pubmed:abstractText |
Fibroblast activation protein (FAP) is a serine protease of undefined endopeptidase specificity implicated in tumorigenesis. To characterize FAP's P(4)-P(2)(') specificity, we synthesized intramolecularly quenched fluorescent substrate sets based on the FAP cleavage site in alpha(2)-antiplasmin (TSGP-NQ). FAP required substrates with Pro at P(1) and Gly or d-amino acids at P(2) and preferred small, uncharged amino acids at P(3), but tolerated most amino acids at P(4), P(1)(') and P(2)('). These substrate preferences allowed design of peptidyl-chloromethyl ketones that inhibited FAP, but not the related protease, dipeptidyl peptidase-4. Thus, FAP is a narrow specificity endopeptidase and this can be exploited for inhibitor design.
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pubmed:affiliation |
Department of Molecular Oncology, Genentech, Inc., 1 DNA Way - MS42, South San Francisco, CA 94080, USA.
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