GENE ENGINEERING ARGININE DEIMINASE REFORMED THROUGH SITE DIRECTED MUTAGENESIS

摘要

A strain of gene engineering arginine deiminase reformed through site directed mutagenesis, relating to the technical field of gene engineering. The amino acid sequence is SEQ ID No.1, and the 264 site glycine in the amino acid sequence of the arginine deiminase reformed through site directed mutagenesis mutates into proline relative to the amino acid sequence of the natural arginine deiminase. Compared to a wild enzyme, the effective pH action range of the mutant arginine deiminease is expanded to a certain degree, and in particularly, the mutant arginine deiminease has good enzyme activity at the physiological pH value of 7.4. The mutant enzyme has the high stability under the pH value of 5.5-7.5 along with the broadening of the effective pH action range. Therefore, the problems of low enzyme activity and short half-life in vivo under physiological conditions of the clinical applications of the arginine deiminase in tumor treatment are solved, and good conditions are created for the application of the arginine deiminase and the coding gene thereof in clinical treatment.