Studies on the neuraminidase of influenza virus

The discovery of polyribosomes

“…In 1959, little was known other than the presence of two antigens, hemagglutinin and neuraminidase, on the viral surface and that the enzymatic activity could be split from the virus particle by the action of trypsin, (4) yet the molecular properties of both proteins were unknown. A sensitive assay for neuraminidase, based on the release of neuraminic acid from the trisaccharide neuraminlactose had just been published (5,6) and its isolation from cow colostrums had been described earlier.…”

Variation in the membrane-insertion and "stalk" sequences in eight subtypes of influenza type A virus neuraminidase

“…The NA heads which project from the surface can be removed from some strains of influenza virus by digestion with proteases and recovered with complete antigenic and enzymic activity (Mayron et al, 1961;Noll et al, 1962; Wilson & Rafelson, 1963;Drzeniek et al, 1966;Rafelson et al, 1966;Setoet al, 1966; Kendal & Kiley, 1973;Laver, 1978). These heads do not aggregate which indicates that the hydrophobic region of the NA is lost upon protease cleavage, and they also appear by electron microscopy to have lost the thin stalk (Wrigley et al, 1973).…”

Antiviral adhesion molecular mechanisms for influenza: W. G. Laver's lifetime obsession

“…However, in 1961, Mayron and his colleagues found that a soluble sialidase could be separated from particles of influenza virus and that the soluble enzyme had no HA activity and did not adsorb to red cells [14]. Around the same time, Hans Noll found that if influenza type B virus was treated with trypsin, almost 100% of the NA was liberated as a soluble enzyme with a sedimentation coefficient of 9S (MW about 200 kDa) leaving all of the HA activity associated with the virus particles [15].…”