Abstract: A truncation of the human LDL receptor gene has been created which can be expressed in a heterologous host to produce a soluble fragment to the receptor protein. The gene can be expressed in insect cells in culture to produce a protein fragment which is not only water soluble but which also retains affinity for binding to LDL. The truncation is a truncation of the carboxyl terminus of the native LDL receptor gene which results in a 354 amino acid protein fragment designated LDL-R.sup.354.

Abstract: A human lipid-associated plasma protein has been produced in vivo in larvae of the Sphingid insect tobacco hornworm, Manduca sexta. The gene for the protein was introduced by recombinant Baculovirus into the body cavity of the larvae, which is a semi-permissive host for the virus. After the larvae had grown further, the hemolymph of the larvae was recovered. The yield of protein produced was much better than could be achieved for the same gene expressed in insect cell culture and a much higher percentage of the protein produced in vivo was associated in lipid particles as compared to the cell culture system. The desired biological activity of the lipid-associated protein was achieved by the in vivo produced protein but not by the protein produced by insect cells in culture.