Khorlin I Ia, Vertiev V V, Ezepchuk Ia M, Privalova I M, Kvaratskheliia L D
Biokhimiia. 1975 Jul-Aug;40(4):819-23.
Enzymatic properties of neuraminidase isolated from non-toxigenic strain C7 of diphteritic bacteria are studied. The enzyme has the pH optimum 5.5--6.0 in acetate buffer and the temperature optimum 38 degrees C. Neuraminidase has the highest substrate affinity to glycoproteins of equine blood serum, the lowest affinity--to 3-N-acetylneuraminosyllactose and ovomucin. The Km values was 4.3-10(-4) at optimal conditions under the hydrolysis of 3-N-acetylneuraminosyllactose, Vm was 0.05+/-0.02 muM NANA/hour/mg of protein. The following esters of N-glyconoyl-glycine were shown to be competitive inhibitors of neuraminidase: 1) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-arabinooctonic acid; 2) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-glucoheptodecanic acid; 3) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-galactonic acid; 4) methyl ester of 3-aza-4-oxo-2,3,4-trideoxy-D-gluconic acid, Ki values being 6.5-10(-4), 4.5-10(-4); 9.5-10(-4) and 7.1-(10-3) M, respectively.
研究了从无毒白喉杆菌C7菌株中分离出的神经氨酸酶的酶学特性。该酶在醋酸盐缓冲液中的最适pH为5.5 - 6.0，最适温度为38℃。神经氨酸酶对马血清糖蛋白的底物亲和力最高，对3 - N - 乙酰神经氨酰乳糖和卵粘蛋白的亲和力最低。在最佳条件下水解3 - N - 乙酰神经氨酰乳糖时，Km值为4.3×10⁻⁴，Vm为0.05±0.02 μM NANA/小时/毫克蛋白质。以下N - 糖酰甘氨酸酯被证明是神经氨酸酶的竞争性抑制剂：1）3 - 氮杂 - 4 - 氧代 - 2,3,4 - 三脱氧 - D - 阿拉伯辛糖酸甲酯；2）3 - 氮杂 - 4 - 氧代 - 2,3,4 - 三脱氧 - D - 葡庚糖酸甲酯；3）3 - 氮杂 - 4 - 氧代 - 2,3,4 - 三脱氧 - D - 半乳糖酸甲酯；4）3 - 氮杂 - 4 - 氧代 - 2,3,4 - 三脱氧 - D - 葡萄糖酸甲酯，Ki值分别为6.5×10⁻⁴、4.5×10⁻⁴、9.5×10⁻⁴和7.1×10⁻³ M。
