Characterization of neuraminidase-resistant mutants derived from rotavirus porcine strain OSU.
Infection by some rotavirus strains requires the presence of sialic acid on the cell surface, its infectivity being reduced in cells treated with neuraminidase. A neuraminidase treatment-resistant mutant was isolated from the porcine rotavirus strain OSU. In reassortant strains, the neuraminidase-resistant phenotype segregated with the gene coding for VP4. The mutant retained its capacity to bind to sialic acid. The VP4 sequence of the mutant differed from that of the parental OSU strain in an Asp-to-Asn substitution at position 100. Neutralization escape mutants selected from an OSU neuraminidase-sensitive clone by monoclonal antibodies that failed to recognize the neuraminidase-resistant mutant strain carried the same mutation at position 100 and were also neuraminidase resistant. Neuraminidase sensitivity was restored when the mutation at position 100 was compensated for by a second mutation (Gln to Arg) at position 125. Molecular mechanics simulations suggest that the neuraminidase-resistant phenotype associated with mutation of OSU residue 100 from Asp to Asn reflects the conformational changes of the sialic acid cleft that accompany sialic acid binding.
López
José Agustín
JA
Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apartado postal 21827, Caracas 1020-A, Venezuela.
Maldonado
Antonio José
AJ
Gerder
Marlene
M
Abanero
José
J
Murgich
Juan
J
Pujol
Flor H
FH
Liprandi
Ferdinando
F
Ludert
Juan Ernesto
JE
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D036022:Capsid Proteins / Q000737:chemistry / Q000502:physiology; D002460:Cell Line; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009439:Neuraminidase / Q000494:pharmacology*; D011487:Protein Conformation; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D012401:Rotavirus / Q000737:chemistry / Q000235:genetics*; D013552:Swine / Q000821:virology*; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000378:metabolism
D000911:Antibodies, Monoclonal; D036022:Capsid Proteins; D016601:RNA-Binding Proteins; C060339:VP4 protein, Rotavirus; D017361:Viral Nonstructural Proteins; C079234:NS35 protein, rotavirus; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid