Retinal cyclic-GMP phosphodiesterase gamma-subunit: identification of functional residues in the inhibitory region.
Previously, we have domain-mapped the 87 amino acid PDE gamma inhibitory subunit of the retinal phosphodiesterase (PDE) alpha beta gamma 2 complex using synthetic peptides. The PDE gamma subunit has a binding domain for transducin-alpha (T alpha) and for PDE alpha/beta within residues # 24-45 and an inhibitory region for PDE alpha/beta within residues # 80-87. In order to establish the role of individual amino acids in the function of the PDE gamma inhibitory subunit, peptides of PDE gamma # 63-87 and mutant peptides were synthesized and utilized in PDE inhibition assays. The following peptides exhibited a decreased ability to inhibit PDE alpha/beta: All were from PDE gamma # 63-87; PDE gamma Tyr 84----Gly, PDE gamma Phe 73----Gly and PDE gamma Gln 83----Gly.
Gonzalez
K
K
Department of Biochemistry, Kansas State University, Manhattan 66506.
Cunnick
J
J
Takemoto
D
D
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000595:Amino Acid Sequence; D004789:Enzyme Activation; D007700:Kinetics; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology*; D012374:Rod Cell Outer Segment / Q000201:enzymology*; D014357:Trypsin / Q000494:pharmacology
D046911:Macromolecular Substances; D010446:Peptide Fragments; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D014357:Trypsin