NA Protein (Native, Influenza B)

Measured by its ability to cleave a fluorogenic substrate, 2’- (4-Methylumbelliferyl) -α-D-N-acetylneuraminic acid. One unit is defined as the amount of enzyme required to cleave 1 nmole of 2'- (4-Methylumbelliferyl) -α-D-N-acetylneuraminic acid per minute at pH 7.5 at 37°C.