Related Experiment Video
Updated: Feb 8, 2026
09:57
A Facile and Efficient Approach for the Production of Reversible Disulfide Cross-linked Micelles
Published on: December 23, 2016
9.3K
Ether cross-link formation in the R2-like ligand-binding oxidase
Julia J Griese1,2, Rui M M Branca3, Vivek Srinivas4
1Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden. julia.griese@icm.uu.se.
Summary
R2-like oxidases with manganese/iron cofactors are more efficient at protein cross-linking than iron-only ones. Cofactor reactivity is specific, enabling cross-links with isoleucine but not leucine or alanine.
Area of Science:
- Biochemistry
- Enzymology
- Bioinorganic Chemistry
Background:
- R2-like ligand-binding oxidases utilize dinuclear metal cofactors (Fe/Fe or Mn/Fe).
- Previous work established cofactor capability for tyrosine-valine ether cross-link formation.
- In vitro studies show Mn/Fe cofactor assembly is preferred with Mn(II) and Fe(II).
Purpose of the Study:
- To compare the catalytic efficiency of Mn/Fe and Fe/Fe cofactors in protein cross-linking.
- To investigate the substrate specificity of the Mn/Fe cofactor by mutating the cross-linking residue.
- To determine the biological relevance of the heterodinuclear cofactor.
Main Methods:
- In vitro biochemical assays to measure cross-link formation.
- Site-directed mutagenesis to alter the valine residue in the protein scaffold.
- Analysis of cofactor activity with different amino acid residues (isoleucine, leucine, alanine).
Main Results:
- Mn/Fe cofactors exhibit higher catalytic efficiency for cross-link formation compared to Fe/Fe cofactors.
- The Mn/Fe cofactor successfully catalyzed cross-linking with isoleucine's tertiary beta-carbon.
- Cross-linking was not observed with leucine or alanine residues, indicating high specificity.
Conclusions:
- The heterodinuclear Mn/Fe cofactor is likely the biologically relevant form due to its enhanced catalytic activity.
- The R2-like oxidase cofactor displays high substrate specificity, directing reactivity towards specific amino acid side chains.
- Mutational analysis reveals precise chemical potential and directed reactivity of the Mn/Fe cofactor.
Keywords:
Di-metal carboxylate proteinFerritinR2-like ligand-binding oxidaseRibonucleotide reductaseX-ray crystallographyMore Related Videos
Related Concept Videos
00:49Ligand Binding and Linkage
5.6K
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence...
5.6K
00:49Ligand Binding and Linkage
4.1K
4.1K
02:40Ligand Binding Sites
15.1K
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
15.1K
02:40Ligand Binding Sites
8.9K
8.9K
02:51Metal-Ligand Bonds
24.4K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
24.4K
02:18The Equilibrium Binding Constant and Binding Strength
15.1K
The equilibrium binding constant (Kb) quantifies the strength of a protein-ligand interaction. Kb can be calculated as follows when the reaction is at equilibrium:
15.1K