Investigation into the basis of protein-lipid interactions for ATP-Binding Cassette (ABC) transporters BmrA and P-gp, using novel polymer-based solubi

膜蛋白（MP）是一组生物分子，其功能是作为转运蛋白将底物穿过细胞膜。最广泛的MP家族之一是ATP结合盒（ABC）转运蛋白。ABC转运蛋白超家族的两个同源成员-枯草芽孢杆菌多药耐药ABC转运蛋白（BmrA）和P-糖蛋白（P-gp）-已知转运多种底物，包括化学活性药物，如阿霉素。这些MP的过表达与化疗失败和多药耐药性有关，使得结构和功能表征对于药物开发至关重要。不幸的是，由于其疏水性，MP的研究具有挑战性。传统上，洗涤剂用于在包装成离散胶束之前从膜中除去MP。然而，这种方法引起了人们的关注，因为蛋白质-脂质相互作用的破坏已被证明会影响蛋白质的结构和功能。因此，涉及合成聚合物如苯乙烯马来酸（SMA）和二异丁烯马来酸（DIBMA）的替代方法变得流行。它们自我插入膜中，分离嵌入MP的脂质片段-称为SMA脂质颗粒（SMALP）或DIBMA脂质颗粒（DIBMALP）。本研究的目的是利用聚合物为基础的增溶调查的基础上ABC转运蛋白的蛋白质-脂质相互作用。这将通过评估不同脂质组成的蛋白质-脂质体中的蛋白质结构和功能来实现。我们还旨在确定ABC转运蛋白溶解的最佳聚合物，以简化蛋白质生产并支持基于聚合物的方法。

Membrane proteins (MPs) are a group of biomolecules that function as transporters to move substrates across a cell membrane. One of the most widespread families of MPs are ATP-Binding Cassette (ABC) transporters. Two homologous members of the ABC transporter superfamily -Bacillus subtilis multidrug resistance ABC transporter (BmrA) and P-glycoprotein (P-gp)- are known to transport a wide variety of substrates including chemo-active drugs such as doxorubicin. Overexpression of these MPs has been linked to chemotherapeutic failure and multi-drug resistance, making structural and functional characterisation critical for drug development. Unfortunately, the study of MPs is challenging due to their hydrophobicity. Traditionally, detergents were utilised to remove MPs from a membrane before packaging into discrete micelles. However, this method raises concerns as the disruption of protein-lipid interactions has been shown to influence protein structure and function. Alternative methods involving synthetic polymers such as Styrene Maleic Acid (SMA) and Diisobutylene-Maleic Acid (DIBMA) have therefore become popular. They self-insert into the membrane, isolating segments of lipids with MPs embedded - known as SMA Lipid Particles (SMALPs) or DIBMA Lipid Particles (DIBMALPs). This study aims to utilise polymer-based solubilisation to investigate the basis of protein-lipid interactions for ABC transporters. This will be accomplished by assessing protein structure and function in proteo-liposomes of varying lipid compositions. We also aim to identify the optimal polymers for ABC transporter solubilisation to streamline protein production and support polymer-based methodology.