Hearst Laboratory of Pathology and Bacteriology, and the Rudolph Spreckels Physiological Laboratory of the University of California, Berkeley.
J Exp Med. 1912 Oct 1;16(4):470-8. doi: 10.1084/jem.16.4.470.
We draw the following conclusions from our experiments on the antigenic properties of chemically pure casein and some of its split products. Casein and paranuclein have distinct antigenic properties, particularly as shown by their ability to sensitize guinea pigs for subsequent anaphylactic intoxication by each other or by milk. This sensitizing ability and a corresponding ability to intoxicate are indistinguishably equivalent, under the conditions employed. On immunizing rabbits by repeated injections of paranuclein or of casein, and subsequently testing their sera for precipitins and fixation antibodies, it was found that casein apparently produces them much more readily, giving an antiserum that reacted (fixation) in very high dilution with casein (0.000,000,1 of a 1 per cent. solution), but much less strongly with paranuclein. Only one of two antiparanuclein sera showed the presence of antibodies to paranuclein by the delicate fixation reaction, and that in relatively small amounts. The two antibodies to casein and to paranuclein are, in the case of casein quantitatively, and in the case of paranuclein absolutely specific. A solution of the products of complete peptic digestion of casein fails to sensitize to paranuclein and gives no fixation reaction with an anticasein or antiparanuclein serum. It intoxicates animals sensitized to paranuclein but no more markedly than it does normal animals. It also fails to show specific intoxication in an animal that has been sensitized by the same substance. The amino acids, glutamic acid, and leucin, the principal components of their kind in casein, and in the same proportion therein present, likewise failed to show antigenic properties. They do not sensitize animals to milk intoxication or to intoxication by themselves, and likewise failed to produce precipitins in rabbits in a preliminary experiment. These experiments are regarded as a fairly systematic analysis of the antigenic properties of split products of a single protein. They are analogous to, though less complete than the work of Wells (6) on egg-white. They seem to present the additional advantage of dealing with what is probably the only protein certainly known chemically, and in its purest form. They serve, moreover, as an introduction to the following study of the antigenic properties of a combined protein.
我们从对化学纯酪蛋白及其某些分解产物的抗原特性的实验中得出以下结论。酪蛋白和副核蛋白具有明显的抗原特性，特别是它们能够使豚鼠致敏，随后用彼此或用牛奶引起过敏中毒。在使用的条件下，这种致敏能力和相应的中毒能力是不可区分的等效的。通过反复注射副核蛋白或酪蛋白对兔子进行免疫接种，然后测试其血清中的沉淀素和固定抗体，发现酪蛋白显然更容易产生它们，产生的抗血清与酪蛋白（1%溶液的 0.000,000,1）反应（固定）的稀释度非常高，但与副核蛋白的反应强度较低。只有两种抗副核蛋白血清中的一种通过精细的固定反应显示出存在针对副核蛋白的抗体，而且数量相对较少。两种针对酪蛋白和副核蛋白的抗体在酪蛋白的情况下是定量的，而在副核蛋白的情况下是绝对特异性的。完全胃蛋白酶消化酪蛋白产物的溶液不能使副核蛋白致敏，并且与抗酪蛋白或抗副核蛋白血清没有固定反应。它使对副核蛋白致敏的动物中毒，但不如正常动物更明显。它也未能在同一物质致敏的动物中显示出特异性中毒。氨基酸谷氨酸和亮氨酸是酪蛋白及其主要成分的主要成分，在酪蛋白中也以相同的比例存在，同样没有表现出抗原特性。它们不能使动物对牛奶中毒或自身中毒致敏，并且在初步实验中也不能在兔子中产生沉淀素。这些实验被认为是对单个蛋白质的分解产物的抗原特性进行的相当系统的分析。它们与威尔斯（6）关于蛋清的工作类似，尽管不那么完整。它们似乎具有处理可能是唯一一种在化学上肯定已知的蛋白质及其最纯形式的额外优势。此外，它们还为以下对结合蛋白的抗原特性的研究提供了介绍。
