Related Experiment Video
Updated: Mar 13, 2026
10:23
Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells
Published on: December 13, 2016
10.5K
Probing bulky ligand entry in engineered archaeal ferritins
Lorenzo Calisti1, Irene Benni1, Matilde Cardoso Trabuco1
1Department of Biochemical Sciences "Alessandro Rossi Fanelli", Sapienza University of Rome, P.le Aldo Moro 5, I-00185 Rome, Italy.
Biochimica Et Biophysica Acta. General Subjects
|October 26, 2016
Summary
Engineered archaeal ferritins (Af-Ft and Pf-Ft) with internal or external thiols show that their protein matrix readily allows bulky ligands like DTNB to enter the internal cavity, crucial for biotechnological applications.
Area of Science:
- Biochemistry
- Structural Biology
- Biotechnology
Background:
- Engineered ferritin mutants from Archaeoglobus fulgidus (Af-Ft) and Pyrococcus furiosus (Pf-Ft) were created with cysteine thiols at specific locations.
- Af-Ft possesses a wide surface aperture, while Pf-Ft has canonical channels, serving as models for internal cavity accessibility.
Purpose of the Study:
- To investigate the permeation properties of archaeal ferritin protein matrices.
- To assess the accessibility of the ferritin internal cavity to bulky thiol-reactive molecules.
Main Methods:
- Kinetic experiments were used to probe thiol reactivity.
- The bulky thiol-reactive molecule 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) was employed.
Main Results:
- DTNB reacted with thiols in all ferritin mutants, including those with internal thiols.
- Pf-Ft mutants with external thiols showed the fastest DTNB binding kinetics.
- Pf-Ft mutants with internal thiols exhibited slower but complete DTNB binding, with Af-Ft mutants showing intermediate behavior.
Conclusions:
- The protein matrix of archaeal ferritins does not significantly hinder bulky, negatively charged ligands like DTNB.
- This finding is important for biotechnological applications involving ligand encapsulation within ferritin cavities.
Related Concept Videos
02:51Metal-Ligand Bonds
25.3K
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...
25.3K
02:40Ligand Binding Sites
15.6K
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...
15.6K
02:40Ligand Binding Sites
9.0K
9.0K
00:49Ligand Binding and Linkage
5.9K
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...
5.9K
02:58Crystal Field Theory - Octahedral Complexes
31.5K
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...
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...
31.5K
00:43Complexometric Titration: Ligands
2.5K
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...
2.5K