Characterization and serology of the matrix protein from a nuclear-polyhedrosis virus of Trichoplusia ni before and after degradation by an endogenous proteinase.
The intact matrix protein from a nuclear-polyhedrosis virus of the cabbage looper (Trichoplusia ni), isolated after inhibition of an endogenous serine-type proteinase, was further purified by molecular-sieve chromatography. The matrix protein was associated with carbohydrate moieties, and the carbohydrate content was determined for the two major peptides isolated after proteolysis by the endogenous proteinase. The association-dissociation interactions of the intact and proteinase-hydrolysed monomer units were characterized at high and low pH. At pH1.9, proteinase-degraded matrix protein dissociated into two different peptide fractions, FI and FII. Fraction FII, a single peptide of 9400 daltons, comprised one-third of the monomer unit of 28 000 daltons. At pH9.5, the degraded peptides were tightly associated in units equivalent to the intact monomer. These monomer equivalents associated to form a series of interconverting aggregates. The predominant aggregate sedimented at 11S and had a mol.wt greater than or equal to 200 000. Two non-cross-reacting antigens were present in the aggregate mixture. The presence of these two antigens does not reflect the presence of two different matrix proteins; rather, the expression of the antigens correlates with the degree of aggregation of the matrix protein.
D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D004247:DNA / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007304:Insect Viruses / Q000378:metabolism*; D046911:Macromolecular Substances; D010447:Peptide Hydrolases / Q000378:metabolism*; D010710:Phosphates / Q000032:analysis; D014764:Viral Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*
D000596:Amino Acids; D002241:Carbohydrates; D046911:Macromolecular Substances; D010710:Phosphates; D014764:Viral Proteins; D004247:DNA; D010447:Peptide Hydrolases