文献类型：期刊文献

中文题名：Purification and Characterization of Two Endo-β-1,4-glucanases from Mollusca,Ampullaria crossean

英文题名：Purification and Characterization of Two Endo-β-1,4-glucanases from Mollusca,Ampullaria crossean

作者：Yan-Hong LI[1];Rui GUO[3];Qiu-Yu YIN[1];Ming DING[1];Si-Liang ZHANG[3];Gen-Jun XU[1,2];Fu-Kun ZHAO[1,2]

机构：[1]Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China;[2]College of Life Science, Zhejiang Sci- Tech University, Hangzhou 310018, China;[3]Bioengineering Institute, East China University of Science and Technology, Shanghai 200233, China

年份：2005

卷号：37

期号：10

起止页码：702

中文期刊名：Acta Biochimica et Biophysica Sinica

外文期刊名：生物化学与生物物理学报（英文版）

收录：CSTPCD;;Scopus;北大核心:【北大核心2004】；CSCD:【CSCD2011_2012】；PubMed;

基金：This work was supported by the grants from the National Natural Science Foundation of China (No.30370336);the Major State Basic Research Development Program of China (No.2003CB716006 and No. 2004CB719702);the Creation Foundation from Shanghai Institute

语种：英文

中文关键词：cellulase; endo-β-1,4-glucanase; Ampullaria crossean; purification; substrate specificity

外文关键词：cellulase; endo-β-1,4-glucanase; Ampullaria crossean; purification; substrate specificity

摘要：Two novel endo-β-1,4-glucanases, EG45 and EG27, were isolated from the gastric juice of mollusca, Ampullaria crossean, by anion exchange, hydrophobic interaction, gel filtration and a second round of anion exchange chromatography. The purified proteins EG45 and EG27 appeared as a single band on sodium dodecylsulfate polyacrylamide gel electrophoresis with a molecular mass of 45 kDa and 27 kDa, respectively. The optimum pH for CMC activity was 5.5 for EG45 and 4.4-4.8 for EG27. The optimum temperature range for EG27 was broad, between 50℃ and 60 ℃; for EG45 it was 50 ℃. The analysis on the stability of these two endo-β-1,4-glucanases showed that EG27 was acceptably stable at pH 3.0-11.0 even when the incubation time was prolonged to 24 h at 30 ℃, whereas EG45 remained relatively stable at pH 5.0-8.0. About 85% of the activity of EG27 could be retained upon incubation at 60 ℃ for 24 h. However, less than 10% residual activity of EG45 was detected at 50 ℃. Among different kinds of substrates, both enzymes showed a high preference for carboxymethyl cellulose. EG45, in particular, showed a carboxymethyl cellulose hydrolytic activity of 146.5 IU/mg protein. Both enzymes showed low activities to xylan （from oat spelt） and Sigmacell 101, and they were inactive to p-nitrophenyl-β-D-cellobioside, salicin and starch.
Two novel endo-β-1,4-glucanases, EG45 and EG27, were isolated from the gastric juice of mollusca, Ampullaria crossean, by anion exchange, hydrophobic interaction, gel filtration and a second round of anion exchange chromatography. The purified proteins EG45 and EG27 appeared as a single band on sodium dodecylsulfate polyacrylamide gel electrophoresis with a molecular mass of 45 kDa and 27 kDa, respectively. The optimum pH for CMC activity was 5.5 for EG45 and 4.4-4.8 for EG27. The optimum temperature range for EG27 was broad, between 50℃ and 60 ℃; for EG45 it was 50 ℃. The analysis on the stability of these two endo-β-1,4-glucanases showed that EG27 was acceptably stable at pH 3.0-11.0 even when the incubation time was prolonged to 24 h at 30 ℃, whereas EG45 remained relatively stable at pH 5.0-8.0. About 85% of the activity of EG27 could be retained upon incubation at 60 ℃ for 24 h. However, less than 10% residual activity of EG45 was detected at 50 ℃. Among different kinds of substrates, both enzymes showed a high preference for carboxymethyl cellulose. EG45, in particular, showed a carboxymethyl cellulose hydrolytic activity of 146.5 IU/mg protein. Both enzymes showed low activities to xylan （from oat spelt） and Sigmacell 101, and they were inactive to p-nitrophenyl-β-D-cellobioside, salicin and starch.