Lee Dong-Geun, Park Geun-Tae, Kim Nam Young, Lee Eo-Jin, Jang Min Kyung, Shin Young Gyun, Park Gwang-Seok, Kim Tae-Min, Lee Jae-Hwa, Lee Jung-Hyun, Kim Sang-Jin, Lee Sang-Hyeon
Department of Pharmaceutical Engineering, College of Medical Life Sciences, Silla University, Busan, Korea.
Biotechnol Lett. 2006 Dec;28(23):1925-32. doi: 10.1007/s10529-006-9171-y. Epub 2006 Sep 23.
The gene for a thermostable beta-agarase from Agarivorans sp. JA-1 was cloned and sequenced. It comprised an open reading frame of 2,988 base pairs, which encode a protein of 109,450 daltons consisting of 995 amino acid residues. A comparison of the entire sequence showed that the enzyme has 98.8% sequence similarities to beta-agarase from Vibrio sp. JT1070, indicating that it belongs to the family glycoside hydrolase (GH)-50. The gene corresponding to a mature protein of 976 amino acids was inserted and expressed in Escherichia coli. The recombinant beta-agarase was purified to homogeneity. It had maximal activity at 40 degrees C and pH 8.0 in the presence of 1 mM NaCl and 1 mM CaCl(2). The enzyme hydrolyzed agarose as well as neoagarohexaose and neoagarotetraose to yield neoagarobiose as the main product. Thus, the enzyme would be useful for the industrial production of neoagarobiose.
克隆并测序了来自琼胶ivorans sp. JA-1的一种耐热β-琼胶酶的基因。它包含一个2988个碱基对的开放阅读框，编码一个由995个氨基酸残基组成、分子量为109450道尔顿的蛋白质。对整个序列的比较表明，该酶与来自弧菌属sp. JT1070的β-琼胶酶有98.8%的序列相似性，表明它属于糖苷水解酶（GH）-50家族。将对应于976个氨基酸成熟蛋白的基因插入并在大肠杆菌中表达。重组β-琼胶酶被纯化至同质。在1 mM NaCl和1 mM CaCl₂存在下，它在40℃和pH 8.0时具有最大活性。该酶水解琼脂糖以及新琼脂六糖和新琼脂四糖，以新琼脂二糖作为主要产物。因此，该酶将有助于新琼脂二糖的工业化生产。
