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

Redox Reactions01:24

Redox Reactions

Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
C4 Pathway and CAM01:27

C4 Pathway and CAM

Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative pathways to fix carbon and conserve energy loss due to photorespiration. Photorespiration is the process that occurs when the oxygen concentration is high. Under such conditions, the rubisco enzyme in the Calvin cycle binds O2 instead of CO2, which halts photosynthesis and consumes energy.
C4 Pathway
The C4 pathway is used by plants such as...
The Carbon Cycle01:14

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
Bioremediation00:46

Bioremediation

Bioremediation is the use of prokaryotes, fungi, or plants to remove pollutants from the environment. This process has been used to remove harmful toxins in groundwater as a byproduct of agricultural run-off and also to clean up oil spills.
Precipitation and Co-precipitation01:17

Precipitation and Co-precipitation

Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
Carbon-dioxide Fixation01:28

Carbon-dioxide Fixation

Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...

You might also read

Related Articles

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

Sort by
Same author

Viral capsid delivery of cGAMP enhances STING-dependent antitumor immune response.

bioRxiv : the preprint server for biology·2026
Same author

Amino Acid Variants at the P94 Position in <i>Staphylococcus aureus</i> Class a Sortase Modulate Substrate Binding and Enzyme Activity.

Biochemistry·2026
Same author

Amino acid variants at the P94 position in <i>Staphylococcus aureus</i> class A sortase modulate substrate binding and enzyme activity.

bioRxiv : the preprint server for biology·2026
Same author

Biosynthesis of Minimal C-Phycocyanin Chromophore Assemblies in <i>E. coli</i> Provides a Platform to Dissect Protein-Mediated Tuning of Exciton Transfer.

Journal of the American Chemical Society·2026
Same author

A Putative Interaction between the Transmembrane Domains of <i>Streptococcus pyogenes</i> Sortase A and Its Endogenous Substrate M Protein Revealed by Molecular Dynamics Simulations.

The journal of physical chemistry. B·2025
Same author

Engineered MS2 Virus Capsids for Cellular Display of Peptide Antigens.

ACS chemical biology·2025

Related Experiment Video

Updated: Jul 8, 2026

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
10:57

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Published on: April 10, 2018

Selective tryptophan modification with rhodium carbenoids in aqueous solution.

John M Antos1, Matthew B Francis

  • 1Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA.

Journal of the American Chemical Society
|August 19, 2004
PubMed
Summary

A novel rhodium-catalyzed reaction enables selective modification of tryptophan residues in proteins using vinyl-substituted diazo compounds in aqueous solutions. This method is effective even at low protein concentrations and preserves protein function, such as heme binding in myoglobin.

More Related Videos

Preparation of Biomass-based Mesoporous Carbon with Higher Nitrogen-/Oxygen-chelating Adsorption for Cu(II) Through Microwave Pre-Pyrolysis
10:44

Preparation of Biomass-based Mesoporous Carbon with Higher Nitrogen-/Oxygen-chelating Adsorption for Cu(II) Through Microwave Pre-Pyrolysis

Published on: February 12, 2019

A Synthetic Methodology for Preparing Impregnated and Grafted Amine-Based Silica Composites for Carbon Capture
08:00

A Synthetic Methodology for Preparing Impregnated and Grafted Amine-Based Silica Composites for Carbon Capture

Published on: September 29, 2023

Related Experiment Videos

Last Updated: Jul 8, 2026

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
10:57

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Published on: April 10, 2018

Preparation of Biomass-based Mesoporous Carbon with Higher Nitrogen-/Oxygen-chelating Adsorption for Cu(II) Through Microwave Pre-Pyrolysis
10:44

Preparation of Biomass-based Mesoporous Carbon with Higher Nitrogen-/Oxygen-chelating Adsorption for Cu(II) Through Microwave Pre-Pyrolysis

Published on: February 12, 2019

A Synthetic Methodology for Preparing Impregnated and Grafted Amine-Based Silica Composites for Carbon Capture
08:00

A Synthetic Methodology for Preparing Impregnated and Grafted Amine-Based Silica Composites for Carbon Capture

Published on: September 29, 2023

Area of Science:

  • Organic Chemistry
  • Biochemistry
  • Catalysis

Background:

  • Selective modification of amino acid residues in proteins is crucial for biochemical studies and protein engineering.
  • Tryptophan residues, with their indole side chains, offer unique reactivity but are challenging to modify selectively under aqueous conditions.
  • Existing methods often require harsh conditions or lack specificity, limiting their application in native protein environments.

Purpose of the Study:

  • To develop a new transition metal-catalyzed reaction for the selective modification of tryptophan residues in proteins.
  • To investigate the mechanism and scope of the reaction using small molecules and protein substrates.
  • To confirm the tryptophan selectivity and assess the impact of the modification on protein structure and function.

Main Methods:

  • Activation of vinyl-substituted diazo compounds using Rh2(OAc)4 to generate metallocarbenoid intermediates.
  • Reaction of metallocarbenoids with indole-containing small molecules and protein substrates (myoglobin, subtilisin Carlsberg) in aqueous media.
  • Confirmation of tryptophan modification selectivity using mass spectrometry (MS) analysis of trypsin digest fragments.
  • Assessment of myoglobin's heme-binding capacity post-modification through reconstitution experiments.

Main Results:

  • A new Rh-catalyzed reaction selectively modifies tryptophan residues in aqueous solution, overcoming competing hydrolysis.
  • Both N- and 2-substituted indole products were observed in small-molecule studies.
  • Myoglobin and subtilisin Carlsberg were successfully modified at tryptophan residues, even at low myoglobin concentrations (10 µM).
  • Modification did not impede myoglobin's ability to bind heme.

Conclusions:

  • The developed Rh-catalyzed reaction provides a robust and selective method for tryptophan modification in proteins under aqueous conditions.
  • This methodology is applicable to various protein substrates and preserves essential protein functions.
  • The reaction holds promise for applications in chemical biology, proteomics, and protein engineering.