Related Experiment Video
Updated: May 24, 2026
15:33
Microwave-assisted Functionalization of Poly(ethylene glycol) and On-resin Peptides for Use in Chain Polymerizations and Hydrogel Formation
Published on: October 29, 2013
Structure of sodiated polyglycines
O Petru Balaj1, David Semrouni, Vincent Steinmetz
1Laboratoire des Mécanismes Réactionnels, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|March 6, 2012
Summary
Sodiated polyglycines reveal complex folding structures around sodium ions. A key structural transition occurs around G(7)-Na(+), influencing peptide interactions and coordination geometry.
Area of Science:
- Chemical Physics
- Spectroscopy
- Computational Chemistry
Background:
- Peptide conformation is crucial for biological function.
- Understanding metal-ion interactions with peptides provides insights into biomolecular recognition.
Purpose of the Study:
- Investigate the intrinsic folding of peptides around sodium ions.
- Determine structural details of sodiated polyglycines using spectroscopy and theory.
Main Methods:
- Infrared multiple photon dissociation (IRMPD) spectroscopy on sodiated polyglycines (G(n)-Na+, n=2-8).
- Combination of classical and quantum theoretical computational methods.
- H/D exchange experiments for structural confirmation.
Main Results:
- Stable structures for smaller peptides (up to G(6)-Na+) feature maximal metal-peptide interactions with C=O groups bound to sodium.
- Larger peptides exhibit increased flexibility, leading to complex folding with γ or β turns.
- A structural transition occurs between G(6)-Na+ and G(7)-Na+, with sodium coordination becoming three-dimensional for G(7)-Na+ and larger peptides.
Conclusions:
- Peptide folding around sodium ions is complex and size-dependent.
- A distinct structural transition influences sodium coordination and peptide structuration.
- Experimental and computational data show good agreement for the charge solvation isomer.
More Related Videos
11:32Characteristics of Precipitation-formed Polyethylene Glycol Microgels Are Controlled by Molecular Weight of Reactants
Published on: December 23, 2013
06:56Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) Mass Spectrometry
Published on: June 10, 2018
Related Concept Videos
01:05Proteoglycans
Glycans, a class of complex heterogeneous molecules, can be covalently attached to proteins to form glycosylated proteins that regulate various physiological and pathological processes. Glycosylated proteins or glycoproteins comprise N-linked and O-linked oligosaccharides. O-glycosylation is the most common type of protein glycosylation. Here, glycans attach to the oxygen atom of the hydroxyl groups of Serine or Threonine residues. O-linked glycosylation occurs later in protein processing,...
01:23Glycosaminoglycans
Glycosaminoglycans (GAGs), also known as mucopolysaccharides, are long and linear polymers comprising of specific repeating disaccharides - the amino sugar that can be N-acetylglucosamine or N-acetylgalactosamine, and a uronic acid that is usually glucuronic acid or iduronic acid.
GAGS are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Due to their polar nature they attract water, and serve as excellent lubricants or shock absorbers in an animal body.
Hyaluronic...
GAGS are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Due to their polar nature they attract water, and serve as excellent lubricants or shock absorbers in an animal body.
Hyaluronic...
01:25Protein Glycosylation
Glycosylation, the most common post-translational modification for proteins, serves diverse functions. Adding sugars to proteins makes the proteins more resistant to proteolytic digestion. Glycosylated proteins can act as markers and receptors to promote cell-cell adhesion. Additionally, they have many essential quality control functions in the cell, such as correct protein folding and facilitating transport of misfolded proteins to the cytosol, which can be degraded.
Glycosylation occurs in...
Glycosylation occurs in...
01:24Oligosaccharide Assembly
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
00:57Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
03:25Chemistry of Carbohydrates
Carbohydrates are an essential part of the diet in humans and animals. Grains, fruits, and vegetables are natural sources of carbohydrates that provide energy to the body, particularly through glucose, a simple sugar that is a component of starch and an ingredient in many staple foods. The stoichiometric formula (CH2O)n, where n is the number of carbons in the molecule represents carbohydrates. In other words, the ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules. This...