A fragment of the low density lipoprotein receptor encompassing the seven ligand binding repeats was expressed in Sf9 insect cells as a fusion protein with a carboxyl-terminally linked hexa-his tag by using a baculovirus vector. Up to 10 mg/l of the fusion protein was secreted into the medium. The material was soluble in the absence of detergent and active in binding beta very low density lipoprotein and a member of the minor group of human rhinoviruses (HRV2) in ligand blots from sodium dodecyl sulfate-polyacrylamide gels run under nonreducing conditions. The receptor fragment specifically inhibits viral infection of HeLa cells by minor group HRVs in a concentration-dependent manner. Viral infectivity is neutralized by aggregation.