Comprehensive enzymatic analysis of the amylolytic system in the digestive fluid of the sea hare, Aplysia kurodai: Unique properties of two α-amylases and two α-glucosidases.
Comprehensive enzymatic analysis of the amylolytic system in the digestive fluid of the sea hare, Aplysia kurodai: Unique properties of two α-amylases and two α-glucosidases.
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DOI：
10.1016/j.fob.2014.06.002
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发表时间：
2014
期刊：
影响因子：
2.6
通讯作者：
Yuasa, Keizo
中科院分区：
文献类型：
--
作者：
Tsuji, Akihiko;Nishiyama, Nami;Ohshima, Miki;Maniwa, Saori;Kuwamura, Shuji;Shiraishi, Masataka;Yuasa, Keizo
研究了海兔（Aplysia kurodai）消化液的淀粉分解系统。从消化液中纯化出两种α-淀粉酶和两种α-葡萄糖苷酶。海兔通过这些酶的组合有效地将海生菜消化成葡萄糖。海生菜中的淀粉是海兔的主要葡萄糖来源。海生菜（Ulva pertusa）是一种令人讨厌的绿藻，在世界各地都有发现。东亚海洋腹足动物海兔（Aplysia kurodai）对海生菜表现出明显的摄食偏好。与纤维素相比，海生菜含有较高量的淀粉作为储存多糖。然而，A. kurodai消化液中的整个淀粉分解系统尚未得到详细研究。我们从 A. kurodai 的消化液中纯化了 α-淀粉酶和 α-葡萄糖苷酶，并研究了这些酶对海生菜的协同作用。 A. kurodai 含有两种 α-淀粉酶（59 和 80 kDa）和两种 α-葡萄糖苷酶（74 和 86 kDa）。 Ca2+ 或 Cl− 显着激活 59 kDa α-淀粉酶，但 80 kDa α-淀粉酶则不然。两种 α-淀粉酶都能降解淀粉和麦芽七糖，产生麦芽三糖、麦芽糖和葡萄糖。使用 80-kDa α-淀粉酶从淀粉中生产的葡萄糖高于使用 59-kDa α-淀粉酶的淀粉。动力学分析表明，74-kDa α-葡萄糖苷酶更喜欢短的 α-1,4-连接寡糖，而 86-kDa α-葡萄糖苷酶更喜欢大的 α-1,6 和 α-1,4-连接多糖，例如糖原。当使用海生菜作为底物时，用 59-kDa α-淀粉酶和 74-kDa α-葡萄糖苷酶处理释放的葡萄糖量比用 A. kurodai 的 45-kDa 纤维素酶和 210-kDa β-葡萄糖苷酶处理释放的葡萄糖量高 2 倍。与哺乳动物不同，海兔通过消化液中两种 α-淀粉酶和两种 α-葡萄糖苷酶的组合，有效地将海生菜消化为葡萄糖，而无需膜结合的麦芽糖酶-葡萄糖淀粉酶和蔗糖酶-异麦芽糖酶复合物。
The amylolytic system of the digestive fluid of sea hare (Aplysia kurodai) was studied. Two α-amylases and two α-glucosidases were purified from the digestive fluid. Sea hare efficiently digests sea lettuce to glucose by a combination of these enzymes. Starch in sea lettuce is a predominant glucose source for sea hare. Sea lettuce (Ulva pertusa) is a nuisance species of green algae that is found all over the world. East-Asian species of the marine gastropod, the sea hare Aplysia kurodai, shows a clear feeding preference for sea lettuce. Compared with cellulose, sea lettuce contains a higher amount of starch as a storage polysaccharide. However, the entire amylolytic system in the digestive fluid of A. kurodai has not been studied in detail. We purified α-amylases and α-glucosidases from the digestive fluid of A. kurodai and investigated the synergistic action of these enzymes on sea lettuce. A. kurodai contain two α-amylases (59 and 80 kDa) and two α-glucosidases (74 and 86 kDa). The 59-kDa α-amylase, but not the 80-kDa α-amylase, was markedly activated by Ca2+ or Cl−. Both α-amylases degraded starch and maltoheptaose, producing maltotriose, maltose, and glucose. Glucose production from starch was higher with 80-kDa α-amylase than with 59-kDa α-amylase. Kinetic analysis indicated that 74-kDa α-glucosidase prefers short α-1,4-linked oligosaccharide, whereas 86-kDa α-glucosidase prefers large α-1,6 and α-1,4-linked polysaccharides such as glycogen. When sea lettuce was used as a substrate, a 2-fold greater amount of glucose was released by treatment with 59-kDa α-amylase and 74-kDa α-glucosidase than by treatment with 45-kDa cellulase and 210-kDa β-glucosidase of A. kurodai. Unlike mammals, sea hares efficiently digest sea lettuce to glucose by a combination of two α-amylases and two α-glucosidases in the digestive fluids without membrane-bound maltase–glucoamylase and sucrase–isomaltase complexes.
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影响因子：
4.1
作者：
BUONOCORE, V;POERIO, E;TOMASI, M
通讯作者：
TOMASI, M
影响因子：
3.8
作者：
Price, D. R. G.;Karley, A. J.;Douglas, A. E.
通讯作者：
Douglas, A. E.
影响因子：
2.9
作者：
Qian, MX;Ajandouz, E;Nahoum, V
通讯作者：
Nahoum, V
影响因子：
8
作者：
BRAYER, GD;LUO, YG;WITHERS, SG
通讯作者：
WITHERS, SG
DOI：
10.1016/j.cbpb.2008.12.007
发表时间：
2009-03-01
影响因子：
2.2
作者：
Nikapitiya, Chamilani;Oh, Chulhong;Lee, Jehee
通讯作者：
Lee, Jehee