Baskova I P, Cherkesova D U
Biokhimiia. 1980 Feb;45(2):267-72.
During isolation and purification involving fractionation by acetone, ethanol and affinity chromatography on trypsin-Sepharose and isoelectrofocusing hirudin from whole leeches behaves as the inhibitor isolated from leech heads and "pseudohirudin" from leech bodies. The antithrombin activity of hirudin fractions obtained by isoelectrofocusing is about three times less than that of the corresponding hirudin fractions from the heads. The "pseudohirudin" fractions are practically devoid of the antithrombin activity. In hirudin prepared from whole leeches isoleucine and valine were identified as N-terminal amino acids. The antithrombin activity and N-terminal amino acids suggest that hirudin from whole leeches contains admixtures of inactive "pseudohirudin". Hirudin from leech heads purified by complexing with thrombin possesses the activity of 15600 ATNIH units per pg of protein and has isoleucine as an N-terminal amino acid.
在通过丙酮、乙醇分级分离以及在胰蛋白酶-琼脂糖凝胶上进行亲和层析和等电聚焦从整条水蛭中分离纯化水蛭素的过程中，其表现与从水蛭头部分离得到的抑制剂以及从水蛭身体中得到的“假水蛭素”相似。通过等电聚焦得到的水蛭素级分的抗凝血酶活性比来自头部的相应水蛭素级分低约三倍。“假水蛭素”级分实际上没有抗凝血酶活性。从整条水蛭制备的水蛭素中，异亮氨酸和缬氨酸被鉴定为N端氨基酸。抗凝血酶活性和N端氨基酸表明，来自整条水蛭的水蛭素含有无活性的“假水蛭素”混合物。通过与凝血酶络合纯化的水蛭头部的水蛭素每微克蛋白质具有15600抗凝血酶单位（AT - NIH）的活性，并且以异亮氨酸作为N端氨基酸。
