Extraction and separation of water-soluble proteins from Bacillus thuringiensis-transgenic and non-transgenic maize species by CZE.

A new method for extraction and CZE separation and characterization of water-soluble proteins (albumin fraction) from Bacillus thuringiensis-transgenic and non-transgenic maize varieties was developed. Protein content in the extracts from maize flours was estimated by UV-absorbance at 280 nm and Lowry protein assay. Protein extracts were analyzed by CZE in four acidic BGEs (100 mM H(3)PO(4), 50 mM Tris, pH 2.25; 500 mM acetic acid, pH 2.6; 200 mM formic acid, 200 mM acetic acid, pH 2.05; 200 mM iminodiacetic acid, pH 2.26) using a homemade CZE device equipped with bare fused silica capillary and UV-absorption detector at 206 nm. Among the tested BGEs, the best resolution of extracted proteins was achieved in isoelectric BGE, 200 mM iminodiacetic acid, pH 2.26. Well-resolved components of protein extracts were characterized by effective electrophoretic mobilities and corrected (migration times normalized) peak areas. Significant qualitative and quantitative differences in CZE-UV profiling were found. This approach can potentially be used to distinguish the B. thuringiensis variety from the wild maize in an easy and straightforward way.