Beta glucosidase from Bacillus polymyxa is activated by glucose-6-phosphate.

Archives of biochemistry and biophysics

PubMedID: 26116788

Weiss PH, Álvares AC, Gomes AA, Miletti LC, Skoronski E, da Silva GF, de Freitas SM, Magalhães ML. Beta glucosidase from Bacillus polymyxa is activated by glucose-6-phosphate. Arch Biochem Biophys. 2015;.
Optimization of cellulose enzymatic hydrolysis is crucial for cost effective bioethanol production from lignocellulosic biomass. Enzymes involved in cellulose hydrolysis are often inhibited by their end-products, cellobiose and glucose. Efforts have been made to produce more efficient enzyme variants that are highly tolerant to product accumulation; however, further improvements are still necessary. Based on an alternative approach we initially investigated whether recently formed glucose could be phosphorylated into glucose-6-phosphate to circumvent glucose accumulation and avoid inhibition of beta-glucosidase from Bacillus polymyxa (BGLA). The kinetic properties and structural analysis of BGLA in the presence of glucose-6-phosphate (G6P) were investigated. Kinetic studies demonstrated that enzyme was not inhibited by G6P. In contrast, the presence of G6P activated the enzyme, prevented beta glucosidase feedback inhibition by glucose accumulation and improved protein stability. G6P binding was investigated by fluorescence quenching experiments and the respective association constant indicated high affinity binding of G6P to BGLA. DATA
reported here are of great impact for future design strategies for second-generation bioethanol production.