Biswas C
Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts.
J Cell Physiol. 1988 Jul;136(1):147-53. doi: 10.1002/jcp.1041360119.
We have reported previously that the production of a tumor cell factor that stimulates synthesis of fibroblast collagenase is influenced by a fibroblast-deposited matrix component, possibly heparan sulfate-proteoglycan. In this study, binding sites for heparin and heparan sulfate on mouse B-16 melanoma cells have been demonstrated. Binding of 3H-heparin and 35S-heparan sulfate has been shown to occur to whole cells, isolated membranes, and to a component(s) of detergent extracts of the membranes. Scatchard analysis of binding of 3H-heparin yielded a Kd of 2-5 x 10(-8) M and a Bmax of 0.5 x 10(7) heparin molecules bound per cell. Binding of 35S-heparan sulfate was of at least an order of magnitude lower affinity than heparin, but the Bmax was similar to that for heparin. Competition studies showed that 35S-heparan sulfate binding was inhibited totally by heparin and heparan sulfate and partially by dermatan sulfate, but no inhibition was obtained with hyaluronate or chondroitin sulfate. Binding of 3H-heparin was inhibited totally by heparin but to different extents by preparations of heparan sulfate from different tissue sources. The heparin/heparan sulfate binding activity is a protein(s) because it is destroyed by treatment with trypsin. Binding of 3H-heparin to transblots of the detergent extract of the B-16 cell membranes indicated that at least part of the binding activity is a 14,000-dalton protein.
我们先前曾报道，一种刺激成纤维细胞胶原酶合成的肿瘤细胞因子的产生，受成纤维细胞沉积的基质成分影响，可能是硫酸乙酰肝素蛋白聚糖。在本研究中，已证实小鼠B - 16黑色素瘤细胞上存在肝素和硫酸乙酰肝素的结合位点。已表明3H - 肝素和35S - 硫酸乙酰肝素可与完整细胞、分离的细胞膜以及膜去污剂提取物的一种或多种成分发生结合。对3H - 肝素结合进行Scatchard分析得出，解离常数（Kd）为2 - 5×10（-8）M，每个细胞结合的最大结合量（Bmax）为0.5×10（7）个肝素分子。35S - 硫酸乙酰肝素的结合亲和力比肝素至少低一个数量级，但Bmax与肝素相似。竞争研究表明，35S - 硫酸乙酰肝素的结合被肝素和硫酸乙酰肝素完全抑制，被硫酸皮肤素部分抑制，但透明质酸或硫酸软骨素无抑制作用。3H - 肝素的结合被肝素完全抑制，但被来自不同组织来源的硫酸乙酰肝素制剂不同程度地抑制。肝素/硫酸乙酰肝素结合活性是一种蛋白质，因为用胰蛋白酶处理会使其被破坏。3H - 肝素与B - 16细胞膜去污剂提取物的转印膜结合表明，至少部分结合活性是一种14,000道尔顿的蛋白质。
