Blomhotin: a novel peptide with smooth muscle contractile activity identified in the venom of Agkistrodon halys blomhoffii

PI novel peptide has been isolated from the venom of Agkistrodon halys blom hoffii using a bioassay that monitors the stimulant effect on rat stomach f undus. The 11-amino acid peptide, named blomhotin, was purified to homogene ity by gel-filtration column chromatography and reverse-phase HPLC. The ami no acid sequence of blomhotin was determined to be pGlu-Gly-Arg-Pro-Pro-Gly -Pro-Pro-Ile-Pro-Arg, which is similar to that of bradykinin-potentiating p eptides which themselves cause no contraction of smooth muscle. The contrac tion induced by blomhotin showed homologous desensitization, implicating th e involvement of a blomhotin-specific site in the response. (C) 1999 Elsevi er Science Ltd. All rights reserved.