Purification and characterization of an acetyl xylan esterase produced by Streptomyces lividans
Purification and characterization of an acetyl xylan esterase produced by Streptomyces lividans
复制标题
DOI：
10.1042/bj3190881
复制
发表时间：
1996-11-01
影响因子：
4.1
通讯作者：
Kluepfel, D
中科院分区：
文献类型：
--
作者：
Dupont, C;Daigneault, N;Kluepfel, D
从过量生产菌株S的培养物滤液中纯化从变铅青链霉菌同源克隆的乙酰木聚糖酯酶[Shareck，Biely，Morosoli和Kluepfel（1995）Gene 153，105-109]。lividans IAF 43.分泌的酶的分子量为34 kDa，pI为9.0。在化学乙酰化桦木木聚糖的测定条件下，该酶的动力学常数为：比活性，715单位/mg，K-m 7.94 mg/ml和V-max 1977单位/mg。在70 ℃和pH 7.5下获得最佳酶活性。不同乙酰化底物的水解试验表明，该酶是特异性的O-乙酰基多糖的脱乙酰基，是缺乏N-脱乙酰活性。顺序水解表明，它的作用是必不可少的完全降解乙酰化木聚糖的木聚糖酶的S。橄榄色。
The acetyl xylan esterase cloned homologously from Streptomyces lividans [Shareck, Biely, Morosoli and Kluepfel (1995) Gene 153, 105-109] was purified from culture filtrate of the overproducing strain S. lividans IAF43. The secreted enzyme had a molecular mass of 34 kDa and a pI of 9.0. Under the assay conditions with chemically acetylated birchwood xylan the kinetic constants of the enzyme were: specific activity, 715 units/mg, K-m 7.94 mg/ml and V-max 1977 units/mg. Optimal enzyme activity was obtained at 70 degrees C and pH 7.5. Hydrolysis assays with different acetylated substrates showed that the enzyme is specific for deacetylating the O-acetyl group of polysaccharides and is devoid of N-deacetylation activity. Sequential hydrolysis shows that its action is essential for the complete degradation of acetylated xylan by the xylanases of S. lividans.