Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan.
J Microbiol Biotechnol. 2013 Jun 28;23(6):872-7. doi: 10.4014/jmb.1301.01075.
In a previous study, we isolated and reported a second species of the Saccharophagus genus, Saccharophagus sp. strain Myt-1. In the present study, an alginate lyase gene (algMytC) from the genomic DNA of Myt-1 was cloned and characterized. The DNA sequence fragment obtained contained an open reading frame of 1,032 bp that encoded a protein of 343 amino acids with an estimated molecular mass of 37.6 kDa and a pI of 6.60. The deduced protein, AlgMytC, had the conserved amino acid sequences (RTELREM, QIH, YFKAGVYNQ) of the polysaccharide lyase family 7. A BLAST homology search indicated that AlgMytC shared an amino acid sequence identity of 95.9% with alg7A of S. degradans 2-40. The cloned and purified AlgMytC protein showed optimal activity at 40°C, and retained more than 90% of its total activity even after treatment at 25°C for 24 h. AlgMytC was very alkaliphilic with an optimal pH of 9.0, and more than 90% of its activity was retained in the pH range 8.5-10.0. Moreover, AlgMytC was stable over a wide pH range. The activity of AlgMytC was also stable in the presence of various detergents.
在之前的研究中，我们分离并报道了 Saccharophagus 属的第二个种 Saccharophagus sp. strain Myt-1。在本研究中，从 Myt-1 的基因组 DNA 中克隆并表征了一种褐藻胶裂解酶基因（algMytC）。获得的 DNA 序列片段包含一个 1032bp 的开放阅读框，编码一个 343 个氨基酸的蛋白质，估计分子量为 37.6kDa，等电点为 6.60。推断的蛋白 AlgMytC 具有多糖裂解酶家族 7 的保守氨基酸序列（RTELREM、QIH、YFKAGVYNQ）。BLAST 同源性搜索表明，AlgMytC 与 S. degradans 2-40 的 alg7A 具有 95.9%的氨基酸序列同一性。克隆和纯化的 AlgMytC 蛋白在 40°C 下表现出最佳活性，在 25°C 下处理 24 小时后仍保留超过 90%的总活性。AlgMytC 具有很强的碱性，最适 pH 为 9.0，在 pH8.5-10.0 范围内保留超过 90%的活性。此外，AlgMytC 在较宽的 pH 范围内稳定。AlgMytC 的活性在存在各种洗涤剂时也很稳定。
