Department 7.1 Radiometry with Synchrotron Radiation and, Department 7.2 X-Ray Metrology with Synchrotron Radiation, Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587, Berlin, Germany.
ELETTRA - Sincrotrone Trieste, S.S.14 Km 163.5 in Area Science Park, 34149, Basovizza, Trieste, Italy.
Chemphyschem. 2022 Feb 16;23(4):e202100815. doi: 10.1002/cphc.202100815. Epub 2022 Jan 14.
Synchrotron radiation-based Fourier transform infrared spectroscopy enables access to vibrational information from mid over far infrared to even terahertz domains. This information may prove critical for the elucidation of fundamental bio-molecular phenomena including folding-mediated innate host defence mechanisms. Antimicrobial peptides (AMPs) represent one of such phenomena. These are major effector molecules of the innate immune system, which favour attack on microbial membranes. AMPs recognise and bind to the membranes whereupon they assemble into pores or channels destabilising the membranes leading to cell death. However, specific molecular interactions responsible for antimicrobial activities have yet to be fully understood. Herein we probe such interactions by assessing molecular specific variations in the near-THz 400-40 cm range for defined helical AMP templates in reconstituted phospholipid membranes. In particular, we show that a temperature-dependent spectroscopic analysis, supported by 2D correlative tools, provides direct evidence for the membrane-induced and folding-mediated activity of AMPs. The far-FTIR study offers a direct and information-rich probe of membrane-related antimicrobial interactions.
基于同步辐射的傅里叶变换红外光谱技术可获取从中红外到远红外甚至太赫兹区域的振动信息。这些信息可能对阐明基本的生物分子现象至关重要，包括折叠介导的先天宿主防御机制。抗菌肽（AMPs）就是这样的现象之一。它们是先天免疫系统的主要效应分子，有利于攻击微生物膜。AMPs 识别并结合到膜上，然后组装成孔或通道，破坏膜的稳定性，导致细胞死亡。然而，负责抗菌活性的特定分子相互作用尚未完全理解。在这里，我们通过评估在重建的磷脂膜中定义的螺旋 AMP 模板在近太赫兹 400-40cm 范围内的分子特异性变化来探究这些相互作用。具体来说，我们表明，温度依赖性光谱分析得到二维相关工具的支持，为 AMPs 的膜诱导和折叠介导的活性提供了直接证据。远 FTIR 研究为与膜相关的抗菌相互作用提供了直接且信息丰富的探针。
