BIOCHEMICAL-PROPERTIES OF AN ENHANCING FACTOR OF AN ENTOMOPOXVIRUS

Spheroids of a Pseudaletia separata entomopoxvirus contained a factor which enhanced the infection of a nuclear polyhedrosis virus in larvae of the armyworm, P. separata. The enhancing factor (EF) was purified from the spheroid solution by two-step procedures consisting of gel filtration on a sephacryl column and adsorption chromatography on a hydroxyapatite column. The final EF preparation was about 20-fold greater in enhancing activity, based on ID50, than the original spheroid solution. SDS-polyacrylamide gel electrophoresis indicated that the EF was a homogeneous glycoprotein of 38 kDa. It could be stored frozen or lyophilized. Although the EF differed in molecular weight from a synergistic factor of a Pseudalelia unipuncla granulosis virus, they were considerably similar in amino acid composition and shared common features of high acidic amino acid contents. © 1994 Academic Press, Inc.