Molecular and phylogenetic analyses of the haemagglutinin (H) proteins of field isolates of canine distemper virus from naturally infected dogs.

Abstract

We isolated three strains of canine distemper virus (CDV) -the Ueno, Hamamatsu, and Yanaka strains -from dogs in Japan and analysed the molecular properties of their haemagglutinin (H) proteins. Immunoprecipitation of all three strains with a monoclonal antibody revealed H proteins with molecular masses of 84 kDa, which differs from the molecular mass (78 kDa) of the H protein of the Onderstepoort vaccine strain. However, after tunicamycin treatment immunoprecipitation identified H proteins of identical molecular mass (68 kDa) for all three field isolates and the vaccine strain. Sequence analysis showed nine potential sites for asparagine-linked glycosylation in the H proteins of

The Nucleotide and Predicted Amino Acid Sequence of the Fusion Protein of Recent Isolates of Canine Distemper Virus in Japan.

“…The genetic relationship was closer between the recent field isolates, the Yanaka strain and PDV-2, than between the Yanaka and Onderstepoort vaccine strains. These data were in agreement with the result from the H genes [14], and suggest a progressive evolution in wild-type CDV isolates. The significant alteration of PDV-2 F gene was noted as the lack of the third ATG triplet at positions nt 461 to 463 [28], which is selectively required for in vitro translation of the Onderstepoort F gene [6].…”

“…4) in contrast to the finding that the glycosylation properties of the H proteins varied between the isolates and the vaccine strains [14]. The similar molecular sizes revealed by the immunoprecipitation analysis may provide the evidence of the same glycosylation properties of these F proteins.…”

“…In our previous study, we first analyzed the alterations of H proteins of recent field isolates from vaccine viruses, and showed that their genetic properties were significantly distinguishable from the vaccine strains [14]. In the present study, we analyzed the molecular properties of the F proteins among CDV strains in an attempt to understand the possible role of this protein in the epidemiology of the current outbreaks of CD.…”

“…The three strains of field isolates, the Ueno, Hamamatsu and Yanaka [14], were analyzed. The Onderstepoort strain was used as a standard laboratory strain.…”

“…A radioimmunoprecipitation (RIP) assay using the MAbs a-8 and b-8 was performed as described previously [14]. nucleotide sequence was determined for two clones.…”