Antipeptide antibodies directed against the carboxy-terminal region of SV40 structural proteins VP2 and VP3

Recognition of SV40-VP2 in the infected cell by antipeptide antibodies

Antipeptide antibodies were elicited against two synthetic peptides corresponding to amino acids 47-55 and 98-103 of the structural protein VP 2 of SV 40. The induced antibodies proved to be VP 2-specific in an immunoblot. In immunofluorescence these antibodies showed a discrete nuclear and perinuclear staining pattern. In immune electron microscopy studies the induced antibodies did not bind to major virions suggesting that VP 2 is not present at the surface of SV 40 particles.

A synthetic peptide corresponding to the cleavage region of VP3 from rotavirus SA11 induces neutralizing antibodies

Antibodies were elicited in rabbits by immunization with the synthetic tetradecapeptide Gln-Asn-Thr-Arg-Asn-Ile-Val-Pro-Val-Ser-Ile-Val-Ser-Arg, corresponding to amino acids 228 to 241 of SA11-VP3. Protein specificity of the antipeptide serum is demonstrated. The antipeptide serum revealed neutralizing activity directed against SA11 in a neutralization assay. Human rotavirus strains Wa, S2, and Hochi and bovine strains NCDV and UK were not neutralized, demonstrating the strain-specific neutralizing activity of the raised antipeptide serum. Upon immune electron microscopy, aggregation of SA11 particles was observed.

Three amino acids of a heptapeptide-induced antibody are responsible for recognition of SV40 structural proteins

Antibodies were elicited against the heptapeptide Asp-His-Lys-Val-Ser-Thr-Val. The sequence of the heptapeptide corresponds to amino acid residues 105-111 of Simian Virus 40 (SV40) structural protein VP2. The antipeptide antibodies recognize VP2 and amino acid sequence Asp-His-Lys (193-195) in VP1 at different degrees of denaturation. Inhibition experiments were performed with the heptapeptide as well as with the tripeptide Asp-His-Lys. Using this model system, the specificity and selectivity of peptide-induced antibodies can be demonstrated with a resolution of a single amino acid.

Myristic acid is coupled to a structural protein of polyoma virus and SV40

In the lytic cycle of papova viruses, both uncoating of the viral genome after infection and assembly of functional virions take place in the cell nucleus. The mechanisms by which newly internalized virions are targeted to the nucleus and viral DNA encapsidated into particles are poorly understood. Although the major capsid protein VP1 is involved in endocytosis, and largely defines virion structure, the functions of the minor proteins VP2 and VP3 have remained obscure. Here we show that VP2 from both polyoma virus and simian virus 40 (SV40) is covalently linked to myristic acid; this is the first report of a myristylated protein in the nucleus and of a fatty acid being important in the structure of a nonenveloped virus. We consider the implications of this unusual modification on encapsidation and suggest that VP2 may be a scaffolding protein for virion assembly.