African Journal of Biotechnology Vol. 4 (7), pp. 703-707, July 2005          
ISSN 1684–5315 © 2005 Academic Journals

Full Length Research Paper

Purification of acidic protease from the cotyledons of germinating Indian bean (Dolichos lablab L. var lignosus) seeds

Vadde Ramakrishna* and P. Ramakrishna Rao

Department of Biochemistry, Sri Krishnadevaraya University,

Anantapur – 515 003. A.P., India.

*Corresponding Author E-Mail: vrkrishna70@rediffmail.com; vrkrishna70@yahoo.co.in.

Accepted March, 2005

The positive correlation between the developments of acid, neutral and alkaline proteases (azocaseinolytic) with protein depletion suggest the involvement of these proteases in the degradation of proteins in germinating Indian bean.  These proteases increased in the early stages of germination and decreased later. However, the activity of acid proteases was higher throughout the germination period compared with the activities of neutral and alkaline proteases.   The acid protease from the cotyledons of 4-day old germinating Indian bean seedlings was purified to 152 folds by a five step procedure comprising - crude extract from cotyledons, (NH₄)₂SO₄ fractionation, DEAE-cellulose, CM-cellulose and finally casein-agarose affinity chromatography. The molecular mass of acidic protease is 32 kDa.

Key words: Dolichos lablab, proteolytic enzymes, acidic protease, purification, protein mobilization, germination.