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

Protein Folding01:22

Protein Folding

129.8K
Overview
129.8K
Protein Folding01:25

Protein Folding

12.1K
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...
12.1K
Protein Folding01:22

Protein Folding

36.1K
36.1K
Protein and Protein Structure02:15

Protein and Protein Structure

91.3K
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...
91.3K
Protein Organization01:13

Protein Organization

160.7K
Overview
160.7K
Protein Organization01:24

Protein Organization

9.9K
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....
9.9K

You might also read

Related Articles

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

Sort by
Same author

Sugar-protein interactions control protein-complex stability in crowded Ficoll and dextran solutions.

Protein science : a publication of the Protein Society·2025
Same author

Using NMR-detected hydrogen-deuterium exchange to quantify protein stability in cosolutes, under crowded conditions <i>in vitro</i> and in cells.

Magnetic resonance letters·2025
Same author

Effects of Lyophilization, Vacuum Drying, and Microglassification on Two Model Proteins Assessed at the Residue Level Using Liquid Observed Vapor Exchange Nuclear Magnetic Resonance Spectroscopy (LOVE NMR).

Molecular pharmaceutics·2025
Same author

Crowding-induced stabilization and destabilization in a single protein.

Protein science : a publication of the Protein Society·2025
Same author

Crowding beyond excluded volume: A tale of two dimers.

Protein science : a publication of the Protein Society·2025
Same author

Understanding dry proteins and their protection with solid-state hydrogen-deuterium exchange.

Protein science : a publication of the Protein Society·2025
Same journal

Switching Site Selectivity in Alkoxyamine Hydration: From Lone-Pair Direction to Solvent Network Dominance.

Journal of the American Chemical Society·2026
Same journal

A Topotactic Leap: 2D Layers to 3D Large-Pore Zeolite.

Journal of the American Chemical Society·2026
Same journal

Enhanced Hydrogen Evolution over Single-Atom Catalysts via Electrostatic Polarization in Contact-electro-catalysis.

Journal of the American Chemical Society·2026
Same journal

Tumor Acidity-Activatable Ionizable Lipid Nanoparticles for Selective Oncolytic Therapy.

Journal of the American Chemical Society·2026
Same journal

Alternating Magnetic Field Promotes Ammonia Cracking by Disrupting the Sabatier Limitation of Ruthenium Catalytic Species.

Journal of the American Chemical Society·2026
Same journal

Bulk Ferromagnetic Icosahedral Quasicrystals without Rapid Quenching.

Journal of the American Chemical Society·2026
See all related articles

Related Experiment Video

Updated: Mar 14, 2026

A Protocol for Computer-Based Protein Structure and Function Prediction
16:41

A Protocol for Computer-Based Protein Structure and Function Prediction

Published on: November 3, 2011

70.0K

Electrostatic Contributions to Protein Quinary Structure.

Rachel D Cohen1, Gary J Pielak1

  • 1Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.

Journal of the American Chemical Society
|September 28, 2016
PubMed
Summary
This summary is machine-generated.

Researchers quantified quinary protein structure in living cells, revealing that pH-dependent electrostatic interactions influence protein stability and organization within the crowded cellular environment.

More Related Videos

Determination of the Gas-phase Acidities of Oligopeptides
11:00

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

11.7K
Protein WISDOM: A Workbench for In silico De novo Design of BioMolecules
10:58

Protein WISDOM: A Workbench for In silico De novo Design of BioMolecules

Published on: July 25, 2013

17.7K

Related Experiment Videos

Last Updated: Mar 14, 2026

A Protocol for Computer-Based Protein Structure and Function Prediction
16:41

A Protocol for Computer-Based Protein Structure and Function Prediction

Published on: November 3, 2011

70.0K
Determination of the Gas-phase Acidities of Oligopeptides
11:00

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

11.7K
Protein WISDOM: A Workbench for In silico De novo Design of BioMolecules
10:58

Protein WISDOM: A Workbench for In silico De novo Design of BioMolecules

Published on: July 25, 2013

17.7K

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Background:

  • Protein structure is typically described by four levels: primary, secondary, tertiary, and quaternary.
  • Quinary structure, representing transient macromolecular interactions in the crowded cell interior, remains poorly defined.
  • Characterizing quinary structure necessitates measuring thermodynamic parameters within living cells.

Purpose of the Study:

  • To define the fifth level of protein structure (quinary structure) by quantifying its characteristics in vivo.
  • To investigate the pH-dependence of quinary interactions within living Escherichia coli cells.
  • To elucidate the role of electrostatic interactions in cellular protein organization.

Main Methods:

  • Utilized the B1 domain of protein G (GB1) as a model system.
  • Employed NMR-detected amide proton exchange to quantify protein unfolding free energy in living cells.
  • Buffered the intracellular environment of E. coli to control pH conditions.

Main Results:

  • The unfolding free energy of GB1 in cells at neutral pH is comparable to that in buffered solutions.
  • Decreasing cellular pH leads to destabilization of GB1 within the cell compared to buffer alone.
  • Electrostatic interactions between E. coli proteins and GB1 were identified as a key contributor to quinary structure.

Conclusions:

  • Quinary structure is quantifiable in living cells using thermodynamic measurements.
  • Cellular pH significantly impacts quinary interactions and protein stability.
  • Electrostatic forces play a crucial role in establishing and maintaining quinary protein organization.