Precipitin Reactions of Various Ovalbumins

Chicken, pearl guinea fowl and amherst pheasant ovalbumins∗ were crystallized 4 times by the method previously described for chicken ovalbumin by Cole. 1 These crystallized proteins, together with a purified chicken-blood albumin, were injected into rabbits and the antiserums produced were tested with the various antigens by the precipitin-reaction. Chicken-blood albumin was included in these experiments because we had previously shown that it is immunologically identical with the conalbumin in chicken egg-white, 2 so that an antiserum against this protein may be used to detect the presence or absence of conalbumin in supposedly pure preparations of the other proteins in egg-white. The results obtained are summarized in Tables I and II. The figures represent the highest dilution of the antigen which, when layered over some of the undiluted antiserum, still gave a visible precipitate at the interface between antigen and antiserum in one hour at room-temperature.

As indicated in Table I, the antiserum against chicken ovalbumin is specific, reacting only with the homologous antigen. On the other hand, the antiserums against the pearl guinea fowl and amherst pheasant ovalbumins react not only with the homologous antigens, but also with the other 2 crystallized ovalbumins. None of these crystallized proteins react with conalbumin-antiserum, while their mother-liquors, which contain some of the crystallizable as well as the non-crystallizable albumin in the egg-white, give strong reactions with this antiserum. These reactions of the mother-liquors with an antiserum against chicken conalbumin indicate that the conal-bumins in these various egg-whites are either similar or identical, and, judging from the results of our earlier work on chicken-blood albumin and conalbumin, that the blood-albumins of these fowl are also similar or identical. The complete absence of cross-reactions between the crystallized ovalbumins and the conalbumin indicates that each of the ovalbumins used in these experiments is a pure substance, entirely free from contamination with the conalbumin which appears to be a common constituent of all these egg-whites, We are thus led to the conclusion that whereas chicken ovalbumin gives rise to a single, specific antibody, the injection of pearl guinea fowl or amherst pheasant ovalbumin leads either to the formation of several distinct antibodies, or else a single antibody capable of reacting with the various ovalbumins.