Biomaterial Database

Chemical modification of a functional arginine residue in diadenosine 5',5'''-P1,P4-tetraphosphate (Ap4A) phosphorylase I from Saccharomyces cerevisiae. 1991

A K Robinson, and L D Barnes

Department of Biochemistry, University of Texas Health Science Center, San Antonio 78284-7760.

Phenylglyoxal, a reagent with high specificity for arginine residues, inactivated Ap4A phosphorylase I from Saccharomyces cerevisiae in a pseudo-first-order manner. The second-order rate constant was 11.5 +/- 2.5 M-1 min-1. The loss of activity was a linear function of the incorporation of [7-14C]phenylglyoxal. The incorporation of 1.9 +/- 0.4 mol of phenylglyoxal/mol of enzyme accounted for complete loss of activity. The specificity of inactivation by phenylglyoxal was tested in the presence of ApnA (n = 2-6), ADP, ATP and Pi. The substrates, Ap4A, Ap5A and Pi protected the enzyme against inactivation, but Ap2A, Ap3A and Ap6A did not. Ap4A, Ap5A and Pi reduced the rate of inactivation by about 70%, 60% and 37% respectively. The Ap4A phosphorolysis products, ADP and ATP, also partially protected the enzyme against inactivation by phenylglyoxal. Thus Ap4A phosphorylase I probably contains an arginine residue in the binding site for Ap4A.

UI	MeSH Term	Description	Entries
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D009713	Nucleotidyltransferases	A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.	Nucleotidyltransferase
D010658	Phenylglyoxal	A reagent that is highly selective for the modification of arginyl residues. It is used to selectively inhibit various enzymes and acts as an energy transfer inhibitor in photophosphorylation.
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D001345	Autoradiography	The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)	Radioautography
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker