Characterization of a Beta-glucosidase Aggregating Factor Responsible for the Null Beta-glucosidase Phenotype in Maize (Zea mays L.)
Interestingly, BGAF binds to both maize beta-glucosidase isozymes (Glu1 and Glu2), but does not bind to their sorghum homolog Dhurrinase-1 (Dhr1; Sorghum beta-glucosidase), that shares 70% sequence identity with Glu1 and Glu2. Therefore, these proteins provide an excellent system to study functional differences at nonconserved residues and elucidate the mechanism of enzyme aggregation and insolubility. By examining the behavior of beta-glucosidase chimeras in binding assays, I demonstrate that BGAF binding is conformation dependent, highly specific, and reminiscent of antigen-antibody interactions. Additionally, I have identified two disparate polypeptide segments in the primary structure of the maize beta-glucosidase isozyme Glu1 that form a BGAF binding site in the tertiary structure of the enzyme.
Advisor:William Newton; Charles Rutherford; Asim Esen
School Location:USA - Virginia
Source Type:Master's Thesis
Date of Publication:04/28/2000