Related Experiment Video
Updated: Jul 16, 2026
14:55
Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Forced folding and structural analysis of metastable proteins
Ronald W Peterson1, Karthik Anbalagan, Cecilia Tommos
1Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, USA.
Journal of the American Chemical Society
|August 5, 2004
Summary
Many human proteins are unfolded in vitro, hindering structural studies. Encapsulating proteins in reverse micelles forces folding, enabling characterization via NMR spectroscopy and advancing structural proteomics.
Area of Science:
- Biochemistry
- Structural Biology
- Proteomics
Background:
- A substantial proportion of proteins from various genomes are intrinsically disordered or unfold under in vitro conditions.
- This unfolding presents a significant challenge for traditional structural biology techniques like X-ray crystallography and solution Nuclear Magnetic Resonance (NMR) spectroscopy.
- Characterizing the structure of these metastable proteins is crucial for understanding their function and for large-scale structural proteomics initiatives.
Purpose of the Study:
- To develop a novel method for inducing and stabilizing the folded state of metastable proteins in vitro.
- To enable the structural characterization of previously intractable unfolded or partially folded proteins using advanced NMR spectroscopy.
- To investigate the nature of unfolded protein states by manipulating the microenvironment within reverse micelles.
Main Methods:
- Utilizing reverse micelles as nanoreactors to encapsulate metastable proteins.
- Employing Nuclear Magnetic Resonance (NMR) spectroscopy for structural and dynamic characterization of encapsulated proteins.
- Systematically varying the internal volume of reverse micelles to probe protein folding behavior.
Main Results:
- Demonstrated that confinement within reverse micelles can effectively force-fold metastable proteins.
- Successfully characterized the structure of encapsulated proteins using modern NMR spectroscopy methods.
- Showcased the ability to study the ensemble of unfolded states by adjusting micelle size.
Conclusions:
- Protein encapsulation in reverse micelles offers a powerful strategy to overcome challenges posed by protein unfolding in vitro.
- This approach significantly enhances the utility of NMR spectroscopy for structural proteomics, enabling the study of a broader range of proteins.
- The method provides a unique tool for investigating the fundamental properties and conformational landscapes of unfolded protein states.
Related Concept Videos
01:13Protein Organization
Overview
01:22Protein Folding
Overview
02:15Protein and Protein Structure
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme can...
A protein's shape is critical to its function. For example, an enzyme can...
01:22Protein Folding
Overview
01:24Protein Organization
Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together.
The primary structure of a protein is its amino acid sequence.
The primary structure of a protein is its amino acid sequence.
01:25Protein Folding
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...