ISOLATION AND IDENTIFICATION OF ANGIOTENSIN-LIKE PEPTIDES FROM THE PLASMA OF THE SNAKE BOTHROPS-JARARACA

Two distinct hypertensive peptides were purified and characterized fro m Bothrops jararaca (Bj) plasma incubated at pH 4, 37 degrees C, 24 hr . These peptides were active on rat and Bj blood pressure, on rat isol ated uterus, on guinea-pig isolated ileum and on Bj isolated duodenum. At the releasing conditions no further activities were found for kini nases, angiotensinases or angiotensin converting enzymes. The peptides were purified by ethanol/ether extraction, Sephadex G-25 gel filtrati on, semipreparative reverse-phase (C-18) HPLC and analytical (C-18) HP LC. The amino-acid sequences of the purified peptides corresponded to (Ile(5))AII and (Val(5)-Tyr(9))AI and their molecular masses were conf irmed by mass spectrometry as 1046.6 and 1348.0 respectively. The pres ence oi those two angiotensins on Bj plasma may have some evolutionary significance since (Ile(5))AII is known as a mammalian angiotensin an d (Val(5))AII as a non-mammalian one.