supplementing with non-glycoside hydrolase proteins enhances enzymatic deconstruction of plant biomass补充与non-glycoside水解酶蛋白增强了植物的酶解构.pdfVIP

Supplementing with Non-Glycoside Hydrolase Proteins Enhances Enzymatic Deconstruction of Plant Biomass Xiaoyun Su1,2, Jing Zhang1,2,3, Roderick I. Mackie1,2,3, Isaac K. O. Cann1,2,3,4* 1 Energy Biosciences Institute, University of Illinois, Urbana, Illinois, United States of America, 2 Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America, 3 Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America, 4 Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America Abstract The glycoside hydrolases (GH) of Caldicellulosiruptor bescii are thermophilic enzymes, and therefore they can hydrolyze plant cell wall polysaccharides at high temperatures. Analyses of two C. bescii glycoside hydrolases, CbCelA-TM1 and CbXyn10A with cellulase and endoxylanase activity, respectively, demonstrated that each enzyme is highly thermostable under static incubation at 70uC. Both enzymes, however, rapidly lost their enzymatic activities when incubated at 70uC with end-over- end shaking. Since crowding conditions, even at low protein concentrations, seem to influence enzymatic properties, three non-glycoside hydrolase proteins were tested for their capacity to stabilize the thermophilic proteins at high temperatures. The three proteins investigated were a small heat shock protein CbHsp18 from C. bescii, a histone MkHistone1 from Methanopyrus kandleri, and bovine RNase A, from a commercial source. Fascinatingly, each of these proteins increased the thermostability of the glycoside hydrolases at 70uC during end-over-end shaking incubation, and this property translated into increases in hydrolysis of several substrates including the bioenergy feedstock Miscanthus. Furthermore, MkHistone1 and RNase A also altered the initial products released from the cello-oligosaccha