Abstract

Metal pollutants are a growing concern due to increased use in mining and other industrial processes. Moreover, the use of metals in daily life is becoming increasingly prevalent. Metals such as manganese (Mn), cobalt (Co), and nickel (Ni) are toxic in high amounts whereas lead (Pb) and cadmium (Cd) are acutely toxic at low µM concentrations. These metals are associated with system dysfunction in humans including cancer, neurodegenerative diseases, Alzheimer’s disease, Parkinson’s disease, and other cellular process’. One known but lesser studied target of these metals are lipids that are key membrane building blocks or serve signalling functions. It was shown that Mn, Co, Ni, Pb, and Cd cause rigidification of liposomes and increase the phase transition in membranes composed of both saturated or partly unsaturated phosphatidic acid (PA) and phosphatidylserine (PS). The selected metals showed differential effects that were more pronounced on saturated lipids. In addition, more rigidity was induced in the biologically relevant liquid-crystalline phase. Moreover, metal affinity, induced rigidification and liposome size increases also varied with the headgroup architecture, whereby the carboxyl group of PS appeared to play an important role. Thus, it can be inferred that Mn, Co, Ni, Cd, and Pb may have preferred binding coordination with the lipid headgroup, degree of acyl chain unsaturation, and membrane phase.

中文翻译：

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必需金属离子和有毒金属离子与生物相关磷脂酸和磷脂酰丝氨酸膜的不同相互作用

摘要

由于采矿和其他工业过程中金属污染物的使用增加，金属污染物日益受到关注。此外，金属在日常生活中的使用变得越来越普遍。锰 (Mn)、钴 (Co) 和镍 (Ni) 等金属在高浓度时具有毒性，而铅 (Pb) 和镉 (Cd) 在低 µM 浓度时具有剧毒。这些金属与人类系统功能障碍有关，包括癌症、神经退行性疾病、阿尔茨海默病、帕金森病和其他细胞过程。这些金属的一个已知但较少研究的目标是脂质，它是关键的膜构建块或发挥信号传导功能。结果表明，Mn、Co、Ni、Pb 和 Cd 会导致脂质体硬化，并增加由饱和或部分不饱和磷脂酸 (PA) 和磷脂酰丝氨酸 (PS) 组成的膜中的相变。所选金属表现出不同的影响，对饱和脂质的影响更为明显。此外，在生物学相关的液晶相中诱导了更多的刚性。此外，金属亲和力、诱导刚性和脂质体尺寸的增加也随头基结构的不同而变化，其中 PS 的羧基似乎发挥了重要作用。因此，可以推断Mn、Co、Ni、Cd和Pb可能与脂质头基、酰基链不饱和度和膜相具有优选的结合配位。