Purification and properties of poly(beta-D-mannuronate) lyase from Azotobacter chroococcum
Purification and properties of poly(beta-D-mannuronate) lyase from Azotobacter chroococcum
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DOI：
10.1007/bf00172488
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发表时间：
1996-01-01
影响因子：
5
通讯作者：
Kodama, T
中科院分区：
文献类型：
--
作者：
Haraguchi, K;Kodama, T
从土壤样品中分离出一种细菌，固氮菌4A 1 M，在培养液中产生一种藻酸盐分解酶。将酶纯化至电泳均质状态。纯化的酶在pH6.0和60 ℃下表现出最大活性;在pH6.0下，它在60 ℃下是稳定的，并且被Ca 2+激活，被Hg 2+强烈抑制。通过十二烷基硫酸钠/聚丙烯酰胺凝胶电泳估计酶的分子量为23 kDa，通过凝胶过滤估计为24 kDa。因此，该酶被认为是单体的。该酶的氨基端氨基酸序列为H_2N-Ala-Ser-Ile-Ala-Ile-Thr-Asn-Pro-Gly-Phe，反应底物为短链聚甘露糖醛酸，反应产物主要为两种。两种产物的聚合度分别为3和2。
A bacterium, Azotobacter chroococcum 4A1M, isolated from a soil sample, produced an alginate-decomposing enzyme in the culture broth. The enzyme was purified to an electrophoretically homogeneous state. The purified enzyme showed maximum activity at pH 6.0 and 60 degrees C; it was stable up to 60 degrees C at pH 6.0 and activated by Ca2+ and inhibited strongly by Hg2+. The molecular mass of the enzyme was estimated to be 23 kDa by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and 24 kDa by gel filtration. Therefore, the enzyme was considered to be monomeric. The NH2-terminal amino acid sequence was determined to be H2N-Ala-Ser-Ile-Ala-Ile-Thr-Asn-Pro-Gly-Phe enzyme reacted only on the polymannuronate block of alginic acid, and two main reaction products were obtained when short-chain polymannuronate was used as a substrate. The degrees of polymerization of the two products were three and two respectively.