天然细胞膜中膜转运蛋白的动态结构的相关研究数据

底物通过膜转运蛋白的过程是一个动态过程，涉及不同功能构象之间的转换，而这一过程可能因非天然膜模拟环境的影响而受阻。在天然细胞膜内捕获这些构象及其转换状态仍面临显著挑战。本研究采用原位固态核磁共振技术，成功解析了BjSemiSWEET在天然细胞膜内的1.5Å外向开放构象与2.5Å闭合构象。研究结果表明，这两种构象在跨膜螺旋TM1与环区L2-3上以毫秒至秒级的时间尺度进行动态交换，且交换速率与蔗糖转运速率相匹配。分子动力学模拟进一步证实这些构象代表了蔗糖转运过程中的功能状态。与此形成对比的是，在DMPC/DMPG合成磷脂双层膜环境中，BjSemiSWEET呈现出与细胞膜环境不同的构象动态特性。本研究凸显了原位固态核磁共振技术在揭示细胞分子过程中未知动态结构信息的潜力，标志着动态细胞结构生物学领域的重要进展。

The transport of substrates across membrane transporters is a dynamic process involving transitions between distinct functional conformations, which can be hindered by non-native membrane-mimetic environments. Capturing these conformations and their transition states within native cell membranes still poses significant challenges. In this study, we employed in situ solid-state nuclear magnetic resonance (ssNMR) and successfully resolved the 1.5 Å outward-open conformation and 2.5 Å closed conformation of BjSemiSWEET within native cell membranes. The results demonstrate that these two conformations undergo dynamic exchange on millisecond to second timescales at the transmembrane helix TM1 and loop region L2-3, and the exchange rate matches the sucrose transport rate. Molecular dynamics (MD) simulations further confirmed that these conformations represent the functional states during sucrose transport. In contrast, in the DMPC/DMPG synthetic phospholipid bilayer membrane environment, BjSemiSWEET exhibits conformational dynamic properties distinct from those in native cell membrane environments. This study highlights the potential of in situ solid-state NMR technology in uncovering unknown dynamic structural information underlying cellular molecular processes, marking an important advancement in the field of dynamic cellular structural biology.

搜集汇总

背景与挑战

背景概述

本数据集总结了一项关于膜转运蛋白动态结构的研究，采用原位固态核磁共振技术，在天然细胞膜中解析了BjSemiSWEET蛋白的两种功能构象（1.5Å外向开放和2.5Å闭合），并发现这些构象以毫秒至秒级时间尺度动态交换，交换速率与蔗糖转运速率匹配。研究还通过分子动力学模拟确认了构象的功能状态，并对比了合成膜环境的不同动态特性，突出了该技术在揭示细胞分子过程动态结构方面的潜力。