Enzymatic profile of latex from Araujia angustifolia and Araujia hortorum fruits

OBREGÓN, DAVID; CURCIARELLO, R.; LUFRANO, D.; PRIOLO, N.S.

Córdoba, Argentina

Congreso; XXXVIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2002

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Different enzymatic activities were observed in latex from two species of Araujia (Asclepiadaceae): A. angustifolia (Hook. et Arn.) Decaisne  and A. hortorum Fourn. Latex of both species was collected on 55mM citric-phosphate buffer (pH 6.4) with 5mM EDTA and cysteine and ultracentrifuged at 100,000 ´ g during 60 min. This supernatant was called crude extract. Protein content and the following catalytic activities were assayed: amidase, protease, polygalacturonidase, xilanase, carboxy methylcellulase, methyl esterase, and rhamnogalacturonidase were assayed on crude extracts. Both especies showed amidasic activity on L-pyroglutamyl-l-phenylalanyl-l-leucine-p-nitroanilide, proteolytic activity on 1% casein in Tris-HCl pH 8.5; polygalacturonidase activity using 1% polygalacturonicacid in acetic-acetate buffer pH 4.5, andmethyl pectin esterase on 1% pectin in citric phosphate pH 6.8 in presence of 0.02M Ca Cl2. Crude extract from A. angustifolia was purified by cationic exchange chromatography (FPLC) with SP Sepharose. Nine fractions were eluted when a 0-2 M ClNa gradient was applied. Activity of purified fractions was tested on the aforementioned substrates.