Horner A A
Department of Physiology, University of Toronto, Ontario, Canada.
Biochem J. 1987 Jun 15;244(3):693-8. doi: 10.1042/bj2440693.
Subfractions of 35S-labelled rat skin heparin proteoglycans with various degrees of high affinity for antithrombin were obtained by gradient elution from a column of antithrombin-agarose. Heparin chains released from the proteoglycan preparations by beta-elimination with alkali were re-fractionated on the same column. Proportions of chains with high affinity for antithrombin (HA-chains) ranged from 17% to 76%. These separations also revealed three overlapping subfractions of HA-chains. Their proportions varied in a manner consistent with a stepwise increase in the degree of affinity of HA-chains for antithrombin, this presumably being due to the biosynthesis of increasing numbers of antithrombin-binding sites per chain. The anticoagulant activity, with respect to thrombin neutralization, ranged from 32 units/mg to 287 units/mg. It is suggested that HA-chains may have from one to five or six antithrombin-binding sites. Thus the asymmetric distribution of these sites in rat skin heparin proteoglycans is much more marked than was realized from the earlier work of Horner & Young [(1982) J. Biol. Chem. 257, 8749-8754].
通过从抗凝血酶 - 琼脂糖柱上进行梯度洗脱，获得了对抗凝血酶具有不同程度高亲和力的35S标记大鼠皮肤肝素蛋白聚糖亚组分。通过用碱进行β-消除从蛋白聚糖制剂中释放的肝素链在同一柱上重新分级分离。对抗凝血酶具有高亲和力的链（HA链）的比例范围为17％至76％。这些分离还揭示了HA链的三个重叠亚组分。它们的比例变化方式与HA链对抗凝血酶亲和力程度的逐步增加一致，这可能是由于每条链上抗凝血酶结合位点数量的增加所致。相对于凝血酶中和的抗凝活性范围为32单位/毫克至287单位/毫克。有人提出HA链可能具有一至五个或六个抗凝血酶结合位点。因此，这些位点在大鼠皮肤肝素蛋白聚糖中的不对称分布比霍纳和扬早期的研究[(1982) J. Biol. Chem. 257, 8749 - 8754]所认识到的要明显得多。
