Acquisition of a "Group A"-selective Src kinase inhibitor via a global targeting strategy

Abstract

A "global" strategy for the acquisition of selective high affinity inhibitors for the Src kinase subfamily of tyrosine kinases is described. Members of the Src family exhibit a strong amino acid sequence homology. However, recent studies have revealed differences in the relative spatial relationships of the three distinct protein-binding domains present in these enzymes. We have constructed an inhibitor, using an amalgamation of combinatorial methods and directed design, which simultaneously associates with the active site and an ancillary protein-binding region (SH2 domain). The inhibitor exhibits high inhibitory potency and selectivity for the Group A versus Group B subset of Src kinases.

Scheme 1

Two step synthetic protocol for the preparation of the low μM affinity SH1 domain-targeting inhibitor 7 (Table 1).

Scheme 2

Preparation of Bivalent Inhibitors 11-16.

Figure 1

Two-domain-targeting inhibitor for the Src kinase family. The individual SH1- and SH2-targeting sequences are designed to have approximately equal affinities for their respective domains.