The invention relates to the technical field of
biology, in particular to a recombinant
fusion protein,
polynucleotide for coding the recombinant
fusion protein, a
recombinant expression plasmid containing the
polynucleotide, an engineered recombinant host
cell and a method for preparing target polypeptide by using the recombinant
fusion protein. The recombinant fusion
protein comprises tag polypeptide-target polypeptide-(
linker 1-
linker x-
linker 2-target polypeptide) n from N terminal to C terminal, x is the number of linkers, x is 0 or 1, n is a positive integer not less than 1, the tag polypeptide is SEQ ID NO.1 or SEQ ID NO.2, the linker 1 contains a Kex2
protease enzyme cutting site and a
carboxypeptidase B
enzyme cutting site, and the linker 1 contains a Kex2
protease enzyme cutting site and a
carboxypeptidase B enzyme cutting site. And the connecting
peptide 2 contains a WELQ
protease enzyme cutting site. The recombinant fusion
protein disclosed by the invention is expressed in an inclusion body form, the synthesis process is simplified, the target polypeptide can be prepared with high yield and high purity by using the recombinant fusion
protein disclosed by the invention, and the production cost can be reduced from multiple dimensions.