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

Conservative Site-specific Recombination and Phase Variation02:53

Conservative Site-specific Recombination and Phase Variation

6.0K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
6.0K
Protein Modifications in the RER01:26

Protein Modifications in the RER

5.2K
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...
5.2K
Protein Complexes with Interchangeable Parts01:57

Protein Complexes with Interchangeable Parts

2.5K
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
2.5K
Peptide Identification Using Tandem Mass Spectrometry01:33

Peptide Identification Using Tandem Mass Spectrometry

6.5K
Tandem mass spectrometry, also known as MS/MS or MS2, is an analytical technique that employs two mass analyzers. Essentially it is a series of mass spectrometers that helps isolate a particular biomolecule and then helps study its chemical properties.
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...
6.5K

You might also read

Related Articles

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

Sort by
Same author

Deaminative Ring Contraction for the Modular Synthesis of Pyrido[<i>n</i>]helicenes.

Organic letters·2026
Same author

Leader-Independent C‑Terminal Modification by a Radical <i>S</i>‑Adenosyl‑l‑methionine Maturase Enables Macrocyclic GLP-1-Like Peptides.

ACS bio & med chem Au·2025
Same author

Diverse thioether macrocyclized peptides through a radical SAM maturase.

Proceedings of the National Academy of Sciences of the United States of America·2025
Same author

Pursuing theranostics: a multimodal architecture approach.

Sensors & diagnostics·2024
Same author

Capturing the Binuclear Copper State of Peptidylglycine Monooxygenase Using a Peptidyl-Homocysteine Lure.

Journal of the American Chemical Society·2024
Same author

Lasso Peptides: Exploring the Folding Landscape of Nature's Smallest Interlocked Motifs.

Journal of the American Chemical Society·2024

Related Experiment Video

Updated: Jul 7, 2025

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
11:33

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking

Published on: December 17, 2013

6.2K

A Promiscuous rSAM Enzyme Enables Diverse Peptide Cross-linking.

Karsten A S Eastman1, Marcus C Mifflin1, Paul F Oblad1

  • 1Department of Chemistry, University of Utah, 315 S. 1400 E, Salt Lake City, Utah 84112, United States.

ACS Bio & Med Chem Au
|December 25, 2023
PubMed
Summary
This summary is machine-generated.

PapB, an enzyme forming thioether cross-links in RiPPs, shows remarkable substrate flexibility. It efficiently modifies peptides with altered residues, revealing insights into its active site and potential for peptide therapeutics.

More Related Videos

Combining Chemical Cross-linking and Mass Spectrometry of Intact Protein Complexes to Study the Architecture of Multi-subunit Protein Assemblies
10:01

Combining Chemical Cross-linking and Mass Spectrometry of Intact Protein Complexes to Study the Architecture of Multi-subunit Protein Assemblies

Published on: November 28, 2017

19.7K
Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids
11:56

Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids

Published on: May 4, 2018

12.5K

Related Experiment Videos

Last Updated: Jul 7, 2025

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
11:33

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking

Published on: December 17, 2013

6.2K
Combining Chemical Cross-linking and Mass Spectrometry of Intact Protein Complexes to Study the Architecture of Multi-subunit Protein Assemblies
10:01

Combining Chemical Cross-linking and Mass Spectrometry of Intact Protein Complexes to Study the Architecture of Multi-subunit Protein Assemblies

Published on: November 28, 2017

19.7K
Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids
11:56

Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids

Published on: May 4, 2018

12.5K

Area of Science:

  • Biochemistry
  • Enzymology
  • Natural Products Chemistry

Background:

  • Ribosomally produced and post-translationally modified polypeptides (RiPPs) are a diverse class of natural products.
  • PapB, a radical S-adenosyl-l-methionine (rSAM) enzyme, catalyzes thioether cross-linking in the PapA RiPP between cysteine and aspartate residues.

Purpose of the Study:

  • To investigate the substrate tolerance and specificity of the PapB enzyme.
  • To elucidate the mechanism of thioether cross-link formation by PapB.
  • To explore the potential of PapB as a tool for peptide therapeutics development.

Main Methods:

  • Enzymatic assays using modified peptide substrates.
  • Synthesis of diastereomeric peptide substrates with altered side chains and configurations.
  • Analysis of reaction products and enzyme kinetics.

Main Results:

  • PapB exhibits high tolerance for variations in thiol- and carboxylate-containing residues, including side chain lengthening and replacement with tetrazole.
  • The enzyme efficiently cross-links peptides with bulky or charged residues, including unnatural D-amino acids.
  • PapB demonstrates diastereospecificity in hydrogen atom abstraction and can promote deoxyadenosyl radical addition to dehydrohomoglutamate substrates, indicating product inhibition.

Conclusions:

  • PapB possesses unusual promiscuity, accepting a wide range of peptide substrates.
  • The study provides critical insights into the active site dynamics of PapB.
  • PapB's versatility suggests its potential utility in designing and developing novel peptide therapeutics.