Purification and Characterization of Mouse L Cell Interferon

Abstract

Interferon was produced in high yields in mouse L cell cultures infected with Newcastle disease virus, with a specific activity of the order of 106 units per mg protein. It was partially purified by zinc acetate precipitation, carboxymethyl Sephadex chromatography, Sephadex gel filtration and pressure dialysis. On electrophoresis in polyacrylamide gel, it consisted of a fast‐moving sharp component and a slow, broadly distributed component(s). The highest specific activity of the former component so far obtained was 8 × 107 units per mg protein, numerically the highest value ever reported for interferon. It was considered likely, however, that the protein components in the purified samples, revealed by staining of the electrophoresis gel, still represented mostly impurities. Gel filtration experiment indicated some heterogeneity of interferon in molecular weight but the major component was estimated to be 30 000 in molecular weight. Interferon activity could be maintained without added preservatives for prolonged periods, provided that the protein concentration of the sample itself was high. One interferon unit as defined in this paper was found to correspond to 0.3 international unit.

Enhancing Effect of Interferon Pretreatment on Interferon Production

“…The homologous IF preparations were as follows; 1) IFs induced with poly I.poly C, NDV or ET which possessed different sensitivities to heat and pH [5], 2) early-and late-appearing IFs which were prepared at different times after induction with poly I-poly C, 3) IFs induced with high and low concentrations of poly I.poly C and then diluted to equal concentrations, 4) partially purified IFs induced with NDV [4]. Pretreatment of L cells with all these mouse IFs showed similar enhancing effects upon IF production.…”

Sequential Antibody Affinity Chromatography of Human Leukocyte Interferon

“…The purification and characterization of human leukoq'te interferon has until recently (1,2) been attempted only by traditional physicochemical methods, such as gel HItration (5), ion-exchange chromatography (5), and electrophoresis (8). When these methods are combined, reasonably good purification is obtained (5, 8,9), but the final yield is often very poor. Different lecithins have been used, but so far without great success as far as the leitkocyte interferon is concerned (Sulkowsky, personal communication).…”

Production and Purification of Human MG63 Cell Interferon

“…Clarified culture fluid was used for the experiments. Sendai virus (28), originally from Dr. K. Cantell and kindly provided by Dr. T. Kishida, and NDV, Miyadera strain (17), were grown in fertilized chicken eggs, and purified by high speed centrifugation.…”