树鼩载脂蛋白CI蛋白质结构分析

Analysis of the Protein Structure of Tree Shrew Apolipoprotein CI

为了获得树载脂蛋白CI的蛋白质结构信息，利用相应的计算机软件及改良的Chou等方法，对从构建的树肝组织cDNA文库中克隆出的载脂蛋白CIcDNA序列进行了分析和比较，并对编码的蛋白质氨基酸序列及其二级结构、亲疏水性进行了分析和预测。结果表明，克隆出的树载脂蛋白CIcDNA序列（新基因已被GenBank接受）由380个核苷酸构成，编码翻译88个氨基酸的载脂蛋白CI前体（含26个氨基酸构成的信号肽和62个氨基酸组成的成熟蛋白），并推测出该蛋白的功能域、蛋白质的二级结构及C末端有一明显的疏水区。结果提示：树载脂蛋白CI的疏水性及结合脂质的能力强于人的载脂蛋白CI。

Aim To obtain the protein structure deduced from tree shrew (TS) apolipoprotein CI (apo CI) cDNA se-quence.Methods Using Chou's method modified and some related computer softs, not only TS apo CI cDNA sequence cloned in a constructed cDNA library of TS liver tissue was analyzed and compared with those of other species, but also the deduced amino acid (AA) sequence, its secondary structure and hydrophobility of the protein were determined and predicted.Results TS apo CI cDNA sequence consists of 380 nucleotides encoding an 88 AA apo CI precursor (a 26AA signal peptide and a 62 AA mature protein. The function domains of the protein were predicted to locate in two regions of 13~26 AA and 32~57 residues.The secondary structure may contain several kindsof conformations. There is an obvious hydrophobic region at the C-terminal of the amino acid sequence.Conclusion The present results shows TS apo CI is more hydrophobic and may have a stronger ability of binding lipids than human apo CI.