| abstract |
A method of screening a compound or a polypeptide which inhibits AST activity, or inhibits PAR activation, mucus production promotion, cell proliferation, calcium flow into cells or EGFR pathway activation by AST; and a method of assaying AST in vivo and in biological cells or samples. ASTs which are mammalian AST proteins comprising the whole amino acid sequence represented by SEQ ID NO:1 or 2 or a part thereof, or an amino acid sequence having a 66% homology with the amino acid sequence represented by SEQ ID NO:1 and in which a propeptide moiety is bonded to a trypsin-like moiety via a disulfide bond; nucleic acids encoding the same; antibodies binding to the same; a method of assaying AST by using these antibodies; and a method of assaying the AST inhibitory activity or the activity of inhibiting PAR activation, mucus production promotion, cell proliferation, calcium flow into cells or EGFR pathway activation by AST of a compound or a polypeptide to be assayed. |