A comparison of protein crystal subunit sizes in Bacillus thuringiensis

Abstract

Gel electrophoresis was used to determine the number and size of the subunits present in the protein crystals from 16 strains of B. thuringiensis. The calculated MW fell into 3 major categories whose crystals exhibited the following protein banding patterns: type I, high MW only (140,000-160,000); type II, both high MW and medium MW (60,000 and 150,000); and type III, low MW only (40,000-50,000). Interestingly, the type I and type II crystals were the expected bipyramidal diamonds whereas the type III crystals possessed a previously unreported tetrahedral shape.