HIV核心抗原p24原核系统的高效表达、纯化及活性鉴定

目的　在原核表达系统中对HIVp2 4抗原基因进行克隆和高效表达、纯化并鉴定其活性。方法　利用PCR技术从HIV-1全基因质粒 (B2N)中扩增p2 4抗原基因 ,并克隆入T载体中。通过酶切消化后连接到表达载体pRSET上 ,用此连接产物转化大肠埃希菌BL2 1,经IPTG诱导 ,表达p2 4抗原。利用固定化金属离子 (Ni2 )配体亲和层析技术从表达蛋白中纯化目的蛋白。并运用双酶切技术、SDS-PAGE电泳、WesternBlot(WB)及ELISA法分别对插入基因片段的正确性、表达产物的活性及特异性进行检测。结果　PCR产物约为 6 90bp ,与预期p2 4抗原全基因片段大小一致。重组质粒T-p2 4和pRSET-p2 4经BamHⅠ和HindⅢ双酶切 ,其插入的外源基因片段均为 6 90bp。将纯化前与纯化后的蛋白作SDS PAGE电泳 ,均可见一条约 2 4× 10 3的外源基因表达带 ,与计算的相对分子质量相符。经WB和ELISA试验 ,证明基因工程表达的p2 4抗原具有较高的特异性及活性。结论　成功构建了HIVp2 4表达载体pRSET-p2 4 ,并在原核细胞中高效表达 ,其表达产物具有良好的特异性及活性

Prokaryotic expression and purification of human immunodeficiency virus p24 antigen

OBJECTIVE: To express and purify the HIV p24 gene in E. coli cells, and identify p24 antigen activity. METHODS: The full length gene fragment of HIV p24 was amplified by PCR and inserted into the pRSET vector in order to construct the pRSET-p24 recombined vector. After transforming into E. coil, the purified p24 protein was prepared by metal-ligand affinity chromatography (IMAC). The accuracy of inserted gene and activity, specificity of HIV p24 proteins were detected by two enzymes digestion technology, SDS-PAGE, Western Blot (WB) and ELISA. RESULTS: The length of the HIV p24 gene fragment was 690 bp after digesting the recombinant plasmid T-p24 and pRSET-p24 with BamH I and Hind III. The expressed proteins had a single expected band of about 24 x 10(3) in SDS-PAGE. The specificity and activity of p24 protein were tested by WB and ELISA. CONCLUSION: The HIV p24 sequence from HIV-1 gene plasmid hasbeen expressed in E. coil. This protein possessed good specificity and activity.