Buxman M M, Wuepper K D
Biochim Biophys Acta. 1976 Dec 8;452(2):356-69. doi: 10.1016/0005-2744(76)90185-6.
A crosslinking enzyme, epidermal transglutaminase, was isolated from soluble proteins of glabrous cow snout epidermis. This enzyme stabilized fibrin clots rendering them insoluble in 2% acetic acid. It also catalyzed the incorporation of the fluorescent amine, dansyl cadaverine, into casein. Epidermal transglutaminase was purified by chromatography upon DEAE-Sephadex A-50, zone electrophoresis in Pevikon, and Sephadex G-200 gel permeation chromatography. The highly purified substance, which had a specific activity of 3267 amine-incorporating units/mg per h and a molecular weight of 55000, behaved as a single molecular species in the analytical ultracentrifuge. It had a sedimentation coefficient of 4.4 S and migrated as a gamma-globulin at pH 8.6; it displayed anomalous migration in polyacrylamide gels containing sodium dodecyl sulfate. The enzyme was dependent upon free calcium ions and a reduced sulfhydryl group for activity. The apparent Km for dansyl cadaverine was 1.2 - 10(-4) at pH 7.5. Monospecific antiserum to bovine epidermal transglutaminase precipitated with the enzyme in agar. The antiserum prevented fibrin crosslinking but enhanced incorporation of dansyl cadaverine into casein by the enzyme. The epidermal enzyme differed biochemically and immunochemically from bovine plasma transglutaminase (Factor XIII).
一种交联酶，即表皮转谷氨酰胺酶，是从无毛牛鼻表皮的可溶性蛋白质中分离出来的。这种酶能使纤维蛋白凝块稳定，使其在2%的醋酸中不溶解。它还催化荧光胺丹磺酰尸胺掺入酪蛋白。表皮转谷氨酰胺酶通过DEAE-葡聚糖A-50柱层析、在聚乙烯醇凝胶中的区带电泳以及葡聚糖G-200凝胶渗透层析进行纯化。高度纯化的物质，其比活性为每小时每毫克3267个胺掺入单位，分子量为55000，在分析超速离心机中表现为单一分子种类。它的沉降系数为4.4 S，在pH 8.6时作为γ-球蛋白迁移；在含有十二烷基硫酸钠的聚丙烯酰胺凝胶中显示出异常迁移。该酶的活性依赖于游离钙离子和一个还原的巯基。在pH 7.5时，丹磺酰尸胺的表观Km为1.2×10⁻⁴。抗牛表皮转谷氨酰胺酶的单特异性抗血清在琼脂中与该酶沉淀。该抗血清可阻止纤维蛋白交联，但能增强该酶将丹磺酰尸胺掺入酪蛋白的能力。表皮酶在生化和免疫化学方面与牛血浆转谷氨酰胺酶（因子XIII）不同。
