Practical Protein Chemistry - A. Darbre 1989
Enzymatic fragmentation of the polypeptide chain
Protein modification methods
Cleavage of disulfide bonds
Prior to proteolytic Hydrolysis, most Proteins must be chemically modified. This modification typically involves the Cleavage of Disulfide Bonds, followed by reduction and subsequent alkylation to yield stable Cysteine derivatives. In the case of aminoethylation, the modified cysteine residues serve as additional cleavage sites for Trypsin and the protease from A. mellea. Occasionally, modification of aspartic acid residues is also employed, which likewise creates supplementary sites for tryptic hydrolysis.
Modification of Lysine and Arginine residues is used to limit the action of trypsin. Of particular interest are reversible modification Methods, which allow the original amino acid residues to be regenerated following Enzymatic hydrolysis.
3.4.1.1. Oxidation. The cleavage of Disulfide Bonds via performic acid oxidation yields stable cysteic acid residues and increases the overall negative charge of the polypeptide chain. A detailed Structure/133.html">Discussion of this method, along with practical recommendations, can be found in Section 2.2.3.
3.4.1.2. Reduction. Methods for the reduction of disulfide bonds are described in detail in Chapter 2 and in [55].
Last update: 06/08/2026
Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.
What was processed:
- elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
- editorial organization of content;
- standardization of terminology in accordance with academic sources;
- verification of factual statements against the original source text.
All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.