Transglycosylation reaction of a chitinase purified from Nocardia orientalis.

Chitinase from the culture filtrates of Nocardia orientalis IFO 12806 was purified to apparent homogeneity by precipitation with ammonium sulfate followed by successive chromatography on CM-Sephadex and Bio-Gel P-60, and finally by affinity chromatography on a phenyl-Sepharose CL-4B column. The enzyme, which is essentially a hydrolase, also catalyzed a transglycosylation reaction on tetra-N-acetyl-chitotetraose (GlcNAc)4 and penta-N-acetyl-chitopentaose (GlcNAc)5. The enzyme converted the tetrasaccharide into hexa-N-acetyl-chitohexaose (GlcNAc)6 (21%) and di-N-acetyl-chitobiose (GlcNAc)2 (63%) as the major products. The corresponding values for penta-N-acetyl-chitopentaose (GlcNAc)5 were hepta-N-acetyl-chitoheptaose (GlcNAc)7 23% and tri-N-acetyl-chitotriose (GlcNAc)3 59%. The rate of the transglycosylation depended on the temperature, the concentration of substrate and the pH.