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

Sulfur Assimilation01:20

Sulfur Assimilation

456
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
456
Amino Acid Catabolism01:18

Amino Acid Catabolism

1.5K
Microorganisms rely on proteins as an essential carbon and energy source, particularly in environments with limited polysaccharides or lipids. However, proteins are too large to cross the plasma membrane unaided, necessitating enzymatic degradation. Microbes secrete extracellular proteases and peptidases that hydrolyze proteins into peptides, which can then be transported across the membrane. Once inside the cell, intracellular proteases degrade these peptides into free amino acids, which...
1.5K
Protein Modifications in the RER01:26

Protein Modifications in the RER

7.3K
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
7.3K
Phase II Reactions: Sulfation and Conjugation with α-Amino Acids01:19

Phase II Reactions: Sulfation and Conjugation with α-Amino Acids

1.1K
Sulfation and α-amino acid conjugation are two critical biotransformation reactions in drug metabolism. Sulfation, a phase II biotransformation reaction, involves adding a polar sulfate group to a drug, enhancing its water solubility and promoting excretion. This process can either co-occur with or occur independently of glucuronidation. Nonmicrosomal sulfotransferase enzymes catalyze the process. The reaction involves 3'-phosphoadenosine-5'-phosphosulfate or PAPS coenzyme...
1.1K
Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

9.9K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
9.9K
Preparation and Reactions of Thiols02:33

Preparation and Reactions of Thiols

7.8K
Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
7.8K

You might also read

Related Articles

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

Sort by
Same author

Determinants of substrate specificity in D-3-phosphoglycerate dehydrogenase. Conversion of the M. tuberculosis enzyme from one that does not use α-ketoglutarate as a substrate to one that does.

Archives of biochemistry and biophysics·2019
Same author

D-3-Phosphoglycerate Dehydrogenase.

Frontiers in molecular biosciences·2019
Same author

The many faces of partial inhibition: Revealing imposters with graphical analysis.

Archives of biochemistry and biophysics·2018
Same author

Elucidation of a Self-Sustaining Cycle in Escherichia coli l-Serine Biosynthesis That Results in the Conservation of the Coenzyme, NAD<sup/>.

Biochemistry·2018
Same author

Regulatory Mechanism of Mycobacterium tuberculosis Phosphoserine Phosphatase SerB2.

Biochemistry·2017
Same author

Mutagenic and chemical analyses provide new insight into enzyme activation and mechanism of the type 2 iron-sulfur l-serine dehydratase from Legionella pneumophila.

Archives of biochemistry and biophysics·2016

Related Experiment Video

Updated: Mar 8, 2026

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
11:25

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Published on: October 4, 2017

7.2K

Modification of Cysteine.

Gregory A Grant1

  • 1Washington University School of Medicine, Department of Medicine and Department of Developmental Biology, St. Louis, Missouri.

Current Protocols in Protein Science
|February 3, 2017
PubMed
Summary
This summary is machine-generated.

This study details various methods for modifying cysteine residues in proteins and peptides, including alkylation, reversible modification, and oxidation. These techniques are crucial for protein analysis and characterization, offering solutions for diverse experimental conditions.

Keywords:
TCEPalkylationcysteinecysteine modificationdisulfidedithiothreitol

More Related Videos

Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation
07:16

Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation

Published on: June 21, 2021

2.3K
Author Spotlight: Functional Site-Directed Fluorometry in Native Cells to Study Skeletal Muscle Excitability
12:26

Author Spotlight: Functional Site-Directed Fluorometry in Native Cells to Study Skeletal Muscle Excitability

Published on: June 2, 2023

1.5K

Related Experiment Videos

Last Updated: Mar 8, 2026

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
11:25

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Published on: October 4, 2017

7.2K
Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation
07:16

Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation

Published on: June 21, 2021

2.3K
Author Spotlight: Functional Site-Directed Fluorometry in Native Cells to Study Skeletal Muscle Excitability
12:26

Author Spotlight: Functional Site-Directed Fluorometry in Native Cells to Study Skeletal Muscle Excitability

Published on: June 2, 2023

1.5K

Area of Science:

  • Biochemistry
  • Protein Chemistry
  • Analytical Chemistry

Background:

  • Cysteine residues are critical for protein structure and function.
  • Modifying cysteine residues is essential for various analytical techniques.
  • Existing methods may have limitations regarding sample amount or prior knowledge of protein composition.

Purpose of the Study:

  • To provide a comprehensive overview of methods for modifying cysteine residues in proteins and peptides.
  • To present protocols applicable to proteins of known and unknown size and composition.
  • To describe techniques suitable for limited sample amounts and specific analytical applications.

Main Methods:

  • Alkylation using haloacyl reagents or N-ethylmaleimide (NEM).
  • Introduction of amino groups via bromopropylamine and N-(iodoethyl)-trifluoroacetamide.
  • Alkylation with 4-vinylpyridine and acrylamide for sequence analysis, including membrane-bound proteins.
  • Reversible modification via sulfitolysis.
  • Oxidation with performic acid for amino acid analysis.
  • Gentle oxidation to disulfides.
  • Support protocols for reagent preparation and sample handling.

Main Results:

  • A range of cysteine modification protocols are described, catering to different experimental needs.
  • Methods are provided for both small and large scale protein modifications.
  • Specific protocols are highlighted for applications in protein sequencing and amino acid analysis.
  • Supportive techniques for sample preparation and analysis are included.

Conclusions:

  • The described methods offer versatile tools for the targeted modification of cysteine residues.
  • These protocols facilitate subsequent protein analysis, including sequencing and compositional analysis.
  • The unit provides a valuable resource for researchers working with protein and peptide modifications.