A polarographic study on pyridoxal 5′-phosphate binding in glycogen phosphorylaseb
نویسندگان
چکیده
منابع مشابه
Binding 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 کاملBinding of pyridoxal 5-phosphate to cystathionase.
The binding of pyridoxal 5-phosphate to the apoprotein of the enzyme cystathionase from rat liver was investigated by two independent methods, absorption and fluorescence spectroscopy. The increase in absorbance at 525 nm associated with Schiff’s base formation was used to investigate the binding of pyridoxal-5-P at a protein concentration of 1 X 10e5 M. A model based on two classes of independ...
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 کاملPyridoxal 5′-Phosphate Is a Slow Tight Binding Inhibitor of E. coli Pyridoxal Kinase
Pyridoxal 5'-phosphate (PLP) is a cofactor for dozens of B(6) requiring enzymes. PLP reacts with apo-B(6) enzymes by forming an aldimine linkage with the ε-amino group of an active site lysine residue, thus yielding the catalytically active holo-B(6) enzyme. During protein turnover, the PLP is salvaged by first converting it to pyridoxal by a phosphatase and then back to PLP by pyridoxal kinase...
متن کاملLocation of pyridoxal phosphate in glycogen phosphorylase a.
The pyridoxal 5'-phosphate cofactor of glycogen phosphorylase a (1,4-alpha-D-glucan:orthophosphate alpha-glucosyltransferase, EC2.4.1.1.) has been positioned on the protomer with x-ray diffraction data, chemical markers, and sequence information. The electron density was computed from 3.0-A resolution phases calculated from four heavy-atom derivatives. The cofactor is buried inside the protomer...
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: FEBS Letters
سال: 1973
ISSN: 0014-5793
DOI: 10.1016/0014-5793(73)80012-2