Open AccessThe N‐terminal cellulose‐binding domain of EGXA increases thermal stability of xylanase and changes its specific activities on different substrates
Author(s) -
Ding Ming,
Teng Yigang,
Yin Qiuyu,
Zhao Jie,
Zhao Fukun
Publication year - 2008
Publication title -
acta biochimica et biophysica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.771
H-Index - 57
eISSN - 1745-7270
pISSN - 1672-9145
DOI - 10.1111/j.1745-7270.2008.00481.x
Subject(s) - xylanase , carboxymethyl cellulose , recombinant dna , cellulose , biochemistry , xylan , enzyme , chemistry , thermal stability , peptide , sodium , organic chemistry , gene
A full‐length EGXA enzyme from a mollusk, Ampullaria crossean , was cloned into pFastBac vector and then heterogeneously expressed in insect Tn5 cells. Its natural N‐terminal signal peptide worked well in the insect Tn5 cells. The recombinant EGXA was a 63 kDa protein and had active endo‐β‐1,4‐glucanase ( EC 3.2.1.4 ) and e ndo‐β‐1,4‐xylanase ( EC 3.2.1.8 ). The sp ecific activity of endo‐β‐1, 4‐xyla nase was higher than in the EGX, which was purified from the stomach tissues of Ampullaria crossen. The N‐terminal cellulose‐binding domain of EGXA made it bind to cellulose and xylan more efficiently. This cellulose‐binding domain also increased the thermal stability of this recombinant enzyme and decreased the recombinant EGXA's specific activities on p‐nitrophenyl‐β‐D‐cellobioside and sodium carboxymethyl cellulose.