Comparison of Certain Properties of Naturally Occurring Low Molecular Weight γM and the γM Monomer Derived by Reduction and Alkylation of 19 S γM

[摘要] A naturally occurring low molecular weight γM protein (γMN) was isolated from the serum of a patient with type I dysgammaglobulinemia by preparative electrophoresis and gel filtration. This protein was compared to the macroglobulin (γM19) isolated from the patient's serum and to the γM subunit (γMS) prepared by reduction and alkylation of γM19. The results indicate that γMN and γMS are similar in size and have the same antigenic determinants. These observations support the concept that the γMN is a naturally occurring subunit of γM19 and is very similar to γMS, γM19, γMN and γMS were also prepared from the patient's serum after tetanus immunization and were found to bind radiolabeled tetanus toxoid. Most, but not all, controls did not show nonspecific binding of tetanus toxoid. These results suggest but do not conclusively establish the capacity of these γM proteins to bind antigen specifically.

[学科分类] 生物科学（综合）