. Analysis of development. Embryology; Embryology. may depend upon relatively small determi- nant groups rather than on the whole struc- ture of the molecule, and that the molecule may contain more than one kind of determi- nant group. Unfortvmately very little is known about the size, number and kind of determinant groups of natural proteins. Ex- periments by Landsteiner ('42) with hydrol- ysates of silk protein have shown that pep- tides of molecular weight of 600 to 1000 can specifically inhibit the precipitation of the intact protein by its antiserum. For the pres- ent we can only conclude
. Analysis of development. Embryology; Embryology. may depend upon relatively small determi- nant groups rather than on the whole struc- ture of the molecule, and that the molecule may contain more than one kind of determi- nant group. Unfortvmately very little is known about the size, number and kind of determinant groups of natural proteins. Ex- periments by Landsteiner ('42) with hydrol- ysates of silk protein have shown that pep- tides of molecular weight of 600 to 1000 can specifically inhibit the precipitation of the intact protein by its antiserum. For the pres- ent we can only conclude by analogy with the results of experiments on the coupled proteins that natural proteins may induce the formation of more than one kind of anti- body. Some of the antibody molecviles wovdd be specific for one determinant group, some. Fig. 207. Diagram illustrating the three kinds of antibody molecules that may be produced in response to immunization with an antigen containing two different kinds of determinant groups. clear, then, that a single kind of protein can give rise to more than one kind of antibody. This is illustrated further when two different haptens (A and B, see Fig. 207) are coupled with a protein. Thus Haurowitz and Schwerin ('43) obtained distinct anti-A and anti-B antibodies upon injection of such an antigen. They did not find a third possible type, anti-AB. However, Dodd ('52) presents strong evidence for this type of antibody in grovip O humans immunized with mixed A and B antigens, as well as for its occurrence in normal human group 0 sera (see also Bird, '53). A less satisfactory interpretation is that some anti-A and anti-B antibodies in group O sera are more cross-reacting than are others. The work with haptens serves to emphasize that in natural proteins antigenic specificity * A complex hapten, formed by coupling more than one molecule with a simple substance such as resorcinol, can form a precipitate with the anti- bodies produced by injection of the
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Keywords: ., bookcentury1900, bookpublisherphiladelphi, booksubjectembryology
