Serine 71 of the glycoprotein HEF is located at the active site of the acetylesterase of influenza C virus.
The acetylesterase of influenza C virus has been reported recently to be inhibited by diisopropylfluorophosphate (DFP) [Muchmore EA, Varki A (1987) Science 236: 1293-1295]. As this inhibitor is known to bind covalently to the serine in the active site of serine esterases, we attempted to determine the serine in the active site of the influenza C acetylesterase. Incubation of purified influenza C virus with 3H-DFP resulted in the selective labelling of the influenza C glycoprotein HEF. The labelled glycoprotein was isolated from a SDS-polyacrylamide gel. Following reduction and carboxymethylation, tryptic peptides of HEF were prepared and analyzed by reversed phase HPLC. The peptide containing the 3H-DFP was subjected to sequence analysis. The amino acids determined from the NH2-terminus were used to locate the peptide on the HEF polypeptide. Radiosequencing revealed that 3H-DFP is attached to amino acid 17 of the tryptic peptide. These results indicate that serine 71 is the active-site serine of the acetylesterase of influenza C virus.
Herrler
G
G
Institut für Virologie, Philipps-Universität Marburg, Federal Republic of Germany.
Multhaup
G
G
Beyreuther
K
K
Klenk
H D
HD
D000115:Acetylesterase / Q000032:analysis* / Q000037:antagonists & inhibitors; D000595:Amino Acid Sequence; D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000032:analysis*; D009982:Gammainfluenzavirus / Q000201:enzymology*; D007531:Isoflurophate; D008969:Molecular Sequence Data; D009975:Orthomyxoviridae / Q000201:enzymology*; D012694:Serine / Q000032:analysis*; D014759:Viral Envelope Proteins / Q000032:analysis*; D014776:Virus Cultivation
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D014759:Viral Envelope Proteins; D007531:Isoflurophate; D012694:Serine; D000115:Acetylesterase