title: Further evaluation of cofactor as a turnover label for glycogen phosphorylase.
abstract: 1. The cofactor of glycogen phosphorylase, pyridoxal phosphate (PLP), is stably associated with the enzyme and has been used as a label in the determination of the turnover of the skeletal muscle enzyme in vivo. 2. Mice were injected with radiolabelled pyridoxine that was subsequently converted to PLP and incorporated into phosphorylase. 3. In this study we have resolved phosphorylase-bound label from that associated with the other PLP-containing enzymes and free label by affinity and size-exclusion chromatography. 4. The decay of radioactive pools was assessed after an extended period post-injection to minimize the effects of isotope reutilization. 5. These modifications have allowed refinement of our previous estimate of the rate of degradation of muscle phosphorylase.
authors.affiliation: Department of Biochemistry, University of Liverpool, England.
authors.forename: E J
authors.initials: EJ
authors.lastname: Cookson
authors.forename: R J
authors.initials: RJ
authors.lastname: Beynon
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009132:Muscles / Q000201:enzymology; D006005:Phosphorylases / Q000378:metabolism*; D011732:Pyridoxal Phosphate / Q000378:metabolism*; D011736:Pyridoxine; D014316:Tritium
chemical_list: D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D014316:Tritium; D011732:Pyridoxal Phosphate; D006005:Phosphorylases; D011736:Pyridoxine