Disulfide Bonds
Disulfide Bonds - Related Videos
03:51
Fluorescent Functionalization of Virus-Like Particles via Disulfide Re-bridging
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2026
Source: Chen, Z., et al. Making Conjugation-induced Fluorescent PEGylated Virus-like Particles by Dibromomaleimide-disulfide Chemistry. J. Vis. Exp. (2018)This video demonstrates the fluorescent functionalization of virus-like particles by re-bridging reduced disulfides with a polyethylene glycol (PEG) linker, producing stable, trackable conjugates suitable for cellular imaging and targeted delivery in biomedical applications.
02:44
Non-Reducing SDS PAGE: A Method to Analyze Disulfide-Linked Multimeric Protein Complexes
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2025
This video describes the technique of separating the protein samples by non-reducing SDS-PAGE to analyze the multimeric protein complexes. This technique retains the multimer subunits of a protein held by the disulfide bonds which can later be analyzed by western blotting.
10:18
Making Conjugation-induced Fluorescent PEGylated Virus-like Particles by Dibromomaleimide-disulfide Chemistry
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Cited by 12 •
2018
Here, we present a procedure to fluorescently functionalize the disulfides on Qβ VLP with dibromomaleimide. We describe Qβ expression and purification, the synthesis of dibromomaleimide-functionalized molecules, and the conjugation reaction between dibromomaleimide and Qβ. The resulting yellow fluorescent conjugated particle can be used as a fluorescence probe inside cells.
02:49
Bond Energies and Bond Lengths
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2020
Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, that is, the energy necessary to separate the bonded atoms. Separating any pair of bonded atoms requires energy — the stronger a bond, the greater the energy required to break it. The energy required to break a specific covalent bond in one mole of gaseous molecules is called the bond energy or the bond dissociation energy. The bond energy for a...
02:32
Bonding in Metals
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2020
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”. Electron Sea Model Most metal atoms do not possess enough valence electrons to enter into an ionic or covalent bonding. However, the valence electrons in metal atoms are loosely held due to their low electronegativity or attraction with the nucleus. The ionization energy of metal atoms (energy required to remove an electron from...
FAQs
Oxidation removes hydrogen from the thiol groups of two cysteine residues, allowing their sulfur atoms to form a covalent sulfur-sulfur link. This reaction changes the relationship between the residues and can lock parts of a protein into a more stable arrangement. Reducing conditions reverse the process by breaking the sulfur-sulfur bond.
The locations of cysteine residues determine which regions of a protein can be connected by disulfide bonds. Once formed, these links help stabilize particular three-dimensional arrangements rather than leaving the chain fully flexible. Consequently, cysteine placement can influence folding, structural integrity, and the final activity of proteins such as enzymes or hormones.
Extracellular proteins encounter chemical and physical conditions that can challenge their structure. Disulfide bonds reinforce the protein's three-dimensional organization, helping it resist these stresses. This stabilizing role is particularly important for proteins that must remain folded and functional outside cells, where structural reinforcement supports persistence and biological activity.
Disulfide-bond analysis can provide information about how cysteine residues contribute to a protein's three-dimensional structure and stability. It can also help examine changes associated with folding, bond formation, or bond disruption under reducing conditions. These observations support investigations of protein behavior in cell biology, disease research, and biopharmaceutical development.
Within antibodies, disulfide bonds help maintain the relationships among protein regions that produce their characteristic architecture. By reinforcing three-dimensional organization, the bonds support the structural arrangement required for antibody molecules to remain intact. Examining these links is therefore relevant when studying antibody structure, folding, and stability in biological or biopharmaceutical contexts.
Disulfide bonds can influence whether hormones and enzymes maintain the structures needed for their activity. Formation during protein folding may stabilize the relevant three-dimensional arrangement, whereas bond disruption under reducing conditions can alter that organization. Studying these changes helps connect protein chemistry with biological function and supports research into disease and therapeutic development.