Chemical and Functional Aspects of Posttranslational Modification of Proteins

Abstract

This paper reviews the chemical and functional aspects of the posttranslational modifications of proteins, which are achieved by the addition of various groups to the side chain of the amino acid residue backbone of proteins. It describes the main prosthetic groups and the interaction of these groups and the apoenzyme in the process of catalysis, using pyridoxal catalysis as an example. Much attention is paid to the role of posttranslational modification of proteins in the regulation of biochemical processes in live organisms, and especially to the role of protein kinases and their respective phosphotases. Methylation and acetylation reactions and their role in the "histone code", which regulates genome expression on the transcription level, are also reviewed. This paper also describes the modification of proteins by large hydrophobic residues and their role in the function of membrane-associated proteins. Much attention is paid to the glycosylation of proteins, which leads to the formation of glycoproteins. We also describe the main non-enzymatic protein modifications such as glycation, homocysteination, and desamida-tion of amide residues in dibasic acids.

Methanethiosulfonate Derivative of OX063 Trityl: A Promising and Efficient Reagent for Side‐Directed Spin Labeling of Proteins

“…This heterogeneity of natural HSA complicates biophysical studies, but it is central to its biological and physiological function and is an obvious target for future spin label EPR studies. Fortunately, the importance and abundance of HSA comes along with an extensive knowledge base with many bioanalytical methods developed specifically regarding Cys34 and covalent aggregates of HSA that were useful in this study –…”

Homocysteine in Protein Structure/Function and Human Disease

“…N-Hcy-proteins are novel examples of modified proteins that expand the known repertoire of nonenzymatic protein modifications [322] by other metabolites, such as glucose, products of lipid peroxidation, or certain drugs, such as penicillin or aspirin [78]. These protein modification reactions share two common aspects: (i) each involves protein lysine residues as sites of modifications and (ii) are linked to human pathology, such as cardiovascular disease, Alzheimer's disease, diabetes, and drug allergy or intolerance [78].…”

A Targeted, Differential Top-Down Proteomic Methodology for Comparison of ApoA-I Proteoforms in Individuals with High and Low HDL Efflux Capacity

“…37–38 However, most ApoA-I PTMs observed result from enzymatic activity (acylations, phosphorylation and backbone cleavages) or endogenous reactions (glycations), and thus the relative abundance of the related proteoforms characterized in this study are likely representative of endogenous modification states of ApoA-I. 39 Finally, any extraction bias was distributed across samples from all individuals and, while absolute concentration of proteoforms is not inferable from the data, relative variations in proteoforms intensity are representative of biological changes.…”