Aislamiento, purificación y caracterización de una lectina de la semilla del poró, Erythrina costaricensis (Leguminosae) / Isolation, purification and characterization of a lectin from the seed of Erythrina costaricensis (Leguminosae)

La lectina de la semilla de E. costaricensis se purificó a partir del extracto crudo mediante filtración por Sephadex G-100 y cromatografía por DEAE-Sephadex A-50. La electroforesis en gel de acrilamida (PAGE) demostró la presencia de una única banda proteica. El isoelectroenfoque analítico demostró la presencia de cuatro isolectinas. La masa relativa obtenida por filtración en Sephadex fue de 58 KDa y por PAGE en condiciones reductoras de 29.5 KDa. La proteína es fundamentalmente un dímero no unido por enlaces disulfuro, con un contenido de 6.5% de azúcares neutros. Es estable hasta 70-C y en un àmbito de pH de 2 a 10. Aglutina indistintamente los eritrocitos humanos y diferencia entre eritrocitos de origen animal, aglutinando los de conejo y pollo y no los de caballo, cabra, carnero ni rata. La galactosa N-acetil-galactosamina, lactosa y el EDTA inhiben su acción aglutinante, los iones calcio y mangneso son activadores. No se encontró efecto vasopresor al inyectar la lectina itravenosamente en ratas

Characterization of a lectin-like protein isolated from Lachesis muta snake venon

A lectin-like protein was isolated from L. muta venom by gel filtration on BIO Gel P-100 followed by column Chromatography on DEAE-Sephadex A-50. The protein eluted at 0.4 M NaCl in 0.01 Tris pH 7.3 and exhibited agglutinin activity toward 0**+ human erytrocytes. The protein is a dimer with Mr 28 kDa. Amino acid analysis revealed high content or tryptophan and acid recidues and low content of cysteine and methionine residues. No neural carbohydrates an sialic acid were detected. Circular dichroic spectrum shows 78% of B structure and 1% of alfa structure. In vitro experiments with ery throcytes from rat, rabbit and dog revealed strong agglutination while red blood cells from mice, sheep and goat were not agglutinated. In vivo experiments using non-anesthetized rats, a sharp and prolonged fall in the blood pressure was observed at protein dose of 1.5 mg/kg. Double dose of protein caused the death of the animal

Isolation and partial characterization of Lachesis muta melanocephala coagulant proteinase: biochemical parameters of the venom

The coagulant proteinase of L. m. melanocephala was purified by DEAE Sephadex A-50 followed by agmatine CH- Sepharose and gel filtration on Sephadex G-100. The enzyme exhibited m,any of the properties adscribed to -mudasa-, the coagulant proteinase from L. m. stenophirs venom. Its molecular weight by gel filtration was 35 kDa and its specific clotting activity was 702 NIH/mg of protein. A 32 fold increase in the clotting was obtained by purification. The coagulant proteinase exibited esterolytic activities toward lysine and arginine esters as well as amidolytic. Significant differences are observed when compared with the activities of -mudasa-, the former is less esterolytic, although its activity toward TLEME is higher. Significant differences in the activities are also observed when the venom from the Pacific and Atlantic L. muta populations (corresponding to the subspecies L.m. melanocefala and L.m. Stenophyrs) are compared toward the same substrates. The Pacific type is less amidolytic and more esterolytic toward BAME and BAEE, although toward the lysine and tyrosine esters no significant differences are observed. The venon from the Pacific populations is more coagulant and less proteolytic than the venom from the Atlantic population. Analytical isoelectric focusing of both populations of venom revealed important differences in the number and intensity of the protein bands. The results here given further substantiate the taxonomical differentiation already given to the Pacific and Atlantic Costa Rican population of L. muta.