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

Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Crystal Field Theory - Octahedral Complexes02:58

Crystal Field Theory - Octahedral Complexes

Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Valence Bond Theory02:42

Valence Bond Theory

Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Complexometric Titration: Ligands00:43

Complexometric Titration: Ligands

Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
EDTA: Chemistry and Properties01:22

EDTA: Chemistry and Properties

Polydentate ligands are most widely used in complexometric titrations because they form more stable complexes with the metal ions than mono- or bidentate ligands due to the chelate effect. Examples of polydentate ligands are ethylenediaminetetraacetic acid (EDTA), crown ethers, and cryptands. The most important feature of optimal polydentate ligands is the ability to form 1:1 complexes in a single-step process. Amino carboxylic acid derivatives are frequently used as complexing agents. EDTA is...
Complexation Equilibria: The Chelate Effect01:19

Complexation Equilibria: The Chelate Effect

In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...

You might also read

Related Articles

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

Sort by
Same author

Resolving Conformational Preferences of Monosaccharides from <sup>1</sup>H and <sup>13</sup>C NMR Chemical Shifts Using an Integrated MD and QM Approach.

Journal of chemical information and modeling·2026
Same author

A novel quinazolinone insulin receptor inhibitor and its synergy with an EGFR inhibitor in glucose-driven glioblastoma.

Molecular oncology·2026
Same author

Effects of interfacial hydrogen bonding and electrostatic interactions on the adsorption and foaming properties in saponin mixtures.

Journal of colloid and interface science·2026
Same author

Effect of glycosidic torsional energetics on the conformational properties of polysaccharide chains: a Monte Carlo study.

Carbohydrate research·2026
Same author

Conformational Properties of Single-Chain Polyuronates: A Comparative Molecular Simulation Study of Polyglucuronates, Polygalacturonates, and Alginates.

The journal of physical chemistry. B·2026
Same author

New Derivatives of 2-(Cyclohexylamino)thiazol-4(5<i>H</i>)-one as Strong Inhibitors of 11β-Hydroxysteroid Dehydrogenase Type 1: Synthesis, Antiproliferative and Redox-Modulating Activity.

International journal of molecular sciences·2025

Related Experiment Video

Updated: May 7, 2026

Modeling Ligands into Maps Derived from Electron Cryomicroscopy
09:30

Modeling Ligands into Maps Derived from Electron Cryomicroscopy

Published on: July 19, 2024

Calcium-α-L-guluronate complexes: Ca2+ binding modes from DFT-MD simulations.

Wojciech Plazinski1, Mateusz Drach

  • 1Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences , ul. Niezapominajek 8, 30-239 Cracow, Poland.

The Journal of Physical Chemistry. B
|September 18, 2013
PubMed
Summary

This study used advanced molecular dynamics to explore calcium ion binding to alginate chains. Findings clarify calcium binding modes and validate structural models, enhancing our understanding of these interactions.

Related Experiment Videos

Last Updated: May 7, 2026

Modeling Ligands into Maps Derived from Electron Cryomicroscopy
09:30

Modeling Ligands into Maps Derived from Electron Cryomicroscopy

Published on: July 19, 2024

Area of Science:

  • Biomolecular Chemistry
  • Computational Chemistry
  • Materials Science

Background:

  • Alginates are polysaccharides with significant applications in biomaterials and drug delivery.
  • Understanding calcium ion interactions with alginates is crucial for optimizing their functional properties.
  • Previous models of calcium alginate structures require further computational validation.

Purpose of the Study:

  • To investigate the binding mechanisms of divalent calcium ions (Ca2+) with α-L-guluronate anions and oligomers.
  • To determine the free energy profiles associated with calcium binding and unbinding.
  • To computationally validate and refine existing models of calcium alginate/guluronate structures.

Main Methods:

  • Employed a 'hybrid' molecular dynamics technique combining different levels of theory (Density Functional Theory Molecular Dynamics - DFT-MD).
  • Simulations focused on calculating free energy profiles to elucidate calcium binding modes.
  • Analyzed coordination environments of calcium ions, exclusively involving carboxyl oxygen atoms and water molecules.

Main Results:

  • Determined the denticity of calcium binding to alginate chains.
  • Estimated free energy profiles for calcium binding and unbinding processes.
  • Provided positive verification for a modified egg-box model of calcium alginate/guluronate structure.
  • Observed that Ca2+ induced polarization of carboxyl groups increases the free energy barrier for binding compared to classical force fields.

Conclusions:

  • The study clarifies calcium binding modes to alginates at a molecular level.
  • Findings support and refine existing structural models for calcium alginate complexes.
  • The enhanced free energy barrier due to Ca2+ polarization highlights limitations of classical force fields for these systems.