Abstract：
The oxidation of the cellular membrane through lipid peroxidation (LPO) is linked to aging and disease. Despite the physiological importance, the chemical mechanisms underlying LPO and oxidative reactions in membranes in general remain incompletely understood, and challenges exist in translating LPO inhibitor efficacies from in vitro to in vivo. The complexity of LPO, including multiple oxidation reactions in complex membrane environments and the difficulty in quantifying reaction kinetics, underlies these difficulties. In this work, we developed a robust and straightforward method for quantifying the oxidation rate kinetics of fluorescent molecules and determined the oxidation kinetics of widely fluorophores used as indicators of membrane LPO, diphenylhexatriene (DPH), BODIPY-C11, and Liperfluo. The measurement is initiated by lipoxygenase, which provides chemical specificity and enables a straightforward interpretation of oxidation kinetics. Our results reveal that the membrane composition significantly impacts the observed kinetics oxidation in DPH and BODIPY-C11 but not Liperfluo. Reaction mechanisms for their lipid peroxide-induced oxidation are proposed. This work provides a foundation for the quantitative analysis of LPO with fluorescence and extricating the complexity of oxidation reactions within membranes.
摘要：
细胞膜通过脂质过氧化(LPO)的氧化与衰老和疾病有关。尽管生理上很重要，LPO和膜中的氧化反应的基本化学机理仍未完全了解，并且在将LPO抑制剂功效从体外转化为体内方面存在挑战。LPO的复杂性，包括复杂膜环境中的多个氧化反应和量化反应动力学的困难，这些困难的根源。在这项工作中,我们开发了一种强大而直接的方法来量化荧光分子的氧化速率动力学，并确定了广泛用作膜LPO指标的荧光团的氧化动力学，二苯基己三烯(DPH),BODIPY-C11和Liperfluo.测量由脂加氧酶启动，它提供了化学特异性，并能够直接解释氧化动力学。我们的结果表明，膜组成显着影响DPH和BODIPY-C11中观察到的动力学氧化，而不是Liperfluo。提出了脂质过氧化物诱导氧化的反应机理。这项工作为具有荧光的LPO的定量分析提供了基础，并减轻了膜内氧化反应的复杂性。
