CTLA4胞外区蛋白在GS115酵母中的表达和活性鉴定

Expression and activity of CTLA4 extracellular domain in the yeast GS115

目的 获取具有生物学活性的CTLA4胞外区蛋白。方法 构建CTLA4胞外区 (CTLA412 5)蛋白的酵母表达载体 ,在GS115酵母细胞中表达。通过硫酸铵粗分离和离子交换层析等 ,获取纯化的目的蛋白 ,并在CTLL2细胞中鉴定活性。结果 质粒在GS115酵母中可较高水平地表达CTLA4胞外区蛋白。经纯化后的蛋白可抑制IL 2刺激的CTLL2细胞的增殖。结论 GS115酵母可高效表达具有生物学活性的CTLA4胞外区蛋白。

Objective To obtain the biologically-active protein of the cytotoxic T lymphocyte associated antigen 4 (CTLA4) extracellular domain. Methods The protein of CTLA4 extracellular domain (CTLA4 125 ) was generated through the construction of yeast vector expressing CTLA4 extracelluar domain and its expression in yeast GS115. The protein was purified by rough separation with ammonium sulfate sedimentation and ion-exchange chromatography. The activity of the protein was assayed by detecting its inhibitory effect on the proliferation of CTLL2 cells induced by IL-2. Results The plasmid encoding the CTLA4 extracellular domain expressed the target protein in high level in the yeast Gs115. The purified protein inhibited the proliferation of CTLL2 cells stimulated by IL-2. Conclusion Yeast GS115 can highly express in the protein of CTLA4 extracellular domain with biological activity.