Phospho-dephosphohybrids of rabbit skeletal muscle phosphorylase (EC 2.4.1.1; alpha-1,4-glucan: orthophosphate glucosyl transferase) have been prepared and stabilized by attachment to Sepharose activated by cyanogen bromide. They can be distinguished from phosphorylase a by their sensitivity to inhibition by glucose-6-phosphate and activation by adenosine 5'-monophosphate. Stable hybrids have a...

The essential role of pyridoxal-5’-phosphate for the activity of all cY-glucan phosphorylases received strong support from recent studies with bacterial phosphorylases [ 11. The advantage of utilizing these enzymes for the study of the role of pyridoxal-P is obvious since they neither depend on allosteric effectors or covalent modification for the expression of activity [l-6]. The 5’-phosphate ...

The neurocirculatory responses to exercise are exaggerated in hypertension, increasing cardiovascular risk, yet the mechanisms remain incompletely understood. The aim of this study was to examine the in vitro effectiveness of pyridoxal-5-phosphate as a purinergic (P2) receptor antagonist in isolated murine dorsal root ganglia (DRG) neurons and the in vivo contribution of P2 receptors to the neu...

The chemical modification of lysine residues in human alpha-thrombin has been used to study the interaction of thrombin with human platelets. Phosphopyridoxylation of thrombin using pyridoxal 5'-phosphate (pyridoxal-P) has been shown to inhibit the fibrinogen clotting activity of thrombin but not the catalytic activity (Griffith, M. J. J. Biol. Chem. 254, 3401-3406). Phosphopyridoxylation resul...