%0 Journal Article %A Stewart, W. E. %A De Somer, P. %A Edy, V. G. %A Paucker, K. %A Berg, K. %A Ogburn, C. A. %T Distinct Molecular Species of Human Interferons: requirements for Stabilization and Reactivation of Human Leukocyte and Fibroblast Interferons %D 1975 %J Journal of General Virology, %V 26 %N 3 %P 327-331 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-26-3-327 %I Microbiology Society, %X SUMMARY Human fibroblast interferon preparations were completely stabilized to 100 °C by sodium dodecyl sulphate (SDS) in the presence of mercaptoethanol, but only a minor fraction of their activities were stabilized by SDS without mercaptoethanol. On the contrary, human leukocyte interferon preparations were completely stabilized to 100 °C by SDS in the absence of mercaptoethanol, but only a minor fraction of their activities were stabilized by SDS in the presence of mercaptoethanol. Furthermore, human fibroblast interferon preparations whose activities had been destroyed by boiling at 100 °C were completely reactivated by SDS under reducing conditions, but only a minor part of their activities were restored by SDS in the absence of reduction. On the contrary, human leukocyte interferon preparations whose activities had been destroyed by boiling at 100 °C were completely reactivated by SDS in the absence of reduction, but only a minor part of their activities were restored by SDS under reducing conditions. These data suggest that there are distinct molecular species of human interferons. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-26-3-327