Coupled-Enzyme System for Measuring Viral Neuraminidase Activity

The universal epitope of influenza A viral neuraminidase fundamentally contributes to enzyme activity and viral replication.

The only universally conserved sequence among all influenza A viral neuraminidases is located between amino acids 222 and 230. However, the potential roles of these amino acids remain largely unknown. Through an array of experimental approaches including mutagenesis, reverse genetics, and growth kinetics, we found that this sequence could markedly affect viral replication. Additional experiment...

Fluorimetric coupled enzyme assay for lysoplasmalogenase activity in liver.

We developed a continuous spectrofluorimetric assay of lysoplasmalogenase activity with the use of horse liver alcohol dehydrogenase as a coupling enzyme. In this method the disappearance of NADH is measured spectrofluorimetrically. The excitation and emission monochromators were set at 340 and 460 nm respectively. The assay is 10 times as sensitive as the previous u.v. spectrophotometric metho...

Measuring autonomic nervous system activity

Attempt at use of the fluorometric neuraminidase assay system for the enzyme antibody inhibition test.

The fluorometric neuraminidase assay method using 4-methylumbelliferyl-N-Ac-aD-neuraminide as a substrate was investigated for the purpose of ascertaining its validity as a procedure for influenza viral neuraminidase antibody inhibition test. The enzyme antibody inhibition titer obtained by the fluorometric assay system was far weaker than that obtained by the standard colorimetric neuraminidas...

Neuraminidase activity in bacterial meningitis.

The relation of neuraminidase to morbidity and mortality was examined in patients with Haemophilus influenzae, meningococcal, and pneumococcal meningitis. Ten strains of H. influenzae and eight strains of meningococci from infected cerebrospinal fluid (CSF) did not elaborate neuraminidase. Each of 27 strains of pneumococci from infected CSF elaborated both neuraminidase and N-acetylneuraminic a...