Tsujibo H, Yoshida Y, Miyamoto K, Imada C, Okami Y, Inamori Y
Osaka University of Pharmaceutical Sciences, Japan.
Can J Microbiol. 1992 Sep;38(9):891-7. doi: 10.1139/m92-145.
Chitinase (EC 3.2.1.14) was isolated from the culture supernatant of a marine bacterium, Alteromonas sp. strain O-7. The enzyme (Chi-A) was purified by anion-exchange chromatography (DEAE-Toyopearl 650 M) and gel filtration (Sephadex G-100). The purified enzyme showed a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The molecular size and pI of Chi-A were 70 kDa and 3.9, respectively. The optimum pH and temperature of Chi-A were 8.0 and 50 degrees C, respectively. Chi-A was stable in the range of pH 5-10 up to 40 degrees C. Among the main cations, such as Na+, K+, Mg2+, and Ca2+, contained in seawater, Mg2+ stimulated Chi-A activity. N-Bromosuccinimide and 2-hydroxy-5-nitrobenzyl bromide inhibited Chi-A activity. The amino-terminal 27 amino acid residues of Chi-A were sequenced. This enzyme showed sequence homology with chitinases from terrestrial bacteria such as Serratia marcescens QMB1466 and Bacillus circulans WL-12.
几丁质酶（EC 3.2.1.14）是从海洋细菌嗜碱交替单胞菌（Alteromonas sp.）菌株O-7的培养上清液中分离得到的。该酶（Chi-A）通过阴离子交换色谱法（DEAE- Toyopearl 650 M）和凝胶过滤法（Sephadex G-100）进行纯化。纯化后的酶在十二烷基硫酸钠聚丙烯酰胺凝胶电泳上显示出单一的条带。Chi-A的分子大小和等电点分别为70 kDa和3.9。Chi-A的最适pH值和温度分别为8.0和50℃。Chi-A在pH 5-10范围内、40℃以下时稳定。在海水中所含的主要阳离子（如Na+、K+、Mg2+和Ca2+）中，Mg2+能刺激Chi-A的活性。N-溴代琥珀酰亚胺和2-羟基-5-硝基苄基溴可抑制Chi-A的活性。对Chi-A的氨基末端27个氨基酸残基进行了测序。该酶与来自陆生细菌（如粘质沙雷氏菌QMB1466和环状芽孢杆菌WL-12）的几丁质酶具有序列同源性。
