Abstract
Three toxic polypeptides were purified from the venom of the Brazilian scorpion Tityus serrulatus by means of gel filtration in Sephadex G-50 and ion-exchange chromatography in carboxymethylcellulose. The peptides are basic molecules with molecular weights in the range of 7000 for which the amino acid compositions and sequences were determined. The effect of the purified peptides on pancreatic exocrine secretion in the guinea pig was studied. Biochemical measurements show that the cells are stimulated by these peptides to discharge their zymogen granules. Light and electron microscopic images confirm the biochemical measurements. At the light microscope level, acinar cells show dramatically fewer zymogen granules than in control pancreas with the appearance of large vacuoles and some loss of morphological integrity. Electron micrographs display apical regions devoid of zymogen granules and condensing vacuoles whereas acinar lumina contain crystalline secretory material. The secretory effect observed in vitro is comparable to that of carbamylcholine and that of the peptidergic secretagogue cholecystokinin-pancreozymin.
Highlights
Three toxic polypeptides were purified from the as in experimental animals were described (21)
Since acute pancreatitis is a unique result of a venomous sting in humans, it was our purpose to determine the association between pure protein components isolated from the venom of the Brazilianscorpion, T. serrulutus, and measurements of secretory dischargeinguinea pig pancreas in uitro
Toledo and Neves (36) and ourgroup (27,40) have demonstrated thepresence of more than one toxiccomponent was subsequently purified by rechromatography of the dialyzed fractions througha second CM-cellulose columnequilibrated with50 mM sodium phosphate buffer, pH 6.0
Summary
Three toxic polypeptides were purified from the as in experimental animals were described (21). Since acute pancreatitis is a unique result of a venomous sting in humans, it was our purpose to determine the association between pure protein components isolated from the venom of the Brazilianscorpion, T. serrulutus, and measurements of secretory dischargeinguinea pig pancreas in uitro. The first CM-cellulose column (0.9 X 30 cm) was developed in ammonium acetate buffer, pH 4.7 The first report on the isolation of a toxic component, main toxic components of the venom (28) Eachof these components named Tityustoxin, from the venom of the scorpion Tityus serrulutus Lutz and Mello, was published in 1966 (13). Toledo and Neves (36) and ourgroup (27,40) have demonstrated thepresence of more than one toxiccomponent was subsequently purified by rechromatography of the dialyzed fractions througha second CM-cellulose columnequilibrated with mM sodium phosphate buffer, pH 6.0. A lineargradient from 0-0.5 M NaCl inthesame buffer was used toelutethe toxic proteinsin homogeneous form
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