Conformational Change in Herpes Simplex Virus Entry Glycoproteins Detected by Dot Blot

Conformational changes in viral membrane proteins drive membrane fusion, a critical step in virus entry and infection. Here we describe a simple and rapid virus blotting immunoassay to define conformational changes with a panel of monoclonal antibodies to distinct sites across a viral glycoprotein. This dot blot technique has been utilized to define low pH-triggered changes in the prefusion form of the herpesviral fusogen gB. At pH of <6.2 there are specific changes in herpes simplex virus 1 gB domains I and V. This corresponds broadly to host cell endosomal pH. Many of the identified changes are at least partially reversible. This method can be adapted to document changes in viral proteins that are not fusion proteins, including those induced by alternate triggers such as receptor-binding or protease cleavage.