Virus inactivation and protein modifications by ethyleneimines

Virus inactivation by ethyleneimines was first introduced more than 30 year s ago. Selective targeting of nucleic acids was reported for oligomeric eth yleneimines. In this study, trimeric ethyleneimine (TEI) was used to inacti vate minute virus of mice (MVM Parvoviridae) and Semliki forest virus (SFV, Togaviridae). The pH-dependency of the inactivation kinetics observed with MVM was different compared to the kinetics reported for other viruses. The higher inactivation rate at higher pH favoured the idea of a mechanism inv olving protein modifications. Alteration of the isoelectric point and chang es in mass could be observed after treatment of soluble proteins with TEL T he uptake of MVM by host cells was reduced or completely blocked by TEI tre atment, as shown by monitoring viral internalisation of DNA into target cel ls. The observed loss of virus infectivity coincided with the inhibition of virus uptake. Thus, virus inactivation by TEI is most likely also a result of chemical modifications of viral surface proteins. (C) 2001 Elsevier Sci ence B.V. All rights reserved.