新基因GIDRP88编码蛋白质电泳异常迁移的研究

通过制备GIDRP88蛋白质特异的多克隆抗体对GIDRP88基因体外翻译的样品进行检测，结果观察到GIDRP88蛋白质的电泳迁移率随凝胶中丙稀酰胺浓度的改变而发生改变，表明其存在异常迁移．生物信息学分析发现GIDRP88蛋白质一级结构电荷分布不均．为进一步研究电荷分布对其迁移率的影响，分别克隆了GIDRP88基因中电荷分布相对均匀的C端区段A(编码222个氨基酸残基)，以及有多余负电荷的中部区段B(编码182个氨基酸残基)，在大肠杆菌中诱导表达后，发现A区段表达肽段迁移正常而B区段表达肽段表观分子量比预期偏大32．9％．表明电荷分布不均影响了GIDRP88蛋白质在SDS-PAGE上的迁移．

Anomalous Migration Phenomena of the Protein of a Novel Gene GIDRP88

A discrepancy existed between the calculated molecular weight(87.9kD) for the protein of a novel gene GIDRP88 and its apparent molecular weight on SDS-PAGE(125.97kD).The variable electrophoretic mobility for GIDRP88 protein was characterized at different acrylamide concentrations. Two segments of GIDRP88, one(A) possessing nearly even charge distribution for acidic and basic residues and the other (B) containing excess negative charge , were cloned. The A clone expressed a peptide segment which exhibited the usual mass/migration relationship, whereas the molecular weight estimated by SDS-PAGE for the peptide segment of the B clone diverged 32.9% from the calculated molecular weight . These results indicate that the localized high negative charge on certain segments of GIDRP88 might be responsible for the anomalous migration of it in SDS-PAGE.