Prelim inary Study on Fermentation Broth of Yeast Strain SH2 Enhancing Biological Activity of Interferon Alpha and Its Active Principle

The fermentation broth of yeast strain SH\-2?(FSH\-2) which could enhance the biological potency of human interferon alpha (huIFN ) was detected. Its enhancing ratio was 1.64～6.86 fold. A group of proteins was seperated and purified from the fermentation supernatant by chromatography on Sephadex G 75 and HPLC. Each protein showed the similar band on PAGE and SDS PAGE. Their molecular weights ranged from 52 to 72 kD. The proteins were stainded with periodic acid Schiff's agent. Lowry's method and sulfuric acid phenol method were respectively used to determine the contents of proteins and neutral sugars. The results showed the ratio of protein to sugar was 3∶1. These results indicated that the proteins were extracellular glycoproteins (YEGPs) secreted by yeast strain SH\-2. YEGPs could significantly enhance the biological potency of huIFN . It was veritied by the experiment of cytopathic effect inhibition in Wish cells. The enhancing ratios were 1.6～2.8 fold and 1.4～4.0 fold, respectively. The enhancing