胚胎晚期富集蛋白与生物的干旱胁迫耐受性

Functions of late embryogenesis abundant proteins in desiccation-tolerance of organisms: a review

摘要:

胚胎晚期富集蛋白 (Late embryogenesis abundant，LEA) 是参与生物体抵抗干旱胁迫的一类重要蛋白。LEA蛋白可分为7组。大多数LEA蛋白具有亲水性及热稳定性。LEA蛋白在水溶液中通常为无折叠状态，但脱水胁迫可诱导其转变为α-螺旋。近年来关于LEA蛋白的研究取得了较多进展。研究结果表明LEA蛋白可定位于细胞内的多种细胞器中，且LEA蛋白可能具有多重保护作用，如保护蛋白质及酶活性、或保护细胞的膜结构、或具有抗氧化作用、结合离子或保护DNA等。以下主要介绍了LEA蛋白的功能、二级结构及保护作用机制。

Abstract:

Late embryogenesis abundant (LEA) proteins are well associated with the desiccation tolerance in organisms. LEA proteins are categorized into at least seven groups by virtue of similarities in their deduced amino acid sequences. Most of the LEA proteins have the characteristics of high hydrophilicity and thermo-stability. The LEA proteins are in unstructured conformation in aqueous solution. However, they adopted amphiphilic α-helix structure during desiccation condition. LEA proteins are localized to the different organelles in the cells, i.e. cytoplasm, endoplasmic reticulum, mitochondria and nucleus. The multi-functional capacity of LEA proteins are suggested, as protein stabilization, protection of enzyme activity, membrane association and stabilization, antioxidant function, metal-ion binding or DNA protection, etc. Here, we review the structural and functional characteristics of LEA proteins to provide a reference platform to understand their protective mechanisms during the adaptive response to desiccation in organisms.