氨基酸组成对胶原与整合素α2β1结合能力的影响

Effect of Amino Acid Composition on the Binding Capacity of Collagen to Integrinα2β1

以不同物种来源的胶原作为研究对象,测定各胶原的氨基酸组成,利用酶联免疫吸附测定实验和细胞黏附实验研究各胶原样本与整合素α2β1及HT1080细胞的结合能力,探讨氨基酸组成对胶原配体-细胞受体α2β1结合能力的影响。结果表明,不同来源的胶原样本在与整合素α2β1和HT1080细胞结合能力方面均存在显著差异,其中,哺乳动物胶原的结合能力明显大于鱼类胶原。氨基酸组成对胶原-整合素α2β1及HT1080细胞结合能力的影响具有相似性,其结合能力均与羟脯氨酸、不带电荷极性氨基酸、亚氨基酸含量和羟基化率呈正相关,而与谷氨酸、甘氨酸、带电荷极性氨基酸和酸性氨基酸含量呈负相关(P<0.01)。同时对胶原与整合素α2β1高亲和力结合位点的信息氨基酸含量进行多元逐步回归分析,建立了羟脯氨酸和精氨酸含量与胶原-整合素α2β1结合能力之间的数学模型,经验证,该数学模型具有较好的预测准确性。

The amino acid composition of collagens from different animal species was determined and their binding capacities to integrinα2β1 and HT1080 cells were studied by enzyme-linked immunosorbent assay(ELISA)and cell adhesion experiments.Furthermore,the effect of amino acid composition on collagen binding toα2β1 was discussed.The results showed that there were significant differences among the binding capacities of collagens from different animal species to integrinα2β1 and HT1080 cells,and the binding capacity of mammalian collagen was higher than that of fish collagen.The effects of amino acid composition on the binding capacities of collagen to integrinα2β1 and HT1080 cells were similar.The binding capacities were positively correlated with the contents of hydroxyproline,polar uncharged amino acids,imino acids and the degree of hydroxylation of proline,but negatively correlated with the contents of glutamate,glycine,polar charged amino acids and acidic amino acids(P<0.01).Based on the content of informative amino acids at the high-affinity binding site between collagen and integrinα2β1,a mathematical model between the contents of hydroxyproline and arginine and collagen-integrinα2β1 binding was established by multivariate step-wise regression analysis,which had good predictive accuracy.