title: Protease treatment and chemical crosslinking of a flavivirus: tick borne encephalitis virus.
abstract: Tick-borne encephalitis virus was treated with pronase or thermolysin. The resulting particles were banded in sucrose gradients and analyzed for polypeptide composition. Both enzymes caused a reduction in particle density from 1.19 to 1.15--1.16 g/cm3. No loss of viral lipid or nucleic acid could be observed. SDS-polyacrylamidegel electrophoresis showed that only the core protein V2 was unchanged whereas the envelope proteins V3 and V1 had disappeared from their original positions in the PAGE profile. Instead a new peptide(s) with molecular weight of 4000--6000 was found in which hydrophobic amino-acids were enriched. Crosslinking by dimethyl-3.3'-dithiobispropionimidate (DTBP) made the virus resistent to solubilization of the envelope proteins by TX-100. This could be interpreted by the formation of a dense envelope protein network around the nucleocapsid preventing its liberation by TX-100. Some data however indicate that direct crosslinking of at least one of the envelope proteins with the core cannot be excluded.
mesh_terms: D003432:Cross-Linking Reagents / Q000494:pharmacology; D004220:Disulfides / Q000494:pharmacology; D004669:Encephalitis Viruses, Tick-Borne / Q000187:drug effects / Q000648:ultrastructure*; D007096:Imidoesters / Q000494:pharmacology; D010455:Peptides / Q000032:analysis; D011092:Polyethylene Glycols / Q000494:pharmacology; D011402:Pronase / Q000378:metabolism; D011487:Protein Conformation; D012995:Solubility; D013820:Thermolysin / Q000378:metabolism; D014764:Viral Proteins / Q000032:analysis*
chemical_list: D003432:Cross-Linking Reagents; D004220:Disulfides; D007096:Imidoesters; D010455:Peptides; D014764:Viral Proteins; D011092:Polyethylene Glycols; D011402:Pronase; D013820:Thermolysin