The Presence in Normal Serum of Specific Antibody Against Bacteriophage T4 and Its Increase During the Earliest Stages of Immunization

[摘要] 1. 1. The sera of normal animals contain minute amounts of a specific antibody A which can act on T4 bacteriophage. The relative concentrations of antibody A in different sera can be precisely measured. The concentration of antibody A in the blood of an animal may be increased by a factor 100 within 4 days after stimulating the animals with a single injection of T4 antigen. It is not increased on immunization with unrelated antigens. On immunization with T4 phage the production of antibody A precedes the production of T4-inactivating antibodies in time, and thus provides a means of investigating the early stages of the response of an animal to an antigen stimulus.2. 2. Antibody A reveals its presence by permanently activating T4 particles of certain strains which are reversibly activated by tryptophane and other cofactors. The kinetics of activation suggest the following points concerning the activation mechanism. Structures at each of about five sites on a T4 particle oscillate independently between two states. A particle can become active when all sites are simultaneously in the positive state. Antibody A, tryptophane, and indole act only on individual positive sites, retarding or precipitating their relapse into the negative state.

[学科分类] 生物科学（综合）