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

Electrospray Ionization (ESI) Mass Spectrometry01:12

Electrospray Ionization (ESI) Mass Spectrometry

1.8K
Higher molecular weight biomolecules are nonvolatile compounds that may decompose before ionizing or vaporizing during mass analysis with conventional electron impact ionization methods. Accordingly, electrospray ionization (ESI) is the favored method for vaporizing and ionizing biomolecules as it circumvents rapid fragmentation and enables the recording of mass signals for the entire biomolecule.
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
1.8K
Molecules with Multiple Chiral Centers02:25

Molecules with Multiple Chiral Centers

14.5K
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
14.5K

You might also read

Related Articles

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

Sort by
Same author

Native mass spectrometry reveals DltA catalysis, DltC loading, and inhibition in the d-alanylation pathway.

RSC advances·2026
Same author

Utilization of Tandem-Column UHPLC for High-Throughput Peptide Mapping of Therapeutic Proteins.

Analytical chemistry·2026
Same author

Quantitation of Diastereomer Content in PS-Modified Synthetic Oligonucleotides using cIMS-MS.

Analytical chemistry·2026
Same author

Temperature and lipid composition differentially regulate KRAS assemblies on membranes.

Chemical communications (Cambridge, England)·2026
Same author

Time-Resolved Native Mass Spectrometry for Direct Measurement of Biomolecular Kinetics.

Journal of the American Chemical Society·2026
Same author

Peptidomimetic α,β-Unsaturated Ethyl Esters Are Irreversible Inactivators of Human Cathepsin L and Are Potent Inhibitors of SARS-CoV-2 in Cellular Models of COVID-19.

Journal of medicinal chemistry·2026

Related Experiment Video

Updated: Dec 10, 2025

Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics
09:18

Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics

Published on: April 17, 2017

10.2K

Evidence for Many Unique Solution Structures for Chymotrypsin Inhibitor 2: A Thermodynamic Perspective Derived from

Shannon A Raab1, Tarick J El-Baba1, Daniel W Woodall1

  • 1Department of Chemistry, Indiana University, 800 Kirkwood Avenue, Bloomington, Indiana 47401, United States.

Journal of the American Chemical Society
|September 1, 2020
PubMed
Summary

Chymotrypsin inhibitor 2 (CI-2) protein folding was studied using variable-temperature electrospray ionization (vT-ESI) coupled with ion mobility spectrometry-mass spectrometry (IMS-MS). This technique revealed over 40 unique CI-2 solution conformations, mapping the free energy folding landscape.

More Related Videos

Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities
11:44

Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities

Published on: October 2, 2018

13.0K
The Determination of Protease Specificity in Mouse Tissue Extracts by MALDI-TOF Mass Spectrometry: Manipulating PH to Cause Specificity Changes
09:47

The Determination of Protease Specificity in Mouse Tissue Extracts by MALDI-TOF Mass Spectrometry: Manipulating PH to Cause Specificity Changes

Published on: May 25, 2018

7.0K

Related Experiment Videos

Last Updated: Dec 10, 2025

Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics
09:18

Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics

Published on: April 17, 2017

10.2K
Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities
11:44

Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities

Published on: October 2, 2018

13.0K
The Determination of Protease Specificity in Mouse Tissue Extracts by MALDI-TOF Mass Spectrometry: Manipulating PH to Cause Specificity Changes
09:47

The Determination of Protease Specificity in Mouse Tissue Extracts by MALDI-TOF Mass Spectrometry: Manipulating PH to Cause Specificity Changes

Published on: May 25, 2018

7.0K

Area of Science:

  • Biophysics
  • Structural Biology
  • Physical Chemistry

Background:

  • Chymotrypsin inhibitor 2 (CI-2) is a well-established model system for studying protein folding.
  • Traditional methods have extensively characterized wild-type (wt) and mutant CI-2 forms.
  • Understanding protein folding landscapes is crucial for deciphering biological processes.

Purpose of the Study:

  • To demonstrate the utility of variable-temperature electrospray ionization (vT-ESI) coupled with ion mobility spectrometry-mass spectrometry (IMS-MS) for mapping protein free energy folding landscapes.
  • To investigate the conformational diversity and thermodynamic properties of CI-2 under varying temperatures.
  • To provide a detailed energy landscape of CI-2 thermal denaturation.

Main Methods:

  • Utilized variable-temperature (vT) electrospray ionization (ESI) combined with ion mobility spectrometry (IMS) and mass spectrometry (MS).
  • Analyzed wild-type (wt) CI-2 and three mutant forms (A16G, K11A, L32A) across approximately 30 different temperatures.
  • Performed thermodynamic analysis to determine changes in heat capacity (ΔCp), free energy (ΔG), enthalpy (ΔH), and entropy (ΔS).

Main Results:

  • Observed independent variations in the abundance of six ESI charge states for wt CI-2 and mutants with increasing temperature, indicating at least six unique solution conformers.
  • Ion mobility analysis revealed additional conformers within each charge state with distinct temperature profiles.
  • A comprehensive model identified 41 unique CI-2 solution conformations, providing detailed energy landscapes and thermodynamic parameters (ΔCp, ΔG, ΔH, ΔS) for each state across temperatures.

Conclusions:

  • vT-ESI-IMS-MS is a powerful technique for mapping complex protein folding landscapes and characterizing diverse solution conformers.
  • The study reveals a significantly more complex conformational ensemble for CI-2 thermal denaturation than the traditional two-state model.
  • Detailed energy landscapes offer insights into Anfinsen's thermodynamic hypothesis and the dynamic balance of protein conformations during thermal denaturation.