Heterologous expression and characterization of Penicillium citrinum nuclease P1 in Aspergillus niger and its application in the production of nucleotides

Nuclease P1 gene (nuc P1)which was cloned from Penicillium citrinum and expressed in A percent niger Bdel4 with the low-background extracellular protein percent The expression strategy of multi-copy nuc P1 in the A percent niger with the linker of 2A peptide was applied to improve the enzyme activity of nuclease P1, the highest activity up to 77 percent6 U/mL percent After Ni-chelate purification, the specific enzyme activity, the optimum temperature and pH were 32 percent4 U/mg, 65 °C and 5 percent3 respectively percent The recombination nuclease P1 was activated by addition of Mg2+, Zn2+ and Cu2+, and inhibited by addition of Ca2+, Fe2+, Mn2+, Ni2+, Co2+, Mg2+, K+ and EDTA percent Furthermore, the enzyme hydrolyses yeast RNA efficiently into 5'- nucleotides percent Through enzymolysis, the highest concentration of nucleotides achieved 15 percent12 mg/mL, and 75U nuclease P1 is suitable amount should be added to the enzymolysis system percent