Glass, D. B., Feller, M. J., Levin, L. R., Walsh, D. A. (February 1992) Structural basis for the low affinities of yeast cAMP-dependent and mammalian cGMP-dependent protein kinases for protein kinase inhibitor peptides. Biochemistry, 31 (6). pp. 1728-34. ISSN 0006-2960 (Print)0006-2960 (Linking)
Abstract
Affinities of the catalytic subunit (C1) of Saccharomyces cerevisiae cAMP-dependent protein kinase and of mammalian cGMP-dependent protein kinase were determined for the protein kinase inhibitor (PKI) peptide PKI(6-22)amide and seven analogues. These analogues contained structural alterations in the N-terminal alpha-helix, the C-terminal pseudosubstrate portion, or the central connecting region of the PKI peptide. In all cases, the PKI peptides were appreciably less active as inhibitors of yeast C1 than of mammalian C alpha subunit. Ki values ranged from 5- to 290-fold higher for the yeast enzyme than for its mammalian counterpart. Consistent with these results, yeast C1 exhibited a higher Km for the peptide substrate Kemptide. All of the PKI peptides were even less active against the mammalian cGMP-dependent protein kinase than toward yeast cAMP-dependent protein kinase, and Kemptide was a poorer substrate for the former enzyme. Alignment of amino acid sequences of these homologous protein kinases around residues in the active site of mammalian C alpha subunit known to interact with determinants in the PKI peptide [Knighton, D. R., Zheng, J., Ten Eyck, L. F., Xuong, N-h, Taylor, S. S., & Sowadski, J. M. (1991) Science 253, 414-420] provides a structural basis for the inherently lower affinities of yeast C1 and cGMP-dependent protein kinase for binding peptide inhibitors and substrates. Both yeast cAMP-dependent and mammalian cGMP-dependent protein kinases are missing two of the three acidic residues that interact with arginine-18 in the pseudosubstrate portion of PKI. Further, the cGMP-dependent protein kinase appears to completely lack the hydrophobic/aromatic pocket that recognizes the important phenylalanine-10 residue in the N-terminus of the PKI peptide, and binding of the inhibitor by the yeast protein kinase at this site appears to be partially compromised.
| Item Type: | Paper |
|---|---|
| Uncontrolled Keywords: | Amino Acid Sequence Animals Binding Sites Cattle Cyclic AMP/*pharmacology Cyclic GMP/*pharmacology Kinetics Molecular Sequence Data Myocardium/*enzymology Oligopeptides/metabolism Peptide Fragments/chemistry/*pharmacology Peptides/chemistry/*pharmacology *Protein Kinase Inhibitors Protein Kinases/chemistry/metabolism Saccharomyces cerevisiae/*enzymology Substrate Specificity |
| Subjects: | bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > transcription factor > Cyclic AMP bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > kinase organism description > yeast |
| CSHL Authors: | |
| Communities: | CSHL labs |
| Depositing User: | Matt Covey |
| Date: | 18 February 1992 |
| Date Deposited: | 01 Oct 2015 19:02 |
| Last Modified: | 01 Oct 2015 19:02 |
| Related URLs: | |
| URI: | https://repository.cshl.edu/id/eprint/31773 |
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