Gene Cloning, Overexpression, and Characterization of a Xylanase from Penicillium sp. CGMCC 1669

Abstract

A xylanase-encoding gene, xyn11F63, was isolated from Penicillium sp. F63 CGMCC1669 using degenerated polymerase chain reaction (PCR) and thermal asymmetric interlaced (TAIL)-PCR techniques. The full-length chromosomal gene consists of 724 bp, including a 73-bp intron, and encodes a 217 amino acid polypeptide. The deduced amino acid sequence of xyn11F63 shows the highest identity of 70% to the xylanase from Penicillium sp. strain 40, which belongs to glycosyl hydrolases family 11. The gene was overexpressed in Pichia pastoris, and its activity in the culture medium reached 516 U ml(-1). After purification to electrophoretic homogeneity, the enzyme showed maximal activity at pH 4.5 and 40 degrees C, was stable at acidic buffers of pH 4.5-9.0, and was resistant to proteases (proteinase K, trypsin, subtilisin A, and alpha-chymotrypsin). The specific activity, K (m), and V (max) for oat spelt xylan substrate was 7,988 U mg(-1), 22.2 mg ml(-1), and 15,105.7 micromol min(-1) mg(-1), respectively. These properties make XYN11F63 a potential economical candidate for use in feed and food industrial applications.

Recombinant exochitinase of the thermophilic mould Myceliopthora thermophila BJA: Characteristics and utility in generating N‐acetyl glucosamine and in biocontrol of phytopathogenic fungi

“…The enzyme is strongly inhibited by Ni 4+ , Cd 2+ , and Hg 2+ . The inhibition by Hg 2+ indicates the vital role of acidic amino acids and tryptophan residues in enzyme catalysis and maintenance of catalytic conformation of the protein, respectively . The metal ion chelators EDTA and EGTA had no effect on enzyme activity suggesting that metal ions are not essential for the chitinase activity.…”

Molecular characterization of a cold-active recombinant xylanase from Flavobacterium johnsoniae and its applicability in xylan hydrolysis

“…Significant inhibition of xylanase activity by SDS and DTAB (0.5%) was recorded in Penicillium sp. CGMCC1669 (Liu et al, 2010) and G. mesophila KMM 241 (Guo et al, 2009). …”

Cloning and expression of acidstable, high maltose-forming, Ca2+-independent α-amylase from an acidophile Bacillus acidicola and its applicability in starch hydrolysis

“…Further, Hg 2? is known to oxidize indole ring and to interact with aromatic ring present in tryptophan (Zhang et al 2007;Liu et al 2010). NBS exerted very strong inhibitory action as in b-D-xylanase of B. halodurans, indicating the catalytic role of tryptophan (Kumar and Satyanarayana 2011).…”