Kawakami H, Terayama H
Biochim Biophys Acta. 1980 Jun 20;599(1):301-14. doi: 10.1016/0005-2736(80)90076-0.
Proteoglycan (heparan sulfate-protein conjugate) was solubilized with 8 M urea from rat liver plasma membranes after enzymic (RNAase, neuraminidase) treatments and extensively purified by chromatography and gel filtration. The final products gave an average ratio of hexuronate to protein (weight) of approx. 1.5, contained hexosamine equimolar to hexuronate and were sensitive to beta-elimination (the molecular weight being reduced from 20 . 10(4) to 3 . 10(4) (gel filtration)). The proteoglycan fraction, when added to trypsinized and untrypsinized ascites hepatoma (AH-130F(N)) cells, inhibited the concanavalin A-mediated agglutination of the cells. However, the alkali-treated proteoglycan (beta-elimination) or acid mucopolysaccharide fraction prepared from liver plasma membranes by papain digestion were less effective, and a reference preparation of heparan sulfate was almost ineffective. It was confirmed that significant amounts of proteoglycan labelled with 35SO4(2-) were firmly bound to or taken up by the trypsinized ascites hepatoma cells. These results together with the sensitization of lectin-mediated agglutination by mild protease treatment of cells suggest that cell surface proteoglycans may act as a negative modulator in the lectin-mediated agglutination of cells.
用8M尿素从经酶（RNA酶、神经氨酸酶）处理的大鼠肝细胞膜中溶解蛋白聚糖（硫酸乙酰肝素-蛋白质共轭物），并通过色谱法和凝胶过滤进行广泛纯化。最终产物的己糖醛酸与蛋白质（重量）的平均比值约为1.5，含有与己糖醛酸等摩尔的己糖胺，并且对β-消除敏感（分子量从20×10⁴降至3×10⁴（凝胶过滤））。当将蛋白聚糖部分添加到经胰蛋白酶处理和未经胰蛋白酶处理的腹水肝癌（AH-130F(N)）细胞中时，会抑制伴刀豆球蛋白A介导的细胞凝集。然而，经碱处理的蛋白聚糖（β-消除）或通过木瓜蛋白酶消化从肝细胞膜制备的酸性粘多糖部分效果较差，硫酸乙酰肝素的参比制剂几乎无效。已证实，大量用³⁵SO₄²⁻标记的蛋白聚糖与经胰蛋白酶处理的腹水肝癌细胞牢固结合或被其摄取。这些结果与通过对细胞进行温和蛋白酶处理使凝集素介导的凝集敏化的现象一起表明，细胞表面蛋白聚糖可能在凝集素介导的细胞凝集过程中充当负调节剂。
