The protein encoded by human CD276 gene belongs to the immunoglobulin superfamily, and thought to participate in the regulation of T-cell-mediated immune response. Studies show that while the transcript of this gene is ubiquitously expressed in normal tissues and solid tumors, the protein is preferentially expressed only in tumor tissues. Additionally, it was observed that the 3′ UTR of this transcript contains a target site for miR29 microRNA, and there is an inverse correlation between the expression of this protein and miR29 levels, suggesting regulation of expression of this gene product by miR29.

Full-length extracellular domain of human CD276 gene (29 – 466 aa) was constructed with 29 N-terminal T7/His tag and expressed in E. coli as inclusion bodies. The final product was refolded using a unique “temperature shift inclusion body refolding” technology and chromatographically purified.