Title: Characterisation, stabilisation and possible biotechnological applications of new proteolytic enzymes from Solanum granuloso-leprosum

Authors: Diego Valles, Shirley Furtado, Carolina Villadoniga, Ana Maria B. Cantera

Addresses: Laboratorio de Enzimas Hidroliticas, Facultad de Ciencias, Igua 4224, Catedra de Bioquimica, Facultad de Quimica, Gral. Flores 2124, C.C. 1157 Universidad de la República (UdelaR), Montevideo, Uruguay. ' Laboratorio de Enzimas Hidroliticas, Facultad de Ciencias, Igua 4224, Catedra de Bioquimica, Facultad de Quimica, Gral. Flores 2124, C.C. 1157 Universidad de la República (UdelaR), Montevideo, Uruguay. ' Laboratorio de Enzimas Hidroliticas, Facultad de Ciencias, Igua 4224, Catedra de Bioquimica, Facultad de Quimica, Gral. Flores 2124, C.C. 1157 Universidad de la República (UdelaR), Montevideo, Uruguay. ' Laboratorio de Enzimas Hidroliticas, Facultad de Ciencias, Igua 4224, Catedra de Bioquimica, Facultad de Quimica, Gral. Flores 2124, C.C. 1157 Universidad de la República (UdelaR), Montevideo, Uruguay

Abstract: An extract possessing proteolytic activity was obtained by grinding the ripe fruit Solanum granuloso-leprosum, a tree of the family Solnaceae. The crude extract had maximum activity at pH between 5.2 and 7.6, and temperatures between 50°C and 55°C. It was stable at pH 7.6 and freezing temperature. The proteolytic activity of this plant product was activated and stabilised by reducing agents. Purification was carried out using simple and economical procedures, including ethanolic precipitation and gel-filtration chromatography. The main proteolytically active fraction obtained was inhibited by iodoacetamide and E-64, indicating its cysteinic nature. This fraction had a pI range of 7.5–8.3. The enzyme preparation was unstable at temperature above 4°C, but was stabilised by adsorption onto alumina. Its hydrolytic action was studied on casein whey and haemoglobin substrates, which represent ecologically contaminating fractions of industrial waste.

Keywords: proteases; Solanum granuloso leprosum; cysteine peptidase; fruit protease; enzyme purification; characterisation; biotechnology; industrial waste; environmental contamination.

DOI: 10.1504/IJBT.2004.005517

International Journal of Biotechnology, 2004 Vol.6 No.4, pp.346 - 360

Published online: 12 Oct 2004 *

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