Purification and Characterization of Crystal Proteins

Abstract

For bioassay of crystal proteins and to study its biochemistry requires pure form of crystals. There are several techniques reported for crystal protein purification from B. thuringiensis including isopycnic centrifugation in cesium chloride, sodium bromide gradient centrifugation, centrifugation through step gradients of ludox, foam flotation-based extraction, carboxymethyl cellulose column chromatography, and gel filtration column chromatography. But the most widely used strategy is discontinuous sucrose density gradient ultracentrifugation. There is an intensive study going on related to the crystal protein endotoxin due to its insecticidal properties which may lead to its commercial production and its use as a biocontrol agent; therefore, there is a need to purify and characterize crystals proteins.