Lipid environment of membrane proteins in cryo-EM based structural analysis
Kazuhiro Mio1,2, Chikara Sato3
1AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Chiba, 277-8568, Japan. kazu.mio@aist.go.jp.
Biophysical Reviews
|December 20, 2017
Summary
Cryoelectron microscopy (cryo-EM) with single particle analysis (SPA) advances protein structure determination. New sample preparation techniques improve membrane protein structure resolution in cryo-EM studies.
Area of Science:
- Structural Biology
- Biophysics
- Biochemistry
Background:
- Cryoelectron microscopy (cryo-EM) coupled with single particle analysis (SPA) is a powerful technique for determining protein and macromolecular complex structures.
- Advancements in direct electron detection and image processing have enabled near-atomic to atomic resolution structure determination, overcoming challenges like difficult crystallization or low protein yield.
- Determining the high-resolution structures of membrane proteins using cryo-EM has been historically challenging due to the use of detergents, which obscure protein density and reduce contrast.
Purpose of the Study:
- This review focuses on recent improvements in sample preparation techniques for cryo-electron microscopy (cryo-EM) studies of membrane proteins.
- The primary interest is in methods that better mimic the native lipid environment of membrane proteins to enhance structural analysis.
- To address the limitations posed by detergent micelles in cryo-EM of membrane proteins.
Main Methods:
- Review of recent advancements in cryo-EM sample preparation techniques.
- Focus on methods designed to preserve the native membrane environment for proteins.
- Analysis of strategies to improve contrast and reduce artifacts from detergent solubilization.
Main Results:
- Significant improvements in sample preparation techniques have been achieved for cryo-EM studies.
- New methods effectively mimic the lipid environment, enhancing the quality of cryo-EM data for membrane proteins.
- These advancements facilitate higher resolution structure determination of membrane proteins.
Conclusions:
- Improved sample preparation is crucial for high-resolution cryo-EM structure determination of membrane proteins.
- Techniques mimicking the native lipid environment are key to overcoming previous resolution limitations.
- The reviewed advancements promise to expand the scope of cryo-EM in membrane protein structural biology.
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