4-MUNANA (solution)

4-MUNANA (solution) is a substrate of influenza virus neuraminidase (NA) with high selectivity and irreversible reaction. In the enzymatic reaction, 4-MUNANA is hydrolyzed by NA to generate fluorescent 4-methylumbelliferone (4-MU). By detecting the fluorescence intensity of 4-MU, quantitative analysis of NA activity can be achieved. 4-MUNANA can be used in influenza-related research, such as screening NA inhibitors, developing new anti-influenza drugs, and studying the infection mechanism of influenza viruses^[1][2].
Solution Concentration: 10 mM In Vitro:In the experiment of screening neuraminidase inhibitors of traditional Chinese medicine, 4-MUNANA (50 μg/mL; react with NA for 30 minutes) can be used to evaluate the activity of NA by detecting the fluorescence intensity of 4-Methylumbelliferone (4-M) generated by its reaction with NA, thereby screening out traditional Chinese medicines such as Bupleurum Root that have inhibitory effects on NA, and determining their active ingredients and IC₅₀^[1].
The specific steps are as follows:
First, immerse the test strip in the stock solution for 30 seconds, then take it out and react with different concentrations of neuraminidase (NA) for 30 minutes.
After the reaction is completed, observe the fluorescence changes of the test strip under 365 nm light and record the image with a smartphone. At the same time, different concentrations of NA were added to the 4-MUNANA solution and allowed to react for 30 minutes. The fluorescence intensity of the 4-MU generated by the reaction was then measured (Ex=365 nm, Em=445 nm). This was used to establish a standard curve of NA concentration and fluorescence value for evaluating NA activity.
When screening NA inhibitors in Chinese herbal extracts, the Chinese herbal extracts were first reacted with NA, and then 4-MUNANA was added. The inhibitory effect of the extracts on NA was determined by detecting changes in fluorescence intensity.
4-MUNANA (0.025 mM; reacted with NA for 10 minutes) was used to measure the enzyme activity of NA in an experiment to study the functional balance between HA and NA of influenza viruses. The results showed that there was a functional balance between the activities of HA and NA in human pandemic viruses, while swine-derived viruses often deviated from this balance^[2].
The specific steps are as follows:
The reaction was carried out in a reaction buffer containing 100mM imidazole-malic acid (pH 6.15)，150mM NaCl, 10mM CaCl2, 0.1mg/mL bovine serum albumin and 0.02% NaN3. 4-MUNANA was used as a substrate, and its concentration was 0.025 mM when used in the experiment to compare the enzyme activity under different NA concentrations. The total reaction volume was 80μL, and the reaction was carried out at room temperature (22°C) for 10 minutes, followed by the addition of 80μl 1M Na2CO3 to terminate the reaction. Finally, the concentration of the reaction product was measured (Ex=365 nm, Em=450 nm) to determine the enzyme activity of NA and study the relationship between the functional balance of HA and NA in influenza virus and virus transmission.