Structural Stability of Lipase from Wheat Germ Alkaline pH

Sudhindra Rao, K. and Rajendran, S. and Rajeshwara, A. N. and Prakash, V. (1991) Structural Stability of Lipase from Wheat Germ Alkaline pH. Journal of Protein Chemistry, 10 (3). pp. 291-299.

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Abstract

<p align="justify">The present investigation shows the effect of alkaline pH on the structure-function relationship of lipase from wheat germ.There is a 70% decrease in lipase activity at pH 10.0, which decreases to 93% at pH 12.0 as compared to neutral pHactivity (Rajendran et al. 1990). This change is shown to be as a result of loss of a-helical structure with a concomitantincrease in a periodic structure. The results with fluorescence spectra and tyrosyl ionization indicate gradual exposure ofaromatic side chains of tyrosine and tryptophan to the bulk solvent along with the structural changes. The enzyme is in anextended form at alkaline pH with a volume change of -1300 ml/mol as also indicated by increase in reduced viscosity to12.5 ml/g and significant decrease in sedimentation coefficient. The kinetics of the reaction points to a cooper-activepseudo first-order reaction as determined by stopped-flow kinetic analysis in the ultra violet region. The inactivati6nmechanism appears to follow a two-step mechanism of a fast and a slow reaction.</p>

Item Type:	Article
Uncontrolled Keywords:	Lipase wheat germ inactivation structure-function kinetics conformation
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 03 Biochemistry & Molecular Biology > 16 Protein Biochemistry 600 Technology > 08 Food technology > 21 Cereals > 04 Wheat 500 Natural Sciences and Mathematics > 07 Life Sciences > 03 Biochemistry & Molecular Biology > 07 Enzyme Biochemistry
Divisions:	Protein Chemistry and Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	09 Dec 2005
Last Modified:	28 Dec 2011 09:25
URI:	http://ir.cftri.res.in/id/eprint/245

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