منابع مشابه
Reversible stepwise mechanism involving a carbanion intermediate in the elimination of ammonia from L-histidine catalyzed by histidine ammonia-lyase.
L-Histidine labeled with deuterium at the C-5' position of the imidazole ring, L-[5'-2H]histidine (His-5'-D), was used as a probe for investigating a stepwise reversible mechanism via a carbanion intermediate in the elimination of ammonia catalyzed by histidine ammonia-lyase (EC 4.3.1.3). The labeled L-histidine (His-5'-D) (2.45 mM) was incubated with histidine ammonia-lyase (200 units) from Ps...
متن کاملThe mechanism of action of phenylalanine ammonia-lyase: the role of prosthetic dehydroalanine.
Phenylalanine ammonia-lyase (EC 4.3.1.5) from parsley is posttranslationally modified by dehydrating its Ser-202 to the catalytically essential dehydroalanine prosthetic group. The codon of Ser-202 was changed to those of alanine and threonine by site-directed mutagenesis. These mutants and the recombinant wild-type enzyme, after treatment with sodium borohydride, were virtually inactive with L...
متن کاملYeast Phenylalanine Ammonia-lyase
I?henyialanine ammonia-lyase from the yeast Rhodotorula gluiinis was purified by salt fractionations and Sephadex chromatography. Density gradient centrifugation and Sephadex chromatography indicated its molecular weight to be about 275,000. Enzymatic deamination of several ring-substituted phenylalanine analogues and n-phenylalanine was studied. While cinnamic acid, a product of deamination, a...
متن کاملIn vivo regulation of histidine ammonia-lyase activity from Streptomyces griseus.
The enzyme histidine ammonia-lyase (histidase) is required for growth of Streptomyces griseus on L-histidine as the sole source of nitrogen. Histidase was induced by the inclusion of histidine in the medium, regardless of the presence of other carbon and nitrogen sources. Histidase activity was increased by a shift of culture incubation temperature from 30 to 37 degrees C. Conversely, upon indu...
متن کاملInhibition of histidine ammonia lyase by 8-methoxypsoralen and psoralen-oxidized photoproducts.
The effect of 8-methoxypsoralen-UVA therapy on the catalysis of histidine to trans-urocanic acid by histidine ammonia lyase (HAL, EC 4.3.1.3) was examined using an enzymatic assay from Sigma-Aldrich where the growth of the trans-urocanic acid peak at 277 nm was monitored. A Rayonet Photochemical Mini Reactor (Model RMR-600) equipped with eight, 3500 Å light sources and a custom UVA filter (Mode...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1969
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)63498-2