Isolation,Purification and Conformational Characterization of Peanut( Arachis Hypogea) Lectin in the Presence of Chaotropes

Abstract

Peanut lectin (PNA) is a plant protein isolated and purified from its natural source Arachis hypogea using biophysical technique called salting out, and analytical technique called size exclusion chromatography, respectively. The isolated lectin was characterised by SDS-PAGE followed by FT-IR study of peanut lectin, which gives the secondary structure of peanut protein. The FTIR data were further strengthened using Circular Dichroism spectropolarimeter. Although peanut lectin comprises majorly of ß-sheet, the protein gave strong negative ellipticity at ~223 nm, a signature of lectin proteins. In addition to circular dichroism study, extrinsic fluorescence study of PNA using 8-Anilino Napthalene-1- Sulphonic acid (ANS) was performed under different conditions such as a range of pH, varying concentration of SDS, and GdnHCl for protein conformational studies. Thermal profiling of PNA was accompanied to study the denaturation pattern of peanut agglutinin, and to know its melting point.