Isopeptide bonds lead to branching in the primary sequence of a protein. Proteins formed from normal peptide bonds typically have a linear primary sequence. Amide bonds, and thus isopeptide bonds, are stabilized by resonance (electron delocalization) between the carbonyl oxygen, the carbonyl carbon, and the nitrogen atom. The bond strength of ...

2011年4月1日 · Isopeptide bonds formed through lysine residues mediate several crucial biological processes through their intermolecular cross-linking of proteins. Examples include ubiquitylation [5], sumoylation [6], transglutamination [7], sortase-mediated cell surface protein anchoring [8] and pilus formation (Figure 1) 9, 10.

2023年11月9日 · An isopeptide bond is an amide bond between the sidechain of one amino acid and the sidechain or main chain terminus of another amino acid, or a ligand. Isopeptide bonds are sometimes called lactams. Isopeptide bonds can form …

2017年2月16日 · The discovery of stabilizing isopeptide bond crosslinks, formed spontaneously between lysine and asparagine (or aspartic acid) side chains in certain bacterial cell-surface proteins suggests that...

An isopeptide bond is an amide bond in a protein connecting a side chain to a side chain or a side chain to the protein's main chain (Figure 1 A). Important natural examples of isopeptide bonds include ATP-dependent conjugation of ubiquitin to proteins [17] and transglutaminase-catalyzed isopeptides imparting strength to hair, skin, and blood ...

Some lasso peptide biosynthetic clusters harbor an enzyme that specifically hydrolyzes the isopeptide bond to yield the linear peptide. We describe here the 2.4 Å resolution structure of a lasso peptide isopeptidase revealing a topologically novel didomain architecture consisting of an open β-propeller appended to an α/β hydrolase domain.

2011年4月1日 · Proteins tagged with the peptide SpyTag form an irreversible covalent bond to the SpyCatcher protein via a spontaneous isopeptide linkage, thereby offering a genetically encoded way to create peptide interactions that resist force and harsh conditions.

Site-specific isopeptide linkages between the ε-amino group of a lysine residue in one protein and a carboxyl group in another are central to ubiquitin-mediated protein degradation and other cellular processes. These linkages are inaccessible with common recombinant DNA techniques.

2024年12月25日 · The method is described in "Isopeptor: a tool for detecting intramolecular isopeptide bonds in protein structures". Isopeptor can be accessed via this google colab or installed and run locally. Read the documentation for …

Isopeptide bonds are intramolecular covalent bonds that form autocatalytically between the side chains of lysine and asparagine/aspartic acid. These are found to confer high stability to the protein, conveying structural solidity (Wang et al. 2013b).