Study On Glycosylation And Acetylation Of CBH? From Trichoderma Reesei

Lignocellulosic biomass,the most abundant organic molecule on earth,is sustainable but has not been fully exploited and utilized yet,the effective generation of fermentable sugar and cost-competitive production from cellose is one of effective ways to solve resource and environment problems.Trichoderma reesei is widely used in the industrial cellulases production.Moreover,the CBH?(cellobiohydrolase I)from Trichoderma reesei is the major component of cellulase systems.Glycosylation and acetylation are ubiquitous posttranslational modifications of protein,with considerable functions in molecular and cell biology.To date,the glycosylation of CBH? from Trichoderma reesei have attracted much attention,including Nand O-glycans,while acetylation of CBH? have not reported research.In this work,we have identified three glycosylation sites,which are T397,T400 and N401 and three acetylation sites,which are T133,S165 and K183 of CBH? through mass spectrum(MS)analysis,those glycosylation and acetylation modifications were removed via site-directed mutagenesis.Further,the hydrolytic activity of viriants of Tr_T397A/T400A/N401Q,Tr_T133A/S165A/K183A,Tr_T133A,Tr_S165A,Tr_K183A were detected.Overall,we found the degradation efficiency of Tr_T397A/T400A/N401Q and Tr_T133A/S165A/K183A on Avicel,DCCR and Filter paper were not significantly affected by the lack of O-glycan or acetyl groups,while the Tr_T133A,Tr_S165A and Tr_K183A mutants exhibit a higher hydrolytic efficiency than Tr control in this study.