Purification and characterization of chitin deacetylase from Penicillium oxalicum SAE_M-51

摘要

Chitin deacetylase (CDA) with a molecular mass of 53 kDa was purified from Penicillium oxalicum SAE_M-51. Optimal temperature and pH of the purified enzyme were 50 ℃ and 9.0 respectively. Activation energy (E_(a,d)), free energy (ΔG_d*), enthalpy (ΔH_d*) and entropy (ΔS_d*) for enzyme denaturation at optimal temperature were 114.72 kJ mol~(-1),97.86 kJ mol~(-1), 112.04 kJ mol~(-1), 43.93 J mol~(-1) K~(-1), respectively. Enzyme had the half life of 693.10 min at its optimum temperature. It had notably deacetylated glycol chitin and chitin oligomers having degree of polymerization of more than four. Increased enzyme activity was observed with metal ions mainly Cu~(2+) and Co~(2+). No inhibition of the enzyme was observed by the end product i.e. acetate (0-60 mM). Far-UV CD spectroscopic analysis revealed presence of 56.26% α and 15.63% β-helical structures. Significant homology of the enzyme was observed with CDAs from fungal and yeast strains.