Dehydrins, a family of hydrophilic and intrinsically disordered proteins, are a subgroup of late embryogenesis abundant proteins that perform different protective roles in plants. Although the transition from a disordered to an ordered state has been associated with dehydrin function or interactions with specific partner molecules, the question of how the primary and secondary dehydrin protein structure is related to specific functions or target molecule preferences remains unresolved. This work addresses the in silico sequencing analysis and in vitro functional characterization of two dehydrin isoforms, VviDHN2 and VviDHN4, from Vitis vinifera. Conformational changes suggest potential interactions with a broad range of molecules and could point to more than one function. The in silico analysis showed differences in conserved segments, specific amino acid binding sequences, heterogeneity of structural properties and predicted sites accessible for various post-translational modifications between the sequence of both dehydrins. Moreover, in vitro functional analysis revealed that although they both showed slight antifungal activity, only VviDHN4 acts as a molecular shield that protects proteins from freezing and dehydration. VviDHN4 also demonstrated high potential as a chaperone and reactive oxygen species scavenger, in addition to presenting antifreeze activity, all of which confirms its multifunctional nature. Our findings highlight the significant role of Y-segments and the differential and specific amino acid composition of less conserved segments that are rich in polar/charged residues between S- and K-segments, coupled with post-translational modifications, in modulating and switching dehydrin biological function.

脱水蛋白是一种亲水性和内在无序的蛋白家族，是晚期胚胎发生丰富蛋白的一个亚组，在植物中发挥不同的保护作用。尽管从无序状态到有序状态的转变与脱水蛋白功能或与特定伴侣分子的相互作用有关，但一级和二级脱水蛋白蛋白质结构与特定功能或靶分子偏好如何相关的问题仍未解决。这项工作解决了来自葡萄树的两种脱水蛋白同工型VviDHN2和VviDHN4的计算机测序分析和体外功能表征。构象变化表明与广泛分子的潜在相互作用，并且可能指向多个功能。的，在硅片分析表明在保守片段，特定氨基酸结合序列，结构性质的异质性和预测的位点都脱水蛋白的序列之间的各种翻译后修饰可访问的差别。而且，体外功能分析表明，尽管它们均显示出轻微的抗真菌活性，但只有VviDHN4充当分子屏障，可保护蛋白质免于冷冻和脱水。VviDHN4除具有抗冻活性外，还具有作为伴侣和活性氧清除剂的潜力，所有这些都证实了其多功能性。我们的发现突出了Y段的重要作用以及保守程度较低的节段的差异和特定氨基酸组成，这些节段富含S和K段之间的极性/带电残基，并伴随翻译后修饰，调节和转换脱水蛋白生物学功能。