Inactivation of phosphorylase b by potassium ferrate. Identification of a tyrosine residue involved in the binding of adenosine 5'-monophosphate.
The site of reaction of potassium ferrate (K2FeO4) with rabbit muscle phosphorylase b has been further characterized in an extension of previously published studies (Lee, Y. M., and Benisek, W. F. (1976) J. Biol, Chem. 251, 1553-1560) reporting inactivation of the enzyme by this reagent. The tryptic peptide composed of residues 70 to 80 of the enzyme's polypeptide chain was shown to contain a tyrosine residue which is chemically modified by ferrate and which is protected by 5'-AMP. The sequence of this peptide obtained from both untreated and ferrate-treated phosphorylase b was determined, and the results showed that tyrosine-75 was the residue with which ferrate reacts.
D000249:Adenosine Monophosphate; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D007501:Iron / Q000494:pharmacology; D009132:Muscles / Q000201:enzymology; D010446:Peptide Fragments / Q000032:analysis; D006005:Phosphorylases / Q000037:antagonists & inhibitors; D011485:Protein Binding; D011817:Rabbits; D014443:Tyrosine
D010446:Peptide Fragments; D000249:Adenosine Monophosphate; D014443:Tyrosine; D007501:Iron; D006005:Phosphorylases