REACTIVE LYSIS: THE COMPLEMENT-MEDIATED LYSIS OF UNSENSITIZED CELLS

TLDR

The physicochemical characteristics of I are compatible with published data on C7. This paper describes the characteristics of the indicator factor (I) involved in reactive hemolysis and identifies it as the seventh complement component. The authors performed depletion experiments with anti‑I antiserum or activated euglobulin, showing that I is a late‑acting complement component required for cell lysis after the EAC142 stage, and they developed a convenient quantitation method for testing C7. I is a beta globulin of about 140,000 Da with a 5.7S sediment coefficient, and component analysis of purified fractions identified it as C7.

Abstract

This paper describes the characteristics of the indicator factor (I) which takes part in reactive hemolysis and its identification as the seventh component of complement. I was shown to be a beta globulin with a sediment coefficient of 5.7S and a molecular weight of about 140,000. Experiments on the depletion of I activity with anti-I antiserum or with activated R euglobulin showed that I was a late acting complement component necessary for the lysis of cells after the EAC142 stage. Complement component analysis of purified I fractions excluded all known components except C7. The physicochemical characteristics of I are compatible with published data on C7. The method of quantitation described represents a convenient method of testing for C7.