The regulation of trehalose metabolism in insects
The regulation of trehalose metabolism in insects
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DOI：
10.1007/bf01919312
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发表时间：
1996-05-01
期刊：
影响因子：
--
通讯作者：
Wegener, G
中科院分区：
文献类型：
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作者：
Becker, A;Schloder, P;Wegener, G
海藻糖是由两个葡萄糖分子组成的非还原性二糖。它作为昆虫的主要血淋巴（血液）糖以高浓度存在。脂肪体（一种功能类似于脊椎动物肝脏和脂肪组织组合的器官）中海藻糖的合成受到心体（一种与大脑相关的神经血液器官）释放的神经肽（高海藻酸血症激素）的刺激。这些肽导致脂肪体细胞中果糖2，6-二磷酸的含量降低。果糖2，6-二磷酸，与AMP协同作用，是糖酵解酶6-磷酸果糖激酶-1的有效激活剂和产酶果糖1，6-二磷酸酶的强抑制剂。这表明2，6-二磷酸果糖是调节昆虫海藻糖合成的关键代谢信号。海藻糖被海藻糖酶（E. C. 3.2.1.28）。这种酶的活性在飞行肌肉中受到调节，但实现这一点的机制尚不清楚。摘要蝗虫飞行肌海藻糖酶是一种与微粒体膜结合的糖蛋白。该酶可以在体外被洗涤剂激活，在体内被短的飞行间隔激活，这表明在生理条件下膜环境的变化调节海藻糖酶活性。
Trehalose is a non-reducing disaccharide comprising two glucose molecules. It is present in high concentration as the main haemolymph (blood) sugar in insects. The synthesis of trehalose in the fat body (an organ analogous in function to a combination of liver and adipose tissue in vertebrates) is stimulated by neuropeptides (hypertrehalosaemic hormones), released from the corpora cardiaca, a neurohaemal organ associated with the brain. The peptides cause a decrease in the content of fructose 2,6-bisphosphate in fat body cells. Fructose 2,6-bisphosphate, acting synergistically with AMP, is a potent activator of the glycolytic enzyme 6-phosphofructokinase-1 and a strong inhibitor of the gluconeogenic enzyme fructose 1,6-bisphosphatase. This indicates that fructose 2,6-bisphosphate is a key metabolic signal in the regulation of trehalose synthesis in insects. Trehalose is hydrolysed by trehalase (E.C. 3.2.1.28). The activity of this enzyme is regulated in flight muscle, but the mechanism by which this is achieved is unknown. Trehalase from locust flight muscle is a glycoprotein bound to membranes of the microsomal fraction. The enzyme can be activated by detergents in vitro and by short flight intervals in vivo, which indicates that changes in the membrane environment modulate trehalase activity under physiological conditions.