Method for preparing soluble and active recombinant proteins using pdi as a fusion partner

A method for preparing a recombinant protein is provided to produce the protein stably at a high expression rate and overcome problems of a low solubility of expressed proteins and a low production of active proteins by satisfying a high expression rate of a target protein, improved production of a soluble protein, and protein folding into an active form using protein disulfide isomerase(PDI) as a fusion partner. A method for preparing a soluble and active recombinant protein comprises the steps of: (a) inserting a gene encoding PDI as a fusion partner into a vector; and (b) ligating a gene encoding the target protein with the gene encoding the PDI, wherein the target protein is selected from the group consisting of tissue-type plasminogen activator, enterokinase, proinsulin, batroxobin, bone morphogenetic protein, angiogenin, tobacco etch virus protease, interleukin-2, granulocyte colony stimulating factor and tumor necrosis factor. The method further comprises a step of transforming a host cell with a recombinant expression vector including a fused gene where the gene encoding the target protein is ligated with the gene encoding the PDI. Further, the PDI protein removes a ribosome binding site through deforming gene.