CD45 PROTEIN-TYROSINE-PHOSPHATASE - DETERMINATION OF MINIMAL PEPTIDE LENGTH FOR SUBSTRATE RECOGNITION AND SYNTHESIS OF SOME TYROSINE-BASED ELECTROPHILES AS POTENTIAL ACTIVE-SITE-DIRECTED IRREVERSIBLE INHIBITORS

Using fyn PTK as a template, a series of phosphopeptides 1-11 spanning in length from 1-14 amino acids was prepared. Kinetic evaluation of 1 -11 suggest that CD45 does not have a strong preference for its N- or C-terminal amino acids and that extended phosphopeptides are not requi red for efficient substrate turnover.