Overview S-Nitrosylation is a post-translational modification in which a nitric oxide molecule is bound via a reactive thiol group of a cysteine residue. S-nitrosylation has various regulatory roles in bacteria, yeasts, plants and mammalian cells. pKa NC Loss Gain Deltamass H AA UV-Spec Pattern – No H NO Av: 28.9982M: 28.9902 – C Yes – […]
Posts in the Bioinformatics category:
Bioinformatics is an interdisciplinary field that develops methods and software tools for understanding biological data. As an interdisciplinary field of science, bioinformatics combines computer science, statistics, mathematics, and engineering to study and process biological data. (From Wikipedia, Bioinformatics)
ADP-Ribosylation
ADP-ribosylation is a reversible post-translational modification in which one (mono-ADP-ribosylation) or multiple (poly-ADP-ribosylation) ADP-ribose moieties are attached onto a substrate protein by ADP ribosyltransferases. mono-ADP-Ribosylation Overview mono-ADP-ribosylation is a common post-translational modification, where an ADP-ribose moiety is transferred from NAD+ to the substrate protein under the release of nicotinamide. The transfer of ADP-ribose occurs onto […]
Citrullination
Overview Citrulline is a non-proteinogenic amino acid that is produced through post-translational deimination of peptidyl-arginine. Peptidyl-arginine deiminases catalyze the hydrolysis of a guanido group into an urea group. This modifications affects the formation of hydrogen bonds and therefore protein folding. pKa NC Loss Gain Deltamass H AA UV-Spec Pattern – No NH O Av: 0.9848M: […]
Prenylation
Prenylation covers two post-translational modifications in which one or two isoprenoid moieties, either farnesyl or geranylgeranyl moieties, are attached to a conserved cysteine residue via thioether bond at or near the C-terminus. Most prenylated proteins contain a CAAX motif at the C-terminus. The CAAX motif is a sequence of four amino acids, where “C” stands […]
C-Mannosylation
Overview C-Mannosylation is a unique type of protein glycosylation. A C-C bond is formed between the C1 atom of an α-mannose and the C2 atom of the indole ring of a tryptophan residue via mannosyl-transferases. pKa NC Loss Gain Deltamass H AA UV-Spec Pattern – No H C6H11O5 Av: 162.1408M: 162.0528 0 W – W(?=..W) […]
O-Sulfation
Overview O-Sulfation is a common post-translational modification of tyrosine residues in eukaryotes, but has not been observed in yeast and prokaryotes. Sulfation is limited to secretory and trans-membrane proteins that have passed the trans-Golgi network, where two membrane-bound tyrosylprotein sulfotransferase enzymes catalyze the transfer of sulfate from adenosine 3’-phosphate5’-phosphosulfate to the tyrosine phenol. pKa NC […]
Nitration
Overview Nitration is a post-translational modification of mostly tyrosine residues that is caused by one-electron oxidation. First, a tyrosine radical is formed by one-electron oxidation followed by a reaction with nitrogen dioxide resulting in 3-nitrotyrosine. pKa NC Loss Gain Deltamass H AA UV-Spec Pattern Acidic7.25 No H NO2 Av: 44.9976M: 44.9851 – Y Yes* – […]
Amidation
Amidation is one of the most common post-translational modification in which the C-terminal carboxyl group is replaced by an amide group1–5. Amidation plays an important role in peptidesand peptide hormones. More than half of all mammalian peptide hormones and more than 80 % of all insect hormones have amidated C-termini1. The mechanism of amidation is […]
A mass spectrometry imaging software: Quantinetix™
ImaBiotech, founded in 2009 by a team of experts, offers new molecular imaging (called MALDI imaging) services and products to life science industries. This new technology is capable of visualizing and quantifying biological compounds that play role in many pathologies like Cancer, Alzheimer or Parkinson diseases. It is also an interesting tool to follow new […]
Prediction of potential modification sites in proteins
Some sequence motifs in proteins tend to be modified. Thus, for example an N-terminal glutamine or glutamic acid residue can spontaneously lead to a cyclization. This reaction results in an N-terminal pyroglutamic acid with elimination of ammonia or water, respectively. Aspartyl and asparaginyl deamidation, isomerization, and racemization reactions can spontaneously occur, if the subsequent amino acid […]