Characterization of a new bradykinin-potentiating peptide (TmF) from Trimeresurus mucrosquamatus.
A novel bradykinin-potentiating peptide (BPP), designated as TmF, has been purified to homogeneity from the venom of Trimeresurus mucrosquamatus by 70% cold methanol extraction, Sephadex G-15 gel filtration and reverse-phase high performance liquid chromatography (RP-HPLC). The amino acid sequence of TmF was determined to be pGlu-Gly-Arg-Pro-Leu-Gly-Pro-Pro-Ile-Pro-Pro (pGlu denotes pyroglutamic acid), which shared high homology with other BPPs. The molecular mass of TmF was 1.1107 kD as determinated by electrospray ionization-mass spectrometry (ESI-MS), which was in accordance with the calculated value of 1.1106 kD. The potentiating   unit   of TmF to bradykinin-induced (BK-induced) contraction on the guinea-pig ileum in vitro was (1.13 +/-0.3) unit (mg/L), and TmF (5.0 x10(-4) mg/kg) increased the pressure-lowering-effect of bradykinin (5.0 x10(-5 )mg/kg) with approximate descent value of (14 +/-2) mmHg. In addition, TmF inhibited the conversion of angiotensin I to angiotensin II, 2 x10(-3) mg of TmF caused 50% inhibition (IC(50)) of angiotensin- converting enzyme (ACE) hydrolyzing activity to bradykinin.
Jia
Yong-Hong
YH
Department of Animal Toxinology, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming 650223, China. jiayh_78@hotmail.com
Li
Dong-Sheng
DS
Zhu
Shao-Wen
SW
Zhang
Li-Yue
LY
Ding
Li-Sheng
LS
Wang
Wan-Yu
WY
Xiong
Yu-Liang
YL
D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology*; D002415:Cats; D003435:Crotalid Venoms / Q000032:analysis*; D004357:Drug Synergism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology*; D013722:Teprotide / Q000494:pharmacology
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D003435:Crotalid Venoms; D009842:Oligopeptides; C029748:Trimeresurus venoms; D013722:Teprotide; D001920:Bradykinin