N-Ethylmaleimide (NEM) has been much used for the chemical modification of proteins, and it is usually assumed that reaction occurs specifically at the thiol groups of cysteinyl residues. However, NEM has been shown to react also with the acamino group of peptides and with the imidazole group of histidine (Smyth, Nagamatsu & Fruton, 1960), and with the a-amnino group of certain amino acids (Smy...

1. Seven unique carboxymethylcysteine-containing peptides have been isolated from tryptic digests of rabbit muscle aldolase carboxymethylated with iodo[2-(14)C]acetic acid in 8m-urea. These peptides have been characterized by amino acid and end-group analysis and their location within the cyanogen bromide cleavage fragments of the enzyme has been determined. 2. Reaction of native aldolase with ...

Thiol groups in biological molecules play a significant role in various physiological functions and pathological conditions. Thiols are divided into two major groups: protein thiols and nonprotein thiols. Numerous methods have been reported for thiol assays. Most of these methods have been developed for glutathione, the principal nonprotein thiol, despite the fact that cellular protein thiols a...

This review is devoted to relatively new and promising approach the synthesis of novel organic compounds polymer materials, based on “click chemistry” concept. Several types reactions” (cycloaddition, nucleophilic ring opening, non-aldol carbonyl chemistry, addition multiple carbon-carbon bonds) have been described, relevant examples provided. The “thiol-ene” reactions thiol unsaturated functio...

Chemical reactions lie at the heart of many biological processes, from photosynthesis and respiration to cell signaling and drug metabolism. Thanks to an atmosphere rich in oxygen, many organisms use oxygen to carry out these life processes. But oxygen metabolism produces highly toxic by-products called reactive oxygen species. When oxidation outpaces detoxifying reactions, oxidative stress occ...

Chemical reactions lie at the heart of many biological processes, from photosynthesis and respiration to cell signaling and drug metabolism. Thanks to an atmosphere rich in oxygen, many organisms use oxygen to carry out these life processes. But oxygen metabolism produces highly toxic by-products called reactive oxygen species. When oxidation outpaces detoxifying reactions, oxidative stress occ...

Chemical reactions lie at the heart of many biological processes, from photosynthesis and respiration to cell signaling and drug metabolism. Thanks to an atmosphere rich in oxygen, many organisms use oxygen to carry out these life processes. But oxygen metabolism produces highly toxic by-products called reactive oxygen species. When oxidation outpaces detoxifying reactions, oxidative stress occ...