研究目的
To understand the biphasic change in phasor dots of intrinsic ?uorescence of gramicidin D and gramicidin A in DMPC unilamellar and multilamellar vesicles at 0.143 gramicidin mole fraction by developing a statistical mechanical model of gramicidin/DMPC mixtures.
研究成果
The study reveals that the mole fraction of gramicidin relative to the matrix lipids is of fundamental importance for the behaviors of gramicidin/PC mixtures because membrane lateral structure can be altered significantly in a biphasic manner in the vicinity of a critical gramicidin mole fraction. The statistical mechanical model developed supports the experimental findings and provides insights into the lateral organization of gramicidin in phospholipid membranes.
研究不足
The study is limited to gramicidin/DMPC mixtures and may not be directly applicable to other lipid-peptide systems. The model assumes a sludge-like mixture of fluid phase and aggregates of rigid clusters, which may not capture all aspects of membrane dynamics.
1：Experimental Design and Method Selection:
The study involved the preparation of gramicidin/DMPC mixtures with varying gramicidin mole fractions to observe the biphasic change in phasor dots of intrinsic fluorescence. A statistical mechanical model was developed to understand the phenomenon.
2：Sample Selection and Data Sources:
Gramicidin A and D were dissolved in organic solvents and mixed with DMPC to create stock solutions. The concentrations were determined by measuring absorbance at 280 nm.
3：List of Experimental Equipment and Materials:
Equipment included a Beckman DU-640 spectrometer for absorbance measurements, a Labcono freeze-dry system for sample preparation, and an ISS K-2 multifrequency phase-modulation fluorimeter for fluorescence lifetime measurements.
4：Experimental Procedures and Operational Workflow:
Gramicidins and DMPC mixed in organic solvents were dried and hydrated using a buffer to make multilamellar vesicles (MLVs) and unilamellar vesicles (LUVs). Fluorescence lifetime measurements were conducted to observe the phasor dots.
5：Data Analysis Methods:
The phase and modulation data were presented using phasor plots, which are a convenient and model-independent way to describe complex fluorescence decays.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
