Carboxymethyl/Carboxyethyl Lysine (E5C5H) Rabbit mAb #44358

Carboxymethyl lysine (CML) and carboxyethyl lysine (CEL) are two protein post-translational modifications that arise from non-enzymatic pathways and represent examples of advanced glycation end products (AGEs) (1). The association between CML/CEL levels with glucose and oxidant stress levels underlies the use of these modifications as biomarkers for various disease conditions, including diabetes and osteoporosis (2). The Maillard reaction between monosaccharides and lysines can form a Schiff base intermediate that rearranges to become CML/CEL. In addition, fragmentation of the Schiff base intermediate and oxidation of amino acids and polyunsaturated fatty acids produce reactive species, such as glyoxal and methylglyoxal, which react with lysine to form CML/CEL. While CML/CEL exists as free and protein-incorporated forms, in vitro treatment with protein-incorporated CML/CEL in particular induces diverse effects, including reduced serotonin release in gastric cells, impaired calcium homeostasis in cardiac cells, and increased reactive oxygen intermediates in endothelial cells (3-5). These processes depend on receptor for AGE (RAGE) signaling.