The Effect of Ninhydrin Upon Horse-Serum-Protein and Antibodies

[摘要] 1. 1. Ninhydrin combines with some of the amino groups of serum-proteins, to produce altered proteins having new physical and chemical properties.2. 2. Such ninhydrinized proteins are not coagulated by heat at reactions higher than pH 5.5.3. 3. In salt-free solution, their isoelectric point is shifted toward the acid side. In the presence of salt they are insoluble at reactions lower than pH 5.0.4. 4. They are more readily salted out by neutral salts than are the unaltered proteins.5. 5. The blue pigment is readily formed from the albumin and pseudoglobulin of the serum, but to a lesser extent or not at all by the water-insoluble globulins.6. 6. Thyphoid H-agglutinins are not injured by ninhydrin; they are considerably concentrated in the acid- and the salt-precipitates of ninhydrinized horse-serum. They are among the first of the proteins of immune horse-serum to be altered.7. 7. Typhoid O-agglutinins and type I pneumococcal antibodies are partially destroyed by ninhydrin.8. 8. Certain similarities as well as differences between the action of ninhydrin and formaldehyde upon serum-proteins and antibodies have been indicated and discussed.

[学科分类] 生物科学（综合）