Foot-and-mouth disease virus: immunogenicity and structure of fragments derived from capsid protein VP3 and of virus containing cleaved VP3

• Published in: Veterinary Microbiology (Netherlands) Vol. 7; no. 2
• Main Authors: Bachrach, H.L, Morgan, D.O, McKercher, P.D, Moor, D.M, Robertson, B.H. (Plum Island Animal Disease Center USDA, Greenport NY (USA))
• Format: Publication
• Language: English
• Published: 01.05.1982

Peptide fragments were obtained from the immunogenic capsid protein VP(,3), ca. 24 kilodaltons (kd), of foot-and-mouth disease virus type A(,12)119ab by three procedures: (1) spontaneous proteolysis of in virion VP(,3) in tissue cultures to produce to 15 kd peptide, designated S fragment; (2) trypsin treatment of purified virus to produce a 16 kd peptide, designated T fragment; and (3) cyanogen bromide cleavage of purified VP(,3) to produce a 13 kd fragment. Following isolation and purification by gel electrophoresis, VP(,3) and each of the three fragments were immunogenic for livestock. Lyophilization appeared to impair the immunogenicity of VP(,3). In addition, viruses containing VP(,3) fragments produced either by the spontaneous- or trypsin-induced proteolysis were as immunogenic as virus with its VP(,3) intact. Amino acid sequencing of N-terminal regions revealed that the S fragment was homologous with the N-terminus of VP(,3), whereas the 13 kd fragment possessed a unique N-terminus. Thus, putative common immunogenic amino acid sequences whould appear to reside within an overlap region of the 15 kd S and 13 kd fragments. Sequencing of cDNA prepared to viral genome RNA provided three kinds of information: it (1) placed the above overlap region in the second and third quarters of VP(,3); (2) demonstrated that the codons for the C-terminus of VP(,1) and N-terminus of VP(,3) are contiguous; and (3) supported earlier evidence that these same codons program a chain reversal where VP(,1) and VP(,3) are joined in the precursor polyprotein.