Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Molecular Chaperones and Protein Folding03:00

Molecular Chaperones and Protein Folding

The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
Molecular Chaperones and Protein Folding03:00

Molecular Chaperones and Protein Folding

The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
Cooperative Allosteric Transitions01:58

Cooperative Allosteric Transitions

Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Cooperative Allosteric Transitions01:58

Cooperative Allosteric Transitions

Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Cooperative Allosteric Transitions01:58

Cooperative Allosteric Transitions

Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Allosteric Proteins-ATCase01:19

Allosteric Proteins-ATCase

Binding sites linkages can regulate a protein's function.  For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to  N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Polyphosphate modulates the stress-responsive formation of functional RNA-protein condensates in bacteria and mammalian cells.

PLoS biology·2026
Same author

Microprotein Regulates G-quadruplex Driven RNA Aggregation.

bioRxiv : the preprint server for biology·2026
Same author

Advanced Extractables and Leachables Assessment of Microcarriers Used for Adherent Cell Cultures.

Biotechnology journal·2026
Same author

Checking in on proteostasis.

Nature structural & molecular biology·2026
Same author

Visualization of liquid-liquid phase transitions using a tiny G-quadruplex binding protein.

Nature communications·2025
Same author

Identification of host genetic factors modulating β-lactam resistance in <i>Escherichia coli</i> harbouring plasmid-borne β-lactamase through transposon-sequencing.

Emerging microbes & infections·2025

Related Experiment Video

Updated: Jun 24, 2026

Defining Hsp33's Redox-regulated Chaperone Activity and Mapping Conformational Changes on Hsp33 Using Hydrogen-deuterium Exchange Mass Spectrometry
10:24

Defining Hsp33's Redox-regulated Chaperone Activity and Mapping Conformational Changes on Hsp33 Using Hydrogen-deuterium Exchange Mass Spectrometry

Published on: June 7, 2018

Structural plasticity of an acid-activated chaperone allows promiscuous substrate binding.

Timothy L Tapley1, Jan L Körner, Madhuri T Barge

  • 1Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.

Proceedings of the National Academy of Sciences of the United States of America
|March 27, 2009
PubMed
Summary

Heat shock protein HdeA prevents protein aggregation at low pH. This small, energy-independent chaperone rapidly unfolds and changes shape to bind various substrates effectively.

More Related Videos

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo
08:32

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

Published on: October 23, 2016

The Development and Application of Biophysical Assays for Evaluating Ternary Complex Formation Induced by Proteolysis Targeting Chimeras (PROTACS)
07:22

The Development and Application of Biophysical Assays for Evaluating Ternary Complex Formation Induced by Proteolysis Targeting Chimeras (PROTACS)

Published on: January 12, 2024

Related Experiment Videos

Last Updated: Jun 24, 2026

Defining Hsp33's Redox-regulated Chaperone Activity and Mapping Conformational Changes on Hsp33 Using Hydrogen-deuterium Exchange Mass Spectrometry
10:24

Defining Hsp33's Redox-regulated Chaperone Activity and Mapping Conformational Changes on Hsp33 Using Hydrogen-deuterium Exchange Mass Spectrometry

Published on: June 7, 2018

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo
08:32

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

Published on: October 23, 2016

The Development and Application of Biophysical Assays for Evaluating Ternary Complex Formation Induced by Proteolysis Targeting Chimeras (PROTACS)
07:22

The Development and Application of Biophysical Assays for Evaluating Ternary Complex Formation Induced by Proteolysis Targeting Chimeras (PROTACS)

Published on: January 12, 2024

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Protein Folding

Background:

  • HdeA is a small molecular chaperone (9.7 kDa) that prevents acid-induced protein aggregation.
  • Unlike typical chaperones, HdeA functions as a disordered monomer at low pH without ATP.
  • HdeA undergoes an acid-induced dimer to monomer transition for activation.

Purpose of the Study:

  • To investigate the conformational changes of HdeA during acid-induced activation and substrate binding.
  • To understand the mechanism by which HdeA binds substrates in a small, energy-independent manner.

Main Methods:

  • Studied conformational changes using intramolecular Förster Resonance Energy Transfer (FRET).
  • Analyzed the kinetics of acid-induced unfolding and monomerization.
  • Investigated the role of the dimer interface in substrate binding.

Main Results:

  • HdeA activation (unfolding and monomerization) occurs rapidly (k >3.5 s(-1)) upon exposure to low pH.
  • The hydrophobic dimer interface is exposed upon activation and is critical for substrate binding.
  • Active HdeA adopts diverse conformations, enabling recognition and high-affinity binding of various substrate proteins.

Conclusions:

  • HdeA's rapid, pH-regulated activation allows it to function as an efficient, small, and energy-independent chaperone.
  • The chaperone's ability to adopt different conformations is key to its broad substrate specificity.
  • HdeA provides a model for understanding minimalist chaperone mechanisms in cellular stress responses.