The invention belongs to the technical field of
biology, and provides a mutated Cas9
protein which has the activity of a cleavage
gene, the
mutation of the mutated Cas9
protein is an
antigen epitope capable of reducing
immunogenicity, and the mutated Cas9
protein is selected from A144G, E146G, E147G, D161G, G162A, R269G, D270A, E271G, N272G, E273G, P294A, T295A, D309A, P321A, E322G, A337G, R338G, T369A, E378G or short
peptide 200-208 TYIDLLETR. The invention further discloses the
antigen epitope of the SaCas9 protein and application of the SaCas9 protein in
gene editing. The dominant
antigen epitope has no influence on SaCas9
protein cleavage function activity, and the
human body immune response problem possibly induced by a
CRISPR-Cas9
system can be improved through deimmunization transformation of the Cas9 protein.