Glutamyl Ribose-5-Phosphate Storage Disease: Clinical Description and Characterization of the Stored Material

Abstract

Posttranslational processing of proteins involves conformational changes, formation and cleavage of peptide bonds, and chemical modification of amino acid residues. These events are assumed to have evolved for specific purposes, such as protection from degradation, binding to specific macromolecules, and regulation of physiological processes. Posttranslational covalent modification of amino acid moieties in proteins is a diverse process resulting in more than 130 derivatives of the 20 primary amino acids [1]. The formation of glycoproteins by the enzymatic addition of carbohydrate to amino acids and the subsequent elongation to form oligosaccharide chains has become a major area of investigation in recent years. In glycoconjugate synthesis, ADP-ribosylation is unique in that it involves an initial linkage of ADP-ribose via the ribosyl moiety and, in the case of poly(ADP-ribosylation), subsequent elongation with additional ADP-ribose units.