关于通过两种方法获得的甲型流感病毒A（H3N2）神经氨酸酶的研究。

Neuraminidase was obtained by (A) bromelain solubilization or (B) by treatment with N-lauroylsarcosine. 2. 5-N-acetyl-2-O-(3-methoxyphenyl)-alpha-D-neuraminic acid, employed as substrate, avoids the interference produced by the thiobarbituric acid method, and is not interfered by the ampholytes. 3. Only about 20% of original enzyme activity was lost after electrofocusing. The sample from procedure A showed two peaks, corresponding to pIs 4.4 and 5.6. The sample from procedure B, having a higher activity, showed only one peak at pI 4.4. 4. Samples A and B showed different Km and hydrolysis rate with N-acetylneuraminyl-lactose and glycophorin A. It was not found significantly different with other substrates: alpha 1-acid glycoprotein, brain gangliosides, 5-N-acetyl-2-O-(3-methoxyphenyl)-alpha-D-neuraminic acid and 2'-(4-methyl umbelliferyl)-alpha-D-N-acetylneuraminic acid.

神经氨酸酶可通过（A）菠萝蛋白酶增溶法或（B）用N-月桂酰肌氨酸处理获得。2. 用作底物的5-N-乙酰-2-O-（3-甲氧基苯基）-α-D-神经氨酸可避免硫代巴比妥酸法产生的干扰，且不受两性电解质干扰。3. 等电聚焦后，原始酶活性仅损失约20%。方法A的样品显示出两个峰，对应于pI 4.4和5.6。方法B的样品活性较高，在pI 4.4处仅显示一个峰。4. 样品A和B对N-乙酰神经氨酰乳糖和血型糖蛋白A显示出不同的Km值和水解速率。与其他底物：α1-酸性糖蛋白、脑苷脂、5-N-乙酰-2-O-（3-甲氧基苯基）-α-D-神经氨酸和2'-（4-甲基伞形酮基）-α-D-N-乙酰神经氨酸相比，未发现显著差异。

Studies on neuraminidase from influenza virus A(H3N2) obtained by two procedures.