A rationale for the design of an inhibitor of tyrosyl kinase

Chiun-Jye Yuan, S. Jakes, S. Elliott, D. J. Graves*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Scopus citations

Abstract

Two gastrin analogs containing a D- and a L-tetrafluorinated tyrosyl residue (Arg-Arg-Leu-Glu-Glu-Glu-Glu-Glu-Ala-(F4)Tyr-Gly) were synthesized and tested as substrates and inhibitors of the insulin receptor kinase. No phosphorylation of these peptides was observed, but both gastrin analogs were effective inhibitors in the μM range. Although the D- and L-tetrafluorotyrosine-gastrin analogs differ in the sequence by only 1 amino acid residue, a different inhibitory pattern was obtained with the insulin receptor. The inhibition of all-L-isomer is competitive with respect to both the protein substrate, reduced, S-carboxymethylated, and maleylated lysozyme (RCMM-lysozyme), and ATP with a K(i) value of 4 μM. This result corroborates a previous finding (Walker, D.H., Kuppuswamy, D., Visvanathan, A., and Pike, L. J. (1987) Biochemistry 26, 1428-1433) that the kinetic mechanism for insulin receptor is a random Bi Bi mechanism. Different from the L-isomer, the D-analog is competitive to RCMM-lysozyme and noncompetitive toward ATP and gives an apparent inhibition constant of 20 μM. A free tetrafluorotyrosine also shows a competitive inhibition to protein substrate, RCMM-lysozyme (K(i) = 18 mM) whereas free tyrosine shows no effect on the activity of insulin receptor. These results show the importance of the charge state and nucleophilicity of the phenolic component in substrate recognition and catalysis and provide a rationale for the design of inhibitors of tyrosyl phosphorylation.

Original languageEnglish
Pages (from-to)16205-16209
Number of pages5
JournalJournal of Biological Chemistry
Volume265
Issue number27
StatePublished - 22 Oct 1990

Fingerprint Dive into the research topics of 'A rationale for the design of an inhibitor of tyrosyl kinase'. Together they form a unique fingerprint.

Cite this