A study on constructing and screening of multi-copy pdgf recombinant Pichia pastoris clones producing high yield of PDGF-BB (platelet derived growth factor BB)
Keywords:Pichia pastoris, multi-copy clone, platelet-derived growth factor BB, yeast.
Platelet-derived growth factor-BB has been approved by US Food and Drug Administration-FDA for the treatment of neuropathic ulcers. Since the number of diabetic patients has increased rapidly, it is necessary to study the production of PDGF-BB with low cost for treatment. Among the expression systems used for human recombinant protein expression, Pichia pastoris is the remarkable one with many advantages. Multiple integrated copies of target gene may give advance in driving up expression level of target protein. In this study, we succeeded in constructing and screening two yeast clones, which carry multi-copy of pdgf target gene. The two multi-copy yeast clones were subjected indetermination of PDGF expression level and compared to single-copy yeast clones. Our results showed that multi-copy pdgf yeast clones have higher level expression of target protein. PDGF produced by the multi-copy pdgf yeast clones accounted for over 50% of total secretory protein, and was folded in dimer form, which is necessary for performing biofunction in wound healing.