Protein Refolding
Protein Refolding - Related Videos
07:18
Intracellular Refolding Assay
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Cited by 9 •
2012
In this protocol a method to measure intracellular protein refolding after heat shock is described. This method can be used to study foldases like molecular chaperones and their co-factors or compounds able to influence their activity. Firefly luciferase activity is used as reporter to measure chaperone refolding activity.
13:52
Coupled Assays for Monitoring Protein Refolding in Saccharomyces cerevisiae
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Cited by 14 •
2013
This article describes the use of a firefly luciferase-GFP fusion protein to investigate in vivo protein folding in Saccharomyces cerevisiae. Using this reagent, refolding of a model heat-denatured protein can be monitored simultaneously by fluorescence microscopy and an enzymatic assay to probe the roles of proteostasis network components in protein quality control.
09:43
Purification and Refolding to Amyloid Fibrils of (His)6-tagged Recombinant Shadoo Protein Expressed as Inclusion Bodies in E. coli
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Cited by 3 •
2015
A two-step chromatographic method is described for the purification of recombinant Shadoo protein expressed as inclusion bodies in Escherichia coli, as well as a protocol to fibrillate purified Shadoo into amyloid structures.
02:18
Intrinsically Disordered Proteins
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2020
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...
08:38
Protein Membrane Overlay Assay: A Protocol to Test Interaction Between Soluble and Insoluble Proteins in vitro
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Cited by 6 •
2011
Testing protein-protein interaction is indispensable for dissection of protein functionality. Here, we introduce an in vitro protein-protein binding assay to probe a membrane-immobilized protein with a soluble protein. This assay provides a reliable method to test interaction between an insoluble protein and a protein in solution.
FAQs
Protein refolding depends strongly on how denaturing conditions are removed. High urea concentrations or extreme pH disrupt the interactions that maintain a protein’s structure; reducing those conditions permits the protein to reorganize. A controlled transition matters because the goal is not simply to eliminate the denaturant, but to create conditions in which a functional three-dimensional structure can return.
During refolding, noncovalent interactions help the protein regain its three-dimensional arrangement, while disulfide bonds can reform as conditions become suitable. These interactions are central because functional activity depends on the resulting structure, not merely on the protein’s amino acid sequence being present. Their reestablishment connects molecular recovery with restoration of biological function.
Aggregation competes with the formation of the desired individual protein structure. As denaturing conditions are removed, proteins may associate with one another instead of completing refolding, reducing the amount of functional product recovered. Molecular chaperones or carefully controlled dilution can reduce this problem, making the transition more favorable for obtaining active protein.
Protein refolding can be used to examine how sequence determines structure. If a denatured protein regains its characteristic three-dimensional form, the result provides a way to study the structural information encoded by its sequence. This relationship also helps frame misfolding research, where the protein does not reach the functional arrangement needed for normal activity.
A typical workflow begins with protein exposed to a denaturing condition, such as high urea or extreme pH. Researchers then remove or reduce that condition, often using carefully controlled dilution, while allowing structural interactions and disulfide bonds to reform. Molecular chaperones may be included to limit aggregation. The intended outcome is recovery of functional protein.
Researchers use protein refolding to recover active proteins produced in microbial expression systems. This application is important when the expressed protein must be returned to a functional three-dimensional structure before it can provide useful biological activity. Improving the refolding step can therefore support production of enzymes, therapeutic proteins, and other biologically valuable molecules.
Protein refolding provides an experimental framework for comparing recovery of a functional structure with formation of a misfolded state. In biology, that comparison helps researchers investigate diseases linked to protein misfolding. The process also connects molecular structure with biological function, since failure to regain the appropriate three-dimensional arrangement can prevent the protein from operating normally.