[Immunochemical characteristics of human blood proteins, exhibiting anti-influenza gamma-inhibitor activity].

The molecular composition of gamma-inhibitors in human serum was found to be heterogenous. In gel filtration of serum gamma-inhibitors were detected in macroglobulin 19S and low molecular 4S fractions. Heating at 100 degrees C for 10 min resulted in a considerable (32--128-fold) increase of the activity of 19S and 4S gamma-inhibitors. A mixture of specific antibody and gamma-inhibitors could be isolated from human serum by means of immunosorbent. The eluate from the immunosorbent was separated into two fractions in gel filtration through Sephadex G-200 column. According to the results of HI tests, both fractions showed the activities of both antibody and gamma-inhibitors. Proteins of the eluate and its fractions were identified by means of disc electrophoresis in polyacrylamide gel and immunodiffusion analysis. The function of gamma-inhibitors in human sera was found to be performed by alpha2-macroglobulins and transferrin. Antibody for influenza A2/Singapore/1/57 virus belong to IgG and IgA classes.