Frangione B, Prelli F, Mihaesco C, Franklin E C
Proc Natl Acad Sci U S A. 1971 Jul;68(7):1547-51. doi: 10.1073/pnas.68.7.1547.
Studies of the amino acid sequences around half-cystine residues in an immunoglobulin M have revealed an unexpectedly high number. At least 14 different sequences were found in the mu chain (V(HIII) subclass). Four of these were involved in interchain disulfide bridges and at least 10 in intrachain bridges. Five came from the kappa chain (kappa(III) subclass, Inv b). Several others, although having a high degree of homology, were not identical with those of either the mu or kappa chains. These results support the concept of an additional fragment in gammaM molecules, although its function and localization remain to be determined.
对免疫球蛋白M中半胱氨酸残基周围氨基酸序列的研究揭示了数量出乎意料的多。在μ链（V(HIII)亚类）中发现了至少14种不同的序列。其中4种参与链间二硫键桥，至少10种参与链内桥。5种来自κ链（κ(III)亚类，Inv b）。其他几种虽然具有高度同源性，但与μ链或κ链的序列并不相同。这些结果支持了γM分子中存在一个额外片段的概念，尽管其功能和定位仍有待确定。
