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

Radical Chain-Growth Polymerization: Chain Branching01:17

Radical Chain-Growth Polymerization: Chain Branching

2.7K
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
2.7K
Stability of Substituted Cyclohexanes02:30

Stability of Substituted Cyclohexanes

17.7K
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
17.7K
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry01:29

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

6.7K
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
6.7K
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)00:53

Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)

2.3K
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
2.3K
Directing Effect of Substituents: meta-Directing Groups01:09

Directing Effect of Substituents: meta-Directing Groups

6.6K
Substituents on the benzene ring that direct an incoming electrophile to undergo substitution at the meta position are called meta directors. All meta directors either have a positive charge on the atom directly bonded to the ring or a partial positive charge. These groups function by withdrawing electrons from the ring through inductive and resonance effects. Consider the carbocation intermediates formed upon the addition of an electrophile on nitrobenzene at the...
6.6K
Nucleophilic Aromatic Substitution: Elimination–Addition01:11

Nucleophilic Aromatic Substitution: Elimination–Addition

5.8K
Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is...
5.8K

You might also read

Related Articles

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

Sort by
Same author

Allosteric disordering of eIF2B regulates the integrated stress response.

Nature chemical biology·2026
Same author

Breaking the membrane heredity paradox through de novo protocell formation.

Nature communications·2026
Same author

The evolving role of structural biology in pharma: integration of X-ray crystallography, cryo-electron microscopy and beyond.

Acta crystallographica. Section D, Structural biology·2026
Same author

Toward Fully Renewable Rigid Polyurethane Foams with Aliphatic Diisocyanates.

Biomacromolecules·2026
Same author

A Hidden Binding Pocket in the β- ketoacyl-ACP Synthase FabB.

bioRxiv : the preprint server for biology·2026
Same author

Determination of THC and THC-COOH in Dried Capillary Blood Spots and Comparison to Venous Blood of Recreational Cannabis Consumers in a Pilot Study.

Drug testing and analysis·2026

Related Experiment Video

Updated: Apr 20, 2026

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028
09:08

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

Published on: January 13, 2017

18.0K

Modeling linear and cyclic PKS intermediates through atom replacement.

Gaurav Shakya1, Heriberto Rivera, D John Lee

  • 1Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences, University of California , Irvine, California 92697, United States.

Journal of the American Chemical Society
|November 20, 2014
PubMed
Summary
This summary is machine-generated.

Researchers developed an atom replacement method to create polyketide synthase (PKS) mimics. These mimics reveal how PKS enzymes bind substrates during chain elongation and cyclization, clarifying PKS mechanism and processivity.

More Related Videos

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center
07:11

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center

Published on: September 28, 2022

3.3K
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
09:42

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes

Published on: January 16, 2016

9.5K

Related Experiment Videos

Last Updated: Apr 20, 2026

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028
09:08

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

Published on: January 13, 2017

18.0K
Constructing Cyclic Peptides Using an On-Tether Sulfonium Center
07:11

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center

Published on: September 28, 2022

3.3K
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
09:42

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes

Published on: January 16, 2016

9.5K

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Organic Chemistry

Background:

  • Polyketide synthases (PKSs) are crucial for producing diverse natural products.
  • Understanding PKS mechanisms is hindered by the instability of transient intermediates.
  • Current methods struggle to access these intermediates for detailed study.

Purpose of the Study:

  • To develop a novel strategy for preparing stable polyketide intermediates.
  • To investigate substrate binding and PKS processivity using these intermediates.
  • To elucidate the role of the acyl carrier protein (ACP) in PKS function.

Main Methods:

  • Atom replacement strategy to synthesize polyketone surrogates (mimetics).
  • Utilizing actinorhodin ACP (actACP) to study substrate association.
  • Protein Nuclear Magnetic Resonance (NMR) spectroscopy to visualize protein-substrate interactions.
  • Evaluation of binding kinetics for stabilized cyclic intermediates.

Main Results:

  • Tetraketide substrates do not bind actACP, while longer substrates (heptaketide, octaketide) bind strongly.
  • Stabilized cyclic mimics show longer residence times on actACP compared to shorter analogs.
  • ACP-substrate association occurs both before and after ketoreductase action.

Conclusions:

  • Atom replacement provides valuable tools for studying PKS mechanisms.
  • ACP plays a critical role in PKS timing and processivity.
  • The developed mimetics are applicable to a broad range of PKS systems.