Isolation and characterization of a new bradykinin potentiating octapeptide from gamma-casein.

Peptides that display bradykinin-potentiating activity have been obtained from a number of distinct sources, such as snake venoms, fibrinogen, and casein. This paper describes the isolation and sequencing of a novel bradykinin-potentiating peptide, generated by tryptic hydrolysis of the gamma-casein chain. No homology was found to other known vasoactive or vasopotentiating peptides.

Isolation and properties of a T-kininogenase from bovine erythrocyte membranes.

A kininogenase from bovine erythrocyte membranes has been purified 140-fold by affinity chromatography on pepstatin A-Agarose followed by ion exchange chromatography on CM Cellulose. The purified enzyme showed an apparent molecular weight of 31,000 daltons as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its pH optimum is 7.

Peptide T, a novel bradykinin potentiator isolated from Tityus serrulatus scorpion venom.

A bradykinin-potentiating peptide was isolated and characterized from venom of the scorpion Tityus serrulatus by chromatographic techniques followed by biological assays. The complete amino acid sequence (13 residues) of peptide is presented. The peptide potentiated the contractile activity of bradykinin on the isolated guinea-pig ileum, and inhibited the hydrolysis of bradykinin by angiotensin-converting enzyme from B.

Antivenom and biological effects of ar-turmerone isolated from Curcuma longa (Zingiberaceae).

A potent antivenom against snakebite was isolated from Curcuma longa, a plant commonly used in traditional Brazilian medicine. The fraction consisting of ar-turmerone neutralized both the hemorrhagic activity present in Bothrops jararaca venom, and the lethal effect of Crotalus durissus terrificus venom in mice. Immunological studies demonstrated that this fraction also inhibited the proliferation and the natural killer activity of human lymphocytes.

Biologically active peptides from Bothrops jararacussu venom.

The venom of the Brazilian snake Bothrops jararacussu, was found to contain peptides capable of potentiating the smooth muscle contracting activity of bradykinin (BK). Chromatographic separation on Sephadex G-25 and Sephadex G-10 respectively, yielded an active peptide which at a concentration of 0.6 micrograms/ml doubled the effect of a single dose of BK on the isolated guinea-pig ileum.