Hydrophobicity of Neuraminidase-Treated Rabbit Interferon

Abstract

Summary

Poly(rI):poly(rC)-superin-duced rabbit interferon can be separated by elution into two populations in a bovine serum albumin-bound Sepharose 4B column by phosphate-buffered saline (E_o) and by an eluent containing a polar reducing agent (E₂). Approximately 88% of interferon activity is eluted with E_o, along with all detectable protein, while there is about 12% of interferon activity bound to the column which can only be eluted with E₂. After interferon is treated with neuraminidase, it is found that the majority of the activity (80%) is bound to the column and can only be eluted with E₂. Only 20% of the activity is found in the E_o fractions, which also contain all measurable protein. The sialic acid residue of interferon may therefore be related to the hyperphobicity of the molecules.

The author wishes to thank Patricia Faus and Janet Hinman for technical assistance, Dr. S. Papaioarmou for proteolytic enzyme assays, Searle Bioanalytical Laboratory for protein measurements, and Jean Flink for the preparation of the manuscript.