Reaction Mechanism of Pyridoxal 5′-Phosphate Synthase
نویسندگان
چکیده
منابع مشابه
Reaction mechanism of pyridoxal 5'-phosphate synthase. Detection of an enzyme-bound chromophoric intermediate.
Vitamin B6 is an essential metabolite in all organisms. De novo synthesis of the vitamin can occur through either of two mutually exclusive pathways referred to as deoxyxylulose 5-phosphate-dependent and deoxyxylulose 5-phosphate-independent. The latter pathway has only recently been discovered and is distinguished by the presence of two genes, Pdx1 and Pdx2, encoding the synthase and glutamina...
متن کاملMode of binding of pyridoxal phosphate to 5-aminolevulinate synthase.
5-Aminolevulinate synthase of Rhodopseudomonas spheroides interacts with its cofactor, pyridoxal phosphate, and shows an absorption maximum at 430 nm with a probable shoulder at 320--330 nm. The enzyme-PLP complex absorbing at 430 nm is the predominant species at pH 7.2 and can be reduced by NaBH4 at neutral pH with a spectral shift of the absorption maximum to 325 nm. These data suggests the f...
متن کاملBinding of Pyridoxal 5'-Phosphate
1. The a and ,B subforms of aspartate aminotransferase were purified from pig heart. 2. The a subform contained 2mol of pyridoxal 5'-phosphate. The apo-(a subform) could be fully reactived by combination with 2mol of cofactor. 3. The protein fluorescence of the apo(a subform) decreased non-linearly with increase in enzyme activity and concentration of bound cofactor. 4. It is concluded that the...
متن کاملFunction of the phosphate group of pyridoxal 5'-phosphate in the glycogen phosphorylase reaction.
To understand the catalytic mechanism of glycogen phosphorylase (EC 2.4.1.1), pyridoxal(5')phospho(1)-beta-D-glucose was synthesized and examined as a hypothetical intermediate in the catalysis. Pyridoxal phosphoglucose bound stoichiometrically to the cofactor site of rabbit muscle phosphorylase b in a similar mode of binding to the natural cofactor, pyridoxal 5'-phosphate. The rate of binding ...
متن کاملTransfer of pyridoxal 5'-phosphate from albumin-pyridoxal 5'-phosphate complex to apo-aspartate aminotransferase.
Pyridoxal 5•L-phosphate (PLP) is known to combine with bovine serum albumin to form a(1:1) complex which scarcely dissociates, even when subjected to intensive dialysis. When this complex was incubated with apo-aspartate aminotransferase (apoGOT) for an appropriate time and the preincubated mixture then submitted to the usual GOT assay, the appearance of GOT activity was obviously confirmed, in...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 2007
ISSN: 0021-9258
DOI: 10.1074/jbc.m610614200