Centro de Análises Bioquímicas e Proteômicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, DF 70790-160, Brazil.
Laboratório de RMN, Instituto de Química, Universidade Federal de Goiás, Goiânia, GO 74690-900, Brazil
Biochem J. 2018 Nov 9;475(21):3359-3375. doi: 10.1042/BCJ20180213.
Among the numerous strategies plants have developed to fend off enemy attack, antimicrobial peptides (AMPs) stand out as one of the most prominent defensive barriers that grant direct and durable resistance against a wide range of pests and pathogens. These small proteins are characterized by a compact structure and an overall positive charge. AMPs have an ancient origin and widespread occurrence in the plant kingdom but show an unusually high degree of variation in their amino acid sequences. Interestingly, there is a strikingly conserved topology among the plant AMP families, suggesting that the defensive properties of these peptides are not determined by their primary sequences but rather by their tridimensional structure. To explore and expand this idea, we here discuss the role of AMPs for plant defense from a structural perspective. We show how specific structural properties, such as length, charge, hydrophobicity, polar angle and conformation, are essential for plant AMPs to act as a chemical shield that hinders enemy attack. Knowledge on the topology of these peptides is facilitating the isolation, classification and even structural redesign of AMPs, thus allowing scientists to develop new peptides with multiple agronomical and pharmacological potential.
在植物为抵御敌人攻击而发展出的众多策略中，抗菌肽 (AMPs) 是最突出的防御屏障之一，它们能直接且持久地抵抗多种害虫和病原体。这些小分子蛋白质具有紧凑的结构和整体正电荷。AMPs 具有古老的起源和在植物界中的广泛存在，但它们的氨基酸序列却表现出异常高的变异性。有趣的是，植物 AMP 家族之间存在着惊人的保守拓扑结构，这表明这些肽的防御特性不是由其一级序列决定，而是由其三维结构决定。为了探索和扩展这一想法，我们从结构的角度讨论了 AMPs 在植物防御中的作用。我们展示了特定的结构特性，如长度、电荷、疏水性、极性角和构象，对于 AMPs 作为阻碍敌人攻击的化学盾牌是必不可少的。这些肽的拓扑结构知识正在促进 AMPs 的分离、分类甚至结构重新设计，从而使科学家能够开发具有多种农艺和药理学潜力的新型肽。
