| abstract |
The present invention provides an expression vector, which includes: (a) a nucleotide sequence X that encodes a protein tag; (b) a nucleotide sequence that encodes a Smt3 protein; (c) restriction site, wherein the expression vector, upon insertion of a target DNA fragment via the restriction site, expresses a fusion protein in host cell. Cleaving the fusion protein by X-U1p1 protease-X produces the native protein. The present invention also provides a kit of purifying a protein of interest through single column, comprising: (a) providing a vector containing a protein tag X and Smt3 protein sequence, (b) inserting target protein sequence into the vector via restriction site, (c) the vector was transforming into host cells to produce fusion protein, (d) loading the fusion protein to a protein-tag affinity column to allow binding of the fusion protein to the column, (e) incubating the column with X-U1p1 protease-X and eluting the native target protein from the column. |