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.

A new bradykinin-potentiating peptide (peptide P) isolated from the venom of Bothrops jararacussu (jararacuçu tapete, urutu dourado).

Several bradykinin potentiators were identified in the venom of Bothrops jararacussu by chromatographic techniques and biological assays. One of them which was isolated inhibited the angiotensin-converting enzyme in vitro and potentiated the bradykinin-induced lowering of the arterial pressure in the rat.

Isolation of a bradykinin-potentiating factor from scorpion Tityus serrulatus venom.

A bradykinin-potentiating factor was isolated and characterized from the scorpion Tityus serrulatus venom by chromatographic techniques and reverse phase followed by biological assays. This factor showed to be able to potentiate the contractile activity of the isolated guinea-pig ileum, inhibited the angiotensin-converting enzyme and potentiated the bradykinin-induced lowering of the arterial blood pressure in the rat.

Kallikrein isolated from commercial crystalline pepsin preparations.

1. An experiment designed to study the relationship between pH and kininogenase activity of three commercial preparations of porcine crystallized pepsin showed that each preparation had two well separated pH optima, pH 4 and 8. 2.

[Purification and enzyme study of kininogens I and II from human plasma].

Kininogens I (HMW) and II (LMW) were isolated and partially purified from human plasma. The disappearance of kininogen I was prevented by the use of hexadimethrine bromide, which inhibits the activation of plasma prekallikrein. The two kininogens were separated by chromatography on DEAE-cellulose.

[Purification of kininogen II (LMW) from human plasma].

Plasma supernatant in which kallikrein has been activated and removed by glass powder whilst kininogen I (HMW) has been consumed by the activated kallikrein, was used for the preparation of kininogen II. It was purified by chromatography on DEAE-cellulose followed by gel filtration on G-200 Sephadex. The purification of kininogen II was assessed from determinations of the amount of kinin released (expressed as bradykinin) as measured on the isolated guinea pig ileum, using samples incubated with human salivary kallikrein or trypsin.