Isolation, preliminary characterization, and interferon antagonistic effect of a mammalian lectin-like substance.

Abstract

A tissue antagonist of interferon (TAI) was isolated from mouse costal cartilage which accelerates the decay of an established antiviral state. The effect is reminiscent of substances previously isolated from the basement membrane of human amnion. Since it was recently shown that phytohemagglutinin can mimic the biological effect of TAI, the possibility was explored that TAI could be an animal lectin-like material. TAI agglutinates mouse cells; this cell agglutination is inhibited by some sugars. Preliminary characterization indicates that the active molecule is a protein. After Sephadex G-100 gel filtration, TAI is found in a peak of 150,000 MW. When purified by isoelectric focusing, this peak shows maximal activities corresponding to an isoelectric point of pH 8.8. TAI binds to polysaccharide residues of the cell membrane which could be its primary site of action, comparable to phytohemagglutinin.