Characterization of the receptor-destroying enzyme activity from infectious salmon anaemia virus.
Infectious salmon anaemia virus (ISAV) infects cells via the endocytic pathway and, like many other enveloped viruses, ISAV contains a receptor-destroying enzyme. We have analysed this acetylesterase activity with respect to substrate specificity, enzyme kinetics, inhibitors, temperature and pH stability. The ISAV acetylesterase was inhibited by di-isopropyl fluorophosphate (DFP) in a dose-dependent fashion but not by other known hydrolase inhibitors, suggesting that a serine residue is part of the active site. The pH optimum of the enzyme was in the range 7.5-8.0 and the enzymatic activity was lessened at temperatures above 40 degrees C. The effect of DFP on agglutination/elution of erythrocytes by ISAV demonstrated that the acetylesterase activity is the bona fide receptor-destroying enzyme. A haemadsorption assay was used to analyse whether the esterase was active on the surface of infected cells or not.
Kristiansen
Marianne
M
Department of Microbiology, School of Pharmacy, PO Box 1068, Blindern, 0316 Oslo, Norway1.
Frøystad
Marianne K
MK
Department of Microbiology, School of Pharmacy, PO Box 1068, Blindern, 0316 Oslo, Norway1.
Rishovd
Anne Lise
AL
Department of Microbiology, School of Pharmacy, PO Box 1068, Blindern, 0316 Oslo, Norway1.
Gjøen
Tor
T
Department of Microbiology, School of Pharmacy, PO Box 1068, Blindern, 0316 Oslo, Norway1.
D000115:Acetylesterase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000372:Agglutination Tests; D000818:Animals; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004912:Erythrocytes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007531:Isoflurophate / Q000494:pharmacology; D007700:Kinetics; D009975:Orthomyxoviridae / Q000201:enzymology*; D011991:Receptors, Virus / Q000378:metabolism*; D020317:Salmo salar; D013379:Substrate Specificity; D013696:Temperature
D004791:Enzyme Inhibitors; D011991:Receptors, Virus; D007531:Isoflurophate; D000115:Acetylesterase