Contribution to the standardization of influenza neuraminidase inhibition tests, based on enzyme- antienzyme kinetic studies.
1. From enzyme-antienzyme kinetic studies a method for the determination of anti-n2-neuraminidase antibodies has been developed. This procedure is applicable in routine diagnosis. 2. Considering the present conditions, the reversibility of the virus neuraminidase antigen-antineuraminidase antibody complex has been proved. The inhibition must be described as a non-competitive one. 3. As a reference value for comparative immunity estimations the relative antibody concentration T150 is defined as the point of reciprocal serum dilution, where under a given substrate concentration the inhibited enzyme activity vi is half of the non-inhibited enzyme activity vo. 4. For the calculation of T150 a simple formula is derived from the Michaelis-Menten kinetic. Under present conditions the value of T150 is in a range of 1.5 log 2 dilution steps plus or minus the specific serum dilution T150 uninfluenced by possible variable parameters such as enzyme activity, substrate concentration and inhibitor concentration.
D000906:Antibodies / Q000032:analysis*; D006023:Glycoproteins / Q000378:metabolism; D006385:Hemagglutination Inhibition Tests; D007700:Kinetics; D009438:Neuraminic Acids / Q000032:analysis / Q000378:metabolism; D009439:Neuraminidase / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000378:metabolism; D009975:Orthomyxoviridae / Q000201:enzymology; D014734:Vibrio cholerae / Q000201:enzymology
D000906:Antibodies; D006023:Glycoproteins; D009438:Neuraminic Acids; D009439:Neuraminidase