Binding of herpes simplex virus (HSV) type 1 to the various subclasses of human serum lipoproteins was investigated. Studies were performed with human serum lipoproteins purified by differential ultracentrifugation and artificial proteoliposomes containing only one type of apolipoprotein (A1, E) by using an enzyme-linked immunosorbent assay technique, column chromatography, and electron microscopy. All tested lipoprotein subclasses (very low, low-, high-density lipoproteins; VLDL, LDL, HDL, HDL1) showed significant binding of purified HSV type 1. Furthermore, HSV bound to all different synthetic proteoliposomes. Adsorption of envelope proteins isolated from purified HSV to Sepharose-bound lipoproteins revealed binding of HSV glycoprotein B. Based on these results we reached the conclusion that in HSV-lipoprotein complex formation the lipid component in the lipoproteins and the glycoprotein B in HSV are the preferential reaction partners.