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Hybrid glucanases with multiple catalytic functions created by protein domain fusion
Author(s) -
Lin YuShiun,
Shyur LieFen
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a898-a
Subject(s) - glucanase , laminarin , brewing , chemistry , glycoside hydrolase , tetrasaccharide , glucan , glycosidic bond , carbohydrate binding module , biochemistry , food science , enzyme , polysaccharide , fermentation
Fibrobacter succinogenes 1,3‐1,4‐β‐D‐glucanase (Fsβ‐glucanase, lichenase) specifically cleavages β‐1,4‐glycosidic bonds in 3‐ O ‐substituted glucopyranose units of β‐glucan, yielding mainly trisaccharide and tetrasaccharide. Lichenase is of important biotechnological aids in the brewing industry for reducing viscosity during mashing, and in animal feed industry for improving digestibility of barley‐based diets. Thermotoga maritima 1,3‐β‐glucanase (laminarinase) composes of a catalytic domain (T m lam) flanked by two domains of carbohydrate‐binding module family 4 (CBM4), namely T m B 1 and T m B 2 at its N‐ and C‐termini, respectively. Fsβ‐Glucanase possesses low activity for substrate laminarin. The objective of this study is to create hybrid glucanases for the purpose of improving the catalytic properties and the industrial usages of Fsβ‐glucanase. In this study five hybrid proteins were created using functional domain fusion, namely T m B 1 ‐F s β‐glucanase, Fsβ‐glucanase‐T m B 2 , T m B 1 ‐F s β‐glucanase‐TmB 2 , T m lam‐F s β‐glucanase and Fsβ‐glucanase‐T m lam, and have been successfully expressed in E. coli system. Our results indicate that hybrid glucanases were structurally more stable than the parental Fsβ‐glucanase against heat or 8 M urea treatment, suggesting that the thermo‐stable characteristics of Tm‐laminarinase has been incorporated into Fsβ‐glucanase. Potential biotechnological applications of the hybrid enzymes created in this study are under evaluated. This work is supported by National Science Council of Taiwan.