抗葡萄球菌血清α球蛋白分析

Analysis of an antistaphylococcal serum alpha globulin.

作者信息

Lentino J R, Yotis W W

出版信息

Zentralbl Bakteriol Orig A. 1977 Sep;239(1):31-41.

Abstract

Previous studies in this laboratory have shown that normal human serum contains an alpha globulin possessing lethal and antirespiratory action for staphylococci. In this study further description of the antistaphylococcal macromolecule is presented. The antistaphylococcal protein was shown to be homogeneous by both isoelectric focusing in sucrose density gradients and sodium dodecyl sulfate electrophoresis. An analysis of the chemical composition of the antistaphylococcal serum protein indicated the alpha globulin to be a glycoprotein composed of 22.5% carbohydrate and 77.2% protein as determined by amino acid analysis. The total carbohydrates included 11.08% protein-bound hexoses. 0.86% hexosamines, 4.3% sialic acid and 6.3% fucose. The mean isoelectric point, determined by isoelectric focusing in the range pH 3-6, was 4.73. Molecular weight studies on Sephadex G-200 dextran gel columns calibrated with proteins and glycoproteins indicated the molecular weight of the antistaphylococcal macromolecule to be 55,000-74,000 daltons respectively. SDS-gel electrophoresis indicated the molecular weight of antistaphylococcal serum protein was 62,000. Thus the antistaphylococcal alpha globulin does not appear to be related to other known serum bactericidins.

摘要

本实验室先前的研究表明，正常人血清中含有一种对葡萄球菌具有致死和抗呼吸作用的α球蛋白。在本研究中，对这种抗葡萄球菌大分子进行了进一步描述。通过在蔗糖密度梯度中进行等电聚焦和十二烷基硫酸钠电泳，证明抗葡萄球菌蛋白是均一的。对抗葡萄球菌血清蛋白的化学成分分析表明，通过氨基酸分析确定，α球蛋白是一种糖蛋白，由22.5%的碳水化合物和77.2%的蛋白质组成。总碳水化合物包括11.08%的蛋白结合己糖、0.86%的己糖胺、4.3%的唾液酸和6.3%的岩藻糖。通过在pH 3 - 6范围内进行等电聚焦测定的平均等电点为4.73。在用蛋白质和糖蛋白校准的Sephadex G - 200葡聚糖凝胶柱上进行的分子量研究表明，抗葡萄球菌大分子的分子量分别为55,000 - 74,000道尔顿。SDS - 凝胶电泳表明抗葡萄球菌血清蛋白的分子量为62,000。因此，抗葡萄球菌α球蛋白似乎与其他已知的血清杀菌素无关。