Fujisawa R, Mizuno M, Nodasaka Y, Kuboki Y
Department of Biochemistry, School of Dentistry, Hokkaido University, Sapporo, Japan.
Matrix Biol. 1997 Apr;16(1):21-8. doi: 10.1016/s0945-053x(97)90113-x.
We investigated activity of bone sialoprotein (BSP) to mediate attachment of cells to hydroxyapatite using a model peptide, Glu7-Pro-Arg-Gly-Asp-Thr, which contains a putative hydroxyapatite-binding site (poly-Glu) and a cell-attachment site. The peptide has affinity to hydroxyapatite with a dissociation constant of 13.5 microM. The peptide affected in vitro mineralization in a gel system, indicating interaction between this peptide and calcium phosphate. The osteoblastic cell line MC3T3-E1 was incubated with hydroxyapatite powder coated with the peptide or proteins. Attachment of the cells was observed on the powder coated with BSP, but not on the powder coated with serum albumin. The cells were attached to the powder coated with the peptide. The cells were flattened on the powder, and pseudopods developed. The attachment of the cells was inhibited by an excessive amount of Gly-Arg-Gly-Asp-Ser peptide. In conclusion, BSP mediated attachment of osteoblastic cells to hydroxyapatite, and this activity could be accomplished only by the poly-Glu sequence and the Arg-Gly-Asp sequence.
我们使用一种模型肽Glu7-Pro-Arg-Gly-Asp-Thr研究了骨唾液蛋白（BSP）介导细胞与羟基磷灰石附着的活性，该肽包含一个假定的羟基磷灰石结合位点（聚谷氨酸）和一个细胞附着位点。该肽对羟基磷灰石具有亲和力，解离常数为13.5微摩尔。该肽在凝胶系统中影响体外矿化，表明该肽与磷酸钙之间存在相互作用。将成骨细胞系MC3T3-E1与涂有该肽或蛋白质的羟基磷灰石粉末一起孵育。在涂有BSP的粉末上观察到细胞附着，但在涂有血清白蛋白的粉末上未观察到。细胞附着在涂有该肽的粉末上。细胞在粉末上扁平，形成伪足。过量的甘氨酸-精氨酸-甘氨酸-天冬氨酸-丝氨酸肽抑制细胞的附着。总之，BSP介导成骨细胞与羟基磷灰石的附着，且这种活性仅由聚谷氨酸序列和精氨酸-甘氨酸-天冬氨酸序列完成。
