Olga B. Henriques

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.

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. jararaca plasma and the conversion of angiotensin I to angiotensin II by kininase II from guinea-pig ileum tissue. The peptide also increased the depressor effect of bradykinin on arterial blood pressure in the anaesthetized rat.

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.

Plasma enzymes that release kinins.

Abstract The present work deals with a further characterization of the kinin liberation process in plasma. Purified plasma kallikrein, plasmin, and kininogenic substrates were prepared from human or equine plasma, and some of their properties were compared. Plasmin and kallikrein were shown to liberate kinins from horse plasma heated for 3 hr at 56°, a kallikreinogen-free substrate; “acid-treated” plasma or purified kininogen was used as substrate only by plasmin. Experiments with these last substrates allowed the conclusion that plasmin by itself has the capacity to release kinins. Hydrolytic actions of kallikrein and plasmin on p- toluene sulfonyl- l -arginine methyl ester (TAMe), benzoyl- l -arginine ethyl ester (BAEE), lysine ethyl ester (LEE), and benzoyl- l -arginine-amide (BAA) showed that plasmin hydrolyzes TAMe, BAEE, and LEE more effectively than does plasma kallikrein. BAA was not hydrolyzed by human or equine plasmin, but it was split by plasma kallikrein. Plasma kallikrein did not hydrolyze casein. A new method of plasma kallikrein purification was developed.

Partial purification of the plasma substrate for the bradykinin-releasing enzyme from the venom of Bothrops jararaca

Abstract The substrate for the bradykinin-releasing enzyme from the venom of Bothrops jararaca was purified 170-fold from fresh horse plasma. Hortons substrate, prepared by acidification of plasma to pH 2.0, heating to 38°C, and neutralization to pH 7.0 at low temperature, was fractionally precipitated with ammonium sulfate, and the fraction obtained between 0.33 and 0.50 saturation was chromatographed on diethylaminoethyl (DEAE)-cellulose. The activity of the bradykinin-releasing enzyme of the venom on crude plasma and on the fractions obtained during the course of purification of bradykininogen is compared with that of trypsin.

Purification and properties of Bothrops protease A

Abstract Bothrops protease A, one of the proteolytic enzymes found in the venom of the snake, Bothrops jararaca, was purified by a method which leads to the same purification but gives a better yield than the method previously used. The hydrolytic potency of Bothrops protease A on p-toluenesulfonyl- l -arginine methyl ester, benzoyl- l -arginine amide, protamine, and l -lysine ethyl ester was found to be one half, one eighth, one ninth, and one hundredth as great as that of crystalline trypsin, respectively. Bothrops protease A was found to be stable at room temperature between pH 3 and 9.

Potentiation of bradykinin action on smooth-muscle by cysteine

Die Wirkung von Bradykinin, aber nicht von Angiotensin I und II auf das isolierte Meerschweinchenileum und den Uterus der Ratte wird durch Cystein verstärkt. Die Sensibilisierung der glatten Muskulatur ist auf die Hemmung der Kininase, die sich in den Geweben jener Organe befindet, durch Cystein zurückzuführen. Fragmente von Uterus oder Heum von Tieren, deren hintere Extremitäten unter Druck mit Tyrode durchströmt und zur vollkommenen Ausblutung gebracht wurden, inaktivieren das Bradykinin, wenn sie damit inkubiert werden. Diese Inaktivierung kann durch Vorbehandlung der Organe mit Cystein verhindert werden.

Glass-activated plasma kallikrein.

Abstract Plasma kallikrein from horse plasma was purified by adsorption on glass-surface followed by chromatography on DEAE-cellulose. It is shown that kallikrein is activated, simultaneously adsorbed and afterwards eluted from glass surface in the same conditions as described by other authors to separate Hageman factor from plasma. Evidence is presented suggesting that glass-activated and acid-activated kallikrein are the same substance.

Proteolytic, esterase and kinin-releasing activities of some Soviet snake venoms

Abstract The casein-, p-toluene-sulfonyl- l -arginine methyl ester- and benzoyl- l -arginine amide-hydrolyzing as well as the kinin-releasing activities of the viperids Vipera lebetina, Vipera ursini and Echis carinatus, the crotalids Agkistrodon halys halys and Agkistrodon halys blomhoffii and the elapid Naja naja oxiana venoms were studied. Viperid venoms were shown to contain kinin-releasing enzyme, as previously reported for crotalid venoms. The effect of inhibitors of proteolytic enzymes, such as aminocaproic acid, soy bean trypsin inhibitor and Trasylol, was studied on the kinin-releasing activity of the venoms mentioned above. Only the kinin-releasing activity of V. lebetina venom was inhibited by soy bean inhibitor.

Glass activated kallikrein from human plasma

Abstract It is shown that when preparing human plasma kallikrein by adsorption on glass surface a 30 sec period of shaking leads to more active preparations and a better yield than longer periods of shaking. A gradual decrease of the kininogenase specific activity of the eluates obtained after 1, 2, 5 and 10 min shaking of the plasma with glass beads was found. No parallelism between the kininogenase and esterolytic activities of the kallikrein preparations was observed, suggesting the presence of other esterase(s) in the eluates. Glass activation of prekallikrein was not prevented by previous incubation of the plasma with lima bean trypsin inhibitor which has been shown 6 to inhibit factor XII, generally considered to be the enzyme responsible for the activation of prekallikrein.