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(MPS)是一组生物分子，其功能是转运底物穿过细胞膜。最广泛的MPS家族之一是三磷酸腺苷结合盒(ABC)转运体。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)-已知可以运输包括阿霉素等化疗活性药物在内的多种底物。这些MPS的过度表达与化疗失败和多药耐药有关，使得结构和功能特征对药物开发至关重要。不幸的是，由于MPS的疏水性，MPS的研究具有挑战性。传统上，在包装到离散胶束中之前，洗涤剂被用来从膜上去除MPS。然而，这种方法引起了人们的担忧，因为蛋白质-脂质相互作用的中断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)的替代方法已变得流行起来。它们自我插入到膜中，隔离嵌有MPS的脂类片段--称为SMA脂粒(SMALP)或DIBMA脂粒(DIBMALP)。这项研究旨在利用基于聚合物的增溶作用来研究ABC转运蛋白的蛋白质-脂质相互作用的基础。这将通过评估不同脂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转运蛋白增溶的最佳聚合物，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.