Kinetic Studies on Tyrosine-α-ketoglutarate Transaminase
نویسندگان
چکیده
منابع مشابه
Regulation of tyrosine- -ketoglutarate transaminase in rat liver.
The role of the pancreatic hormones, insulin and glucagon, in the regulation of hepatic tyrosine transaminase (L-tyrosine : Z-oxoglutarate aminotransferase, EC 2.6.1.5) was studied in adrenalectomized rats. Each of these hormones initiated a rapid but limited increase in the enzyme level, which reached a maximum after 2.5 to 3 hours. The optimal doses of insulin and glucagon per 100 g of body w...
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The role of pyridoxine and its coenzymically active derivatives in determining the stability of rat liver tyrosine cy-ketoglutarate transaminase in vifro and in vivo was studied. Incubation of crude or purified holoenzyme preparations with cysteine and other amino acids causes removal of the coenzyme and subsequent inactivation of the inherently unstable apoenzyme; under these conditions the re...
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With the discovery that pyridoxal phosphate and pyridoxamine phosphate were cofactors for enzymatic transamination, it was proposed that the reaction was biphasic, involving first an amino group transfer from the amino acid substrate to enzymebound pyridoxal phosphate, followed by a transfer of the amino group to the keto acid substrate (for review, see (1)). With the availability of a highly p...
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The administration of t ryptophan or cortisone to rats bearing the Morris 5123 Hepatoma resulted in significant increases in t ryptophan pyrrolase activity in the host liver but in no change in the low tryptophan pyrrolase activity of the neoplasm. The repressed level of this enzyme in the neoplasm was not a result of the lack or excess of cofactors or enzymes necessary for the assay procedure ...
متن کاملSpecificity of the Adaptive Response of Tyrosine-a-ketoglutarate Transaminase in the Rat*
The tyrosine-cr-ketoglutarate transaminase of liver was increased several-fold 5 hours after a single injection of hydrocortisone was given to either intact or adrenalectomized rats. In contrast, the injection of a substrate of this enzyme, n-tyrosine, increased the enzyme level in only the intact animals as opposed to the adrenalectomized ones, unless hydrocortisone was also administered. Tyro...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1963
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)51800-7