Increased influenza A virus sialidase activity with N-acetyl-9-O-acetylneuraminic acid-containing substrates resulting from influenza C virus O-acetylesterase action

Virus Res. 1992 Sep 1;25(1-2):145-53. doi: 10.1016/0168-1702(92)90106-j.


Influenza virus type C (Johannesburg/1/66) was used as a source for the enzyme O-acetylesterase (EC with several natural sialoglycoconjugates as substrates. The resulting products were immediately employed as substrates using influenza virus type A [(Singapore/6/86) (H1N1) or Shanghai/11/87 (H3N2)] as a source for sialidase (neuraminidase, EC A significant increase in the percentage of sialic acid released was found when the O-acetyl group was cleaved by O-acetylesterase activity from certain substrates (bovine submandibular gland mucin, rat serum glycoproteins, human saliva glycoproteins, mouse erythrocyte stroma, chick embryonic brain gangliosides and bovine brain gangliosides). A common feature of all these substrates is that they contain N-acetyl-9-O-acetylneuraminic acid residues. By contrast, no significant increase in the release of sialic acid was detected when certain other substrates could not be de-O-acetylated by the action of influenza C esterase, either because they lacked O-acetylsialic acid (human glycophorin A, alpha 1-acid glycoprotein from human serum, fetuin and porcine submandibular gland mucin) or because the 4-O-acetyl group was scarcely cleaved by the viral O-acetylesterase (equine submandibular gland mucin). The biological significance of these facts is discussed, relative to the infective capacity of influenza C virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylesterase / metabolism*
  • Influenza A virus / enzymology*
  • Influenzavirus C / enzymology*
  • Neuraminidase / metabolism*
  • Sialic Acids
  • Substrate Specificity


  • Sialic Acids
  • 9-O-acetyl-N-acetylneuraminic acid
  • Acetylesterase
  • Neuraminidase