Enzymatic and molecular characterization of α-1,3-glucanase (AglST2) from Streptomyces thermodiastaticus HF3-3 and its relation with α-1,3-glucanase HF65 (AglST1)

The Journal of General and Applied Microbiology

Yoichi Takeda¹  Wasana Suyotha²  Vipavee Cherdvorapong³  Hidehisa Fujiki⁴ 

[1] Department of Applied Chemistry, Faculty of Life Sciences, Ritsumeikan University;Department of Biochemical Engineering, Graduate School of Sciences and Engineering, Yamagata University;Department of Biotechnology, Faculty of Life Sciences, Ritsumeikan University;Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University

关键词: α-1,3-glucan;    α-1,3-glucanase;    characterization;    mycodextranase;    Streptomyces thermodiastaticus HF3-3;   

DOI  :  10.2323/jgam.2018.04.001

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

Extracellular α-1,3-glucanase HF90 (AglST2), with a sodium dodecyl sulfate (SDS)-PAGE-estimated molecular mass of approximately 91 kDa, was homogenously purified from the culture filtrate of Streptomyces thermodiastaticus HF3-3. AglST2 showed a high homology with mycodextranase in an amino acid sequence and demonstrated specificity with an α-1,3-glycosidic linkage of homo α-1,3-glucan. It has been suggested that AglST2 may be a new type of α-1,3-glucanase. The optimum pH and temperature of AglST2 were pH 5.5 and 60°C, respectively. AglST2 action was significantly stimulated in the presence of 5–20% (w/v) NaCl, and 1 mM metal ions Mn2+ and Co2+. On the other hand, it was inhibited by 1 mM of Ag+, Cu2+, Fe2+ and Ni2+. Regarding the stability properties, AglST2 retained more than 80% of its maximum activity over a pH range of 5.0–7.0 at up to 60°C and in the presence of 0–20% (w/v) NaCl. Based on these results, the properties of AglST2 were comparable with those of AglST1, which had been previously purified and characterized from S. thermodiastaticus HF3-3 previously. The N-terminal amino acid sequence of AglST2 showed a good agreement with that of AglST1, suggesting that AglST1 was generated from AglST2 by proteolysis during cultivation. MALDI-TOF mass analysis suggested that AglST1 might be generated from AglST2 by the proteolytic removal of C-terminus polypeptide (approximately 20 kDa). Our investigation thus revealed the properties of AglST2, such as tolerance against high temperature, salts, and surfactants, which have promising industrial applications.

【 授权许可】

Unknown