The finding that the human proteins annexin V, tubulin and apolipoprotein B bind to the hepatitis C virus envelope proteins E1 and/or E2 and the usage of these human proteins to diagnose and treat an infection with hepatitis C virus are described. The usage of the latter proteins to enrich HCV envelope proteins and molecules which inhibit binding of HCV to these human proteins, as well as vaccines employing the E1 and/or E2 binding domains are also disclosed.