Related Experiment Video
Updated: Jun 19, 2026
06:12
Mechanical Separation and Protein Solubilization of the Outer and Inner Perivitelline Sublayers from Hen's Eggs
Published on: January 27, 2021
THE SULFHYDRYL GROUPS OF EGG ALBUMIN
1Laboratories of The Rockefeller Institute for Medical Research, Princeton, New Jersey.
The Journal of General Physiology
|October 30, 2009
Summary
This study shows that sulfhydryl (SH) groups in denatured egg albumin react with various reagents, with reaction rates varying by chemical. Guanidine hydrochloride purity is crucial for accurate SH group analysis.
Area of Science:
- Biochemistry
- Protein Chemistry
Background:
- Sulfhydryl (SH) groups in proteins are crucial for structure and function.
- Denatured egg albumin provides a model system for studying SH group reactivity.
Purpose of the Study:
- To investigate the reaction kinetics and conditions affecting the abolition of SH groups in denatured egg albumin.
- To compare the reactivity of different reagents with SH groups in denatured and native egg albumin.
Main Methods:
- Titration of SH groups using ferricyanide, tetrathionate, and p-chloromercuribenzoate.
- Utilizing nitroprusside and ferricyanide reduction tests to confirm SH group abolition.
- Investigating the effects of guanidine hydrochloride purity and cyanide on SH group reactions.
Main Results:
- Ferricyanide, tetrathionate, and p-chloromercuribenzoate abolish SH groups in denatured egg albumin, with ferricyanide and p-chloromercuribenzoate reacting faster.
- The reduction of ferricyanide to ferrocyanide by SH groups is largely independent of ferricyanide concentration.
- Cyanide inhibits ferricyanide oxidation of SH groups, and guanidine hydrochloride impurities can interfere with SH analysis.
Conclusions:
- The reactivity of SH groups in denatured egg albumin varies with the reagent and reaction conditions.
- Careful control of reagents, particularly guanidine hydrochloride purity, is essential for accurate SH group quantification.
- Native egg albumin exhibits different reactivity patterns with p-chloromercuribenzoate compared to denatured forms.
Related Concept Videos
01:25Protein Folding
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
01:22Protein Folding
Overview
02:15Protein and Protein Structure
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme can...
A protein's shape is critical to its function. For example, an enzyme can...
03:42Amino acids
Amino acids are the monomers that comprise proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom. Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. There are 20 common amino acids present in proteins, each with a different R group. Variation in the amino acid sequence is responsible for...
01:26Protein Modifications in the RER
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
02:17Structure and Nomenclature of Thiols and Sulfides
Thiols and sulfides are sulfur analogs of alcohols and ethers, respectively, where the sulfur atom takes the place of the oxygen atom. Thus, thiols are generally represented as RSH, where R is an alkyl substituent and —SH is the functional group. On the other hand, in sulfides, the central sulfur atom is bonded to two hydrocarbon groups on either side. Depending upon the type of group, sulfides can be either symmetrical or asymmetrical. Both thiols and sulfides display a bent geometry, similar...