Fragmentation and Characteristics of Recombinant Endochitinase Expressed in Escherichia Coli

Wei-Ming Chen ； Gen-Hung Chen ； Shann-Tzong Jiang

《Journal of Marine Science and Technology》 20卷4期 (2012/08) Pp. 369-375

https://doi.org/10.6119/JMST-011-0225-1

並列摘要

A recombinant endochitinase fused with hexahistidine (rEC-H) was expressed and characterized. After Ni affinity chromatography, the recovery, purification-fold and specific activity of rEC-H were 88.8%, 13.4 and 142.1 U/mg, respectively. The purified rEC-H had optimal pH and temperature at pH 7.5 and 60°C, respectively and was stable at pH 4.0-9.0 and ＜50°C. It was activated by Ca(superscript 2+), Sr(superscript 2+), Ba(superscript 2+), Co(superscript 2+) and β-mercaptoethanol, but highly inhibited by Cu(superscript 2+), Hg(superscript 2+) and SDS. The thiol group may play an important role on rEC-H and rEC-H may easily be destructed when hydrophobic interaction is disrupted by sodium dodecyl sulfate. The molecular mass was lower than that of expected due to cleavage at 2 specific sites, 33Ala-34Asp and 472Glu-473Leu within rEC-H, suggesting the fragmentation of rEC-H occurred during expression.

並列關鍵字

expression ； endochitinase ； Escherichia coli ； proteolysis

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