Method for the secretory production of heterologous protein in escherichia coli

A method for producing a recombinant protein with improved extracellular secretion efficiency of a heterologous protein in E. coli, comprising the following steps:

• 1) constructing a gene construct comprising a polynucleotide encoding a recombinant protein in which a signal sequence peptide comprising the polypeptide represented by SEQ. ID. NO. 3, and a heterologous protein fused to C-terminal of the said signal sequence peptide are arranged stepwise;
• 2) constructing an expression vector to which the gene construct of step 1) is operably linked;
• 3) preparing a transformant by transfecting a host cell with the expression vector of step 2);
• and
• 4) obtaining the recombinant protein after inducing the expression of the recombinant protein by culturing the transformant of step 3).

A method for producing a heterologous protein in its original form comprising the following steps:

• 1) constructing a recombinant expression vector to which a gene construct comprising a polynucleotide encoding the recombinant protein in which a signal sequence peptide comprising the polypeptide represented by SEQ. ID. NO. 3, a protein restriction enzyme recognition site, and a heterologous protein are arranged in that order is operably linked;
• 2) constructing a transformant by transfecting a host cell with the recombinant expression vector of step 1);
• 3) inducing the expression of the recombinant protein by culturing the transformant of step 2);
• 4) separating the recombinant protein from the culture solution of step 3);
• and,
• 5) separating the original form of the heterologous protein after digesting the recombinant protein prepared in step 4) with a protease that is able to cut the protease recognition site.