Dahr W, Metaxas-Bühler M, Metaxas M N, Gallasch E
J Immunogenet. 1981 Apr;8(2):79-87. doi: 10.1111/j.1744-313x.1981.tb00745.x.
The major erythrocyte membrane (MN) sialoglycoprotein in Mg red cells was found to exhibit a slightly decreased sodium-dodecyl-sulphate polyacrylamide gel electrophoretic molecular weight and periodic and/Schiff staining intensity. Mg antigen activity was shown to be associated with this molecule. As judged from chemical modification experiments, no carbohydrate but the glycoprotein's N-terminal amino acid is involved in the Mg receptor site. The endgroup of the glycoprotein was found to leucine and studies involving Staphylococcus aureus V8 protease suggest that a glutamic acid is located at the fifth position of its peptide chain. This indicates that the Mgs gene complex evolved from a mutation of an Ns allele. An amino acido substitution or deletion at the second, third and/or fourth position(s), preventing the glycosylation of all or some of these amino acids, provides an explanation for the properties of Mg erythrocytes.
在低镁红细胞中发现，主要的红细胞膜（MN）唾液酸糖蛋白在十二烷基硫酸钠聚丙烯酰胺凝胶电泳中的分子量略有降低，且过碘酸希夫染色强度呈周期性变化。已证明Mg抗原活性与该分子相关。从化学修饰实验判断，除了糖蛋白的N端氨基酸外，没有碳水化合物参与Mg受体位点。发现糖蛋白的末端基团是亮氨酸，涉及金黄色葡萄球菌V8蛋白酶的研究表明，其肽链的第五位存在谷氨酸。这表明Mgs基因复合体是由Ns等位基因的突变进化而来。在第二、第三和/或第四位的氨基酸取代或缺失，阻止了所有或部分这些氨基酸的糖基化，这为Mg红细胞的特性提供了解释。
