogen, which forms internal aldimine with pyridoxal5 -phosphate (plp), (coenzyme), has negative and almost equal charge...
متن کاملpH studies on the mechanism of the pyridoxal phosphate-dependent dialkylglycine decarboxylase.
The pH dependence of the steady-state kinetic parameters for the dialkylglycine decarboxylase-catalyzed decarboxylation-dependent transamination between 2-aminoisobutyrate (AIB) and pyruvate is presented. The pH dependence of methylation and DTNB modification reactions, and spectroscopic properties, is used to augment the assignment of the kinetic pKa's to specific ionizations. The coincidence ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1990
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(19)39201-4