Oxidative conjugation of catechols with proteins in insect skeletal systems
Oxidative conjugation of catechols with proteins in insect skeletal systems
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DOI：
10.1016/s0040-4020(00)00949-2
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发表时间：
2001-01-07
期刊：
影响因子：
2.1
通讯作者：
Turecek, F
中科院分区：
文献类型：
--
作者：
Kramer, KJ;Kanost, MR;Turecek, F
角质层硬化或鞣制是发生在昆虫发育的每个阶段的重要过程，以硬化和稳定新分泌的外骨骼。结构聚合物蛋白质和甲壳素构成了角质层的主体，并且这些生物聚合物与五羟甲基鞣剂之间的化学相互作用在很大程度上是成熟外骨骼的物理性质的原因。儿茶酚与表皮蛋白的氧化结合在这种代谢中起着重要作用。角质层硬化的主要假设涉及蛋白质中组氨酰残基的亲核咪唑氮与邻醌和对醌甲基化物的亲电子环或侧链碳之间形成加合物和交联，邻醌和对醌甲基化物来源于儿茶酚、N-乙酰多巴胺、N-β-丙氨酰多巴胺和3，4-二羟基苯基乙醇。已经阐明了这些醌鞣剂与来自几个目的各种昆虫的铜蛋白质之间的C-N和C-O键，已经分离和测序了催化交联反应的酪氨酸酶和漆酶类型的酚氧化酶的cDNA。两种昆虫漆酶的cDNA序列与真菌漆酶的相似性高于植物漆酶。这些结果提供了深入了解昆虫如何使用结构蛋白，儿茶酚，氧化酶形成儿茶酚氨基酸加合物在硬化。出版社：Elsevier Science Ltd
Cuticle sclerotization or tanning is a vital process that occurs during each stage of insect development to harden and stabilize the newly secreted exoskeleton. The structural polymers protein and chitin make up the bull; of the cuticle, and chemical interactions between these biopolymers with quinonoid tanning agents are largely responsible for the physical properties of the mature exoskeleton. The oxidative conjugation of catechols with cuticular proteins plays an important role in this metabolism. The main hypothesis for cuticle sclerotization involves the formation of adducts and cross-links between nucleophilic imidazole nitrogens of histidyl residues in the proteins and electrophilic ring or side-chain carbons of ortho-quinones and para-quinone methides derived from the catechols, N-acetyldopamine, N-beta-alanyldopamine, and 3,4-dihydroxyphenylethanol. C-N and C-O linkages between these quinone tanning agents and proteins in cuticles from a variety of insects from several orders have been elucidated, cDNAs for both the tyrosinase and laccase types of phenoloxidases that catalyze the cross-linking reactions have been isolated and sequenced. The sequences of laccase cDNAs from two insect species were more similar to fungal laccases than to those from plants. These results provide insights into how insects use structural proteins, catechols, and oxidative enzymes to form catechol-amino acid adducts during sclerotization. Published by Elsevier Science Ltd.