2015 年 62 巻 4 号 p. 153-157
Chitin oligosaccharide deacetylase (COD) is an enzyme that generates β-N-acetyl-D-glucosaminyl-(1,4)-D-glucosamine from N,N′-diacetylchitobiose. COD has been found only in species of Vibrio bacteria. However, a homology search in the sequence databases revealed that Shewanella woodyi ATCC51908 also encodes a protein with sequence similarity to COD. Analysis of the deduced amino acid sequence of the S. woodyi COD (Sw-COD) confirmed that the protein contains the same motifs as CODs from Vibrio bacteria. The COD-encoding gene, which includes a signal sequence, was cloned from the chromosomal DNA of S. woodyi, the expression plasmid containing this gene was constructed, and then the plasmid was introduced into Escherichia coli HMS174(DE3) cells. The recombinant Sw-COD (Sw-rCOD) was produced in culture medium with the aid of the signal peptide and purified from culture supernatant. The properties of Sw-rCOD (substrate specificity, optimal pH, etc.) were similar to those of the CODs from Vibrio bacteria.
