Spero L, Morlock B A
J Immunol. 1979 Apr;122(4):1285-9.
The strong cross-reactions demonstrated for staphylococcal enterotoxins B (SEB) and C1 (SEC1) by measurement of antigen-binding capacity were reflected in well defined polypeptides obtained by limited tryptic digestion from SEB and SEC1. Two antigenic determinants on each enterotoxin were capable of reacting with heterologous antibody, one on the first 57 amino acids and one on the last 150 residues of the polypeptide backbone. The larger, carboxyl terminal polypeptides bound efficiently to homologous antiserum but about two orders of magnitude less efficiently to heterologous antibody. The amino terminal peptides showed only weak homologous binding but nearly comparable heterologous binding. It is proposed that the determinant on the amino terminal polypeptides is largely responsible for the strong reciprocal binding of the intact enterotoxins and that their low antigen-binding capacity is due to a random or a structurally distorted conformation in solution.
通过测量抗原结合能力所显示的针对葡萄球菌肠毒素B（SEB）和C1（SEC1）的强烈交叉反应，在通过对SEB和SEC1进行有限胰蛋白酶消化而获得的明确多肽中得到体现。每种肠毒素上的两个抗原决定簇能够与异源抗体发生反应，一个位于多肽主链的前57个氨基酸上，另一个位于最后150个残基上。较大的羧基末端多肽能有效地与同源抗血清结合，但与异源抗体结合的效率约低两个数量级。氨基末端肽仅显示出较弱的同源结合，但异源结合几乎相当。有人提出，氨基末端多肽上的决定簇在很大程度上导致了完整肠毒素之间的强烈相互结合，并且它们较低的抗原结合能力是由于溶液中随机或结构扭曲的构象所致。
