A New Serum Factor in Normal Rabbits

[摘要] Homoreactant in rabbits has been shown to be passively transmitted from mother to fetus, thus fulfilling another criterion of its immunoglobulin nature. Newly synthesized HR began to appear in the newborn rabbit sera immediately after the disappearance of maternal HR, i.e., 4 to 5 weeks after parturition.Early HR characterized as a γM-globulin by 2-ME sensitivity and DEAE-cellulose chromatography was actively synthesized by the newborn rabbit only between the ages of 4 and 10 weeks. This was followed by the continued synthesis of a 2-ME resistant γG-globulin HR. This constitutes the first observation of an apparent 19 S to 7 S transition in the synthesis of a natural antibody.Both the 2-ME susceptible and 2-ME resistant forms of HR were directed to determinants which are otherwise buried in the intact γG-globulin molecule and exposed by digestion with papain.

[学科分类] 生物科学（综合）