INTERACTION OF BIGLYCAN WITH TYPE-I COLLAGEN
INTERACTION OF BIGLYCAN WITH TYPE-I COLLAGEN
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DOI：
10.1074/jbc.270.6.2776
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发表时间：
1995-02-10
影响因子：
4.8
通讯作者：
KRESSE, H
中科院分区：
文献类型：
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作者：
SCHONHERR, E;WITSCHPREHM, P;KRESSE, H
已知小分子蛋白聚糖核心蛋白聚糖与I型胶原纤维相互作用，从而影响纤维形成的动力学以及相邻胶原纤维之间的距离。结构相关的蛋白聚糖双糖链蛋白聚糖被认为不与纤维状胶原蛋白结合。然而，当骨肉瘤细胞在重组的I型胶原纤维上培养时，核心蛋白聚糖和双糖链蛋白聚糖都被基质保留。电子显微镜水平的免疫金标记显示，这两种蛋白聚糖不仅在有骨肉瘤细胞的胶原网格中，而且在人皮肤中都沿胶原纤维分布。重组的I型胶原纤维在体外能够结合天然的和无N -聚糖的双糖链蛋白聚糖以及重组双糖链蛋白聚糖核心蛋白。从斯卡查德图（Scatchard plots）中获得了解离常数，糖基化双糖链蛋白聚糖的解离常数（8.7×10⁻⁸摩尔/升）高于糖基化核心蛋白聚糖（分别为7×10⁻¹⁰摩尔/升和3×10⁻⁹摩尔/升）。计算出两种蛋白聚糖的结合位点数量相似。与糖基化形式相比，重组双糖链蛋白聚糖和核心蛋白聚糖的解离常数较低。糖基化的以及重组的核心蛋白聚糖都与糖基化双糖链蛋白聚糖竞争胶原结合，这表明两种蛋白聚糖使用的是纤维上相同或相邻的结合位点。这些数据表明，由于其具有三价性，双糖链蛋白聚糖可能在细胞外基质的组装中具有特殊的组织功能。
The small proteoglycan decorin is known to interact with type I collagen fibrils, thereby influencing the kinetics of fibril formation and the distance between adjacent collagen fibrils. The structurally related proteoglycan biglycan has been proposed not to bind to fibrillar collagens. However, when osteosarcoma cells were cultured on reconstituted type I collagen fibrils, both decorin and biglycan were retained by the matrix. Immunogold labeling at the electron microscopic level showed that both proteoglycans were distributed along collagen fibrils not only in osteosarcoma cell-populated collagen lattices but also in human skin. Reconstituted type I collagen fibrils were able to bind in vitro native and N-glycan-free biglycan as well as recombinant biglycan core protein. From Scatchard plots dissociation, constants were obtained that were higher for glycanated biglycan (8.7 x 10(-8) mol/liter) than for glycanated decorin (7 x 10(-10) mol/liter and 3 x 10(-9) mol/liter, respectively). A similar number of binding sites for either proteoglycan was calculated. Recombinant biglycan and decorin were characterized by lower dissociation constants compared with the glycanated forms. Glycanated as well as recombinant decorin competed with glycanated biglycan for collagen binding, suggesting that identical or adjacent binding sites on the fibril are used by both proteoglycans. These data suggest that, because of its trivalency, biglycan could have a special organizing function on the assembly of the extracellular matrix.