The invention relates to an anti-autotomy and high-specific-activity AspN
enzyme mutant as well as a coding
gene and application thereof. The invention aims to solve the problems that the
wild type AspN
enzyme is easy to self-dissect and inactivate and is poor in stability. The
mutant is obtained by mutating one or more
aspartic acid sites in the 94th site, the 108th site, the 132 site, the 141 site, the 182 site and the 184 site on the basis of an
amino acid sequence shown in SEQ ID NO: 1. The preferred mutations include D182N, D182A, D182V, D132N, D132Q, D184E, D94G, D108T, D141G, and a combination of D182N and D132N. Compared with a
wild type, the
specific activity and / or the
enzyme activity
retention rate of the
mutant are / is remarkably improved. The stability and
catalytic efficiency of the AspN enzyme are effectively improved, and the method has good application prospects in
protein sequencing, polypeptide preparation and
mass spectrometry.