Promotion of Extracellular Activity of Cellobiohydrolase I from Trichoderma reesei by Protein Glycosylation Engineering in Saccharomyces cerevisiae
The State Key Laboratory of Microbial Technology, Shandong University, Shan Da Nan Road 27#, Jinan, 250100, China
- *Corresponding Author:
- Xiaoming Bao
The State Key Laboratory of Microbial Technology
Shan Da Nan Road 27#, Jinan, 250100, China
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Received date: May 15, 2014; Accepted date: June 18, 2014; Published date: July 01, 2014
Citation: Xu L, Shen Y, Hou J, Tang H, Wang C, et al. (2014) Promotion of Extracellular Activity of Cellobiohydrolase I from Trichoderma reesei by Protein Glycosylation Engineering in Saccharomyces cerevisiae. Curr Synthetic Sys Biol 2:111. doi: 10.4172/2332-0737.1000111
Copyright: © 2014 Xu L, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The N-glycosylation in Saccharomyces cerevisiae is of the high-mannose type, which affects the activity of the secreted heterologous glycoproteins. Cellobiohydrolase I (Tr-Cel7A) from Trichoderma reesei, is thus hyperglycosylated when expressed in S. cerevisiae. In the present work, three genes encoding the endogenous mannosyltransferases, Och1p, Mnn9p and Mnn1p, involved in glycoprotein processing in the S. cerevisiae Golgi apparatus, were individually or combinatorially disrupted to investigate the effect of the glycosylation extent on the activity of the secreted Tr-Cel7A. The glycosylation of the recombinant Tr-Cel7A was decreased and its extracellular activity was increased in all the deletion mutants. The simultaneous deletion of och1 and mnn1 has the most improvement on extracellular Tr-Cel7A activity. After expressed the α-1,2-mannosidase (Tr-Mds1p) from T. reesei in mnn1Δ/och1Δ strain, the Tr-Cel7A activity was further increased up to 320 ± 8% higher than that of the wild type strain. Such activity improvement was due not only to the higher secretion yield but also to the increased specific activity resulted from the changes in glycosylation. The results thus indicated that protein glycosylation engineering in S. cerevisiae was an effective approach to improve the extracellular activity of Tr-Cel7A.