Characterization of an Alkaline Alginate Lyase with pH-Stable and Thermo-Tolerance Property
Characterization of an Alkaline Alginate Lyase with pH-Stable and Thermo-Tolerance Property
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具有 pH 稳定性和耐热性的碱性藻酸盐裂解酶的表征
DOI：
10.3390/md17050308
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发表时间：
2019-05-01
期刊：
影响因子：
5.4
通讯作者：
Li, Shangyong
中科院分区：
文献类型：
--
作者：
Wang, Yanan;Chen, Xuehong;Li, Shangyong
海藻酸寡糖（AOS）具有多种生物活性。虽然各种各样的海藻酸裂解酶已被表征，但具有特殊特性的酶仍然很少见。本研究从海洋细菌Vibrio sp. SY 01中克隆了一个多糖裂解酶家族7（PL 7）藻酸裂解酶编码基因aly 08，并在大肠杆菌中表达。纯化的海藻酸裂解酶Aly 08分子量为35 kDa，在最适pH（pH8.35）和温度（45 °C）下比活力为841 U/mg。Aly 08显示出良好的pH稳定性，因为其在宽pH范围（4.0-10.0）内保持其初始活性的80%以上。Aly 08也是一种耐热酶，在热休克处理5 min后恢复了其初始活性的70.8%。这项研究还表明，Aly 08是polyG优选的酶。此外，Aly 08以内切方式降解藻酸盐为二糖和三糖。其耐热性和pH稳定性使Aly 08成为进一步应用的良好候选者。
Alginate oligosaccharides (AOS) show versatile bioactivities. Although various alginate lyases have been characterized, enzymes with special characteristics are still rare. In this study, a polysaccharide lyase family 7 (PL7) alginate lyase-encoding gene, aly08, was cloned from the marine bacterium Vibrio sp. SY01 and expressed in Escherichia coli. The purified alginate lyase Aly08, with a molecular weight of 35 kDa, showed a specific activity of 841 U/mg at its optimal pH (pH 8.35) and temperature (45 °C). Aly08 showed good pH-stability, as it remained more than 80% of its initial activity in a wide pH range (4.0–10.0). Aly08 was also a thermo-tolerant enzyme that recovered 70.8% of its initial activity following heat shock treatment for 5 min. This study also demonstrated that Aly08 is a polyG-preferred enzyme. Furthermore, Aly08 degraded alginates into disaccharides and trisaccharides in an endo-manner. Its thermo-tolerance and pH-stable properties make Aly08 a good candidate for further applications.