Mohammad-Beigi Hossein, Kjaer Lars, Eskandari Hoda, Aliakbari Farhang, Christiansen Gunna, Ruvo Gianluca, Ward Jane L, Otzen Daniel Erik
Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus, Denmark.
Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
Front Plant Sci. 2019 Feb 13;10:148. doi: 10.3389/fpls.2019.00148. eCollection 2019.
The ability of proteins to aggregate to form well-organized β-sheet rich amyloid fibrils is increasingly viewed as a general if regrettable property of the polypeptide chain. Aggregation leads to diseases such as amyloidosis and neurodegeneration in humans and various mammalian species but is also found in a functional variety in both animals and microbes. However, there are to our knowledge no reports of amyloid formation in plants. Plants are also the source of a large number of aggregation-inhibiting compounds. We reasoned that the two phenomena could be connected and that one of (many) preconditions for plant longevity is the ability to suppress unwanted protein aggregation. In support of this, we show that while protein extracts from the sugar maple tree fibrillate readily on their own, this process is efficiently abolished by addition of small molecule extracts from the same plant. Further analysis of 44 plants showed a correlation between plant longevity and ability to inhibit protein aggregation. Extracts from the best performing plant, the sugar maple, were subjected to chromatographic fractionation, leading to the identification of a large number of compounds, many of which were shown to inhibit aggregation . One cautious interpretation is that it may have been advantageous for plants to maintain an efficient collection of aggregation-inhibiting metabolites as long as they do not impair metabolite function. From a practical perspective, our results indicate that long-lived plants may be particularly appropriate sources of new anti-aggregation compounds with therapeutic potential.
蛋白质聚集形成结构良好且富含β-折叠的淀粉样纤维的能力，越来越被视为多肽链的一种普遍特性，尽管令人遗憾。聚集会导致人类和各种哺乳动物出现诸如淀粉样变性和神经退行性变等疾病，但在动物和微生物中也发现其具有多种功能。然而，据我们所知，尚无关于植物中淀粉样蛋白形成的报道。植物也是大量聚集抑制化合物的来源。我们推测这两种现象可能存在关联，并且植物长寿的（众多）前提条件之一是能够抑制不必要的蛋白质聚集。为此，我们表明，虽然糖枫的蛋白质提取物自身很容易形成纤维，但加入同一植物的小分子提取物后，这一过程会被有效抑制。对44种植物的进一步分析表明，植物的寿命与抑制蛋白质聚集的能力之间存在相关性。对表现最佳的植物糖枫的提取物进行色谱分离，从而鉴定出大量化合物，其中许多被证明具有抑制聚集的作用。一种谨慎的解释是，只要不损害代谢物功能，植物维持高效的聚集抑制代谢物集合可能是有利的。从实际角度来看，我们的结果表明，长寿植物可能是具有治疗潜力的新型抗聚集化合物的特别合适来源。
