Comparative study of influenza virus H2 (Asian) hemagglutinins isolated from human and avian sources.

The hemagglutinin of an influenza virus isolated from a wild duck (Pintail, Anas acuta) in the USSR in 1976 had been found to be antigenically indistinguishable from the hemagglutinin of H2N2 viruses of human origin isolated in 1957. The hemagglutinins from viral preparations of the A/Anas acuta/Primorie/695/76 (H2Nav2) and A/Singapore/1/57 (H2N2) strains were purified by SDS gel chromatography as the subunits HA1 and HA2. Comparison of amino acid compositions and peptide maps of tryptic peptides containing [14C]-carboxymethylcysteine showed a striking degree of similarity between the H2 hemagglutinins.

Amino terminal sequence of hog intrinsic factor.

1. Hog intrinsic factor has been purified from gastric mucosa by labile ligand affinity chromatography. 2.

Primary structure of human intrinsic factor: progress report on cyanogen bromide fragmentation.

Human intrinsic factor purified by labile ligand affinity chromatography was cleaved with cyanogen bromide and fractionated by gel filtration. Four of the fragments were purified and sequenced to a total of eighty-four amino acid residues. Including the N-terminal amino acids this amounts to one third of the total amino acid sequence of human intrinsic factor.

Purification and characterization of rabbit transcobalamin II.

Rabbit transcobalamin II has been purified by labile ligand affinity chromatography and G-200 Sephadex gel filtration. Structural studies indicate Stokes' radii of 2.7 nm and 3.

Purification of neuraminidase from influenza viruses by affinity chromatography.

The neuraminidase (acylneuraminyl hydrolase, EC 3.2.1.

An improved procedure for automated Edman degradation used for determination of the N-terminal amino acid sequence of human transcobalamin I and human intrinsic factor.

An improved procedure for automated Edman degradation is presented. Three programs are described, one with double cleavage and two with single cleavage. The programs presented are characterized by a reversed delivery scheme for buffer and phenyl isothiocyanate, and by reduced cleavage times.

Chromatographic isolation of the hemagglutinin polypeptides from influenza virus vaccine and determination of their amino-terminal sequences.

The influenza virus hemagglutinin polypeptides, HA1 and HA2, have been purified by gel filtration in the presence of sodium dodecyl sulfate from a vaccine preparation of the recombinant strain Heq1N2. Use of this technique for purification of the hemagglutinin polypeptides eliminated the need for proteolytic agents for removal of the hemagglutinin from the virus particles and 100-300 mg of virus yielded 10-30 mg of viral protein per chromatographic cycle. Because proteolysis is not required to remove the spikes from the viral envelope, the envelope-embedded HA2 polypeptide was purified in its entirety for structural analysis.

Applications of a synthetic neuraminidase substrate.

A rapid and precise assay for neuraminidase using 2-(3'-methoxyphenyl)-N-acetyl-alpha-neuraminic acid (MPN) is described. It is proposed that this substrate be used for the standardization of activity of neuraminidases from viral, bacterial, and mammalian sources. MPN is also used as a chromogenic substrate to localize influenza and parainfluenza virus foci in tissue culture.

A 2 (N2) neuraminidase of the X-7 influenza virus recombinant: determination of molecular size and subunit composition of the active unit.

Neuraminidase activity of influenza virus was directly seen on sodium dodecyl sulfate polyacrylamide gels with the aid of the synthetic substrate, methoxyphenol neuraminic acid. Neuraminidase (NA) appeared as a high-molecular-weight fraction with a size in the range of 220,000 to 250,000 daltons. Isolation of this fraction from the X-7 strain of influenza virus, dissociation with sodium dodecyl sulfate, and reduction showed the presence of two polypeptides of 66,000 (NA(1)) and 58,000 (NA(2)) molecular weights in equimolar concentration.