Effect of Amino Acid Composition on the Binding Capacity of Collagen to Integrin α2β1

The amino acid composition of collagens from different animal species was determined and their binding capacities to integrin α2β1 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 to α2β1 was discussed. The results showed that there were significant differences among the binding capacities of collagens from different animal species to integrin α2β1 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 integrin α2β1 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 integrin α2β1, a mathematical model between the contents of hydroxyproline and arginine and collagen-integrin α2β1 binding was established by multivariate step-wise regression analysis, which had good predictive accuracy.