Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120 Heidelberg, Germany.
Applied Physical Chemistry, Institute of Physical Chemistry, Heidelberg University, 69120 Heidelberg, Germany.
Langmuir. 2024 Oct 22;40(42):22168-22176. doi: 10.1021/acs.langmuir.4c02691. Epub 2024 Oct 10.
Sarcoplasmic reticulum (SR) membranes from rabbit muscle were deposited on silicon substrates and characterized by the combination of spectral ellipsometry (SE), high energy specular X-ray reflectivity (XRR), specular neutron reflectivity (NR), and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Following the optimization of the preparative conditions by SE, the detailed structures in the direction perpendicular to the membrane were probed by XRR. ATR-FTIR data showed strong signals from amide I and amide II bands of the native SR membranes containing a large amount of Ca-ATPase, which could not be achieved by the reconstitution in artificial lipid membranes. The treatment with protease led to a significant decrease in the amide peaks, and the XRR data confirmed the modulation of the membrane structures. The obtained data show the potential of the in situ combination of reflectivity and vibrational spectroscopy of native supported membranes in order to unravel both structure and dynamics of complex biological membranes.
兔肌肌浆网（SR）膜沉积在硅基底上，通过光谱椭圆偏振（SE）、高能镜面 X 射线反射率（XRR）、镜面中子反射率（NR）和衰减全反射傅里叶变换红外（ATR-FTIR）光谱的结合对其进行了表征。通过 SE 对制备条件进行优化后，用 XRR 探测了垂直于膜的方向上的详细结构。ATR-FTIR 数据显示，含有大量 Ca-ATPase 的天然 SR 膜在酰胺 I 和酰胺 II 带中具有很强的信号，这在人工脂质膜的再构成中是无法实现的。用蛋白酶处理会导致酰胺峰显著减少，而 XRR 数据则证实了膜结构的调节。所获得的数据表明，原位结合天然支撑膜的反射率和振动光谱具有揭示复杂生物膜的结构和动力学的潜力。
