isopeptide bond

(redirected from Isopeptide)

i·so·pep·tide bond

an amide linkage between a carboxyl group of one amino acid and an amino group of another amino acid in which at least one of these groups is not on the α-carbon of one of the amino acids; for example, the bond between the glutamyl residue and the cysteinyl residue of glutathione. Compare: peptide bond, eupeptide bond.
References in periodicals archive ?
Fibrin cross-linking is a highly specific acyl transfer reaction consisting of two steps: (1) glutamine of the substrate forms a binary complex with the active site cysteine of the enzyme through the thioester linkage, accompanied by ammonia release; (2) the acyl group of the binary complex is transferred to the acyl acceptor amine and form an isopeptide, releasing the enzyme at the same time.
These chains are formed by the successive attachment of monomers by an isopeptide bond, most frequently formed between the side chain of Lys-48 in one ubiquitin and the carboxyl group of the C-terminal Gly-76 of a neighbouring ubiquitin.
37) The additional carbon in the homocysteine side chain permits it to exist as a thiolactone, which reacts with the Lys residues to form isopeptide bonds.
We have designed a unique way to connect protein building blocks irreversibly and precisely, via spontaneous isopeptide bond formation.
Management of the virulent influenza virus infection by oral formulation of nonhydrolized carnosine and isopeptide of carnosine attenuating proinflammatory cytokine-induced nitric oxide production.
No such improvement was observed in the protein quality of the experimental diet T6 containing roasted SB seeds, which might be due to the fact that dry heat treatment could have led to formation of isopeptide bonds.
Other reactions that proceed with longer heat processing time, such as isopeptide cross-links involving amino acids, such as lysine and serine (Finley, 1989), asparagines and glutamine (Hurrell and Carpenter, 1977), and methionine and tryptophan (Broderick et al.
He noted that aging slows ubiquitin-proteasome proteolytic activity, resulting in the accumulation of ubiquitinylated proteins via isopeptide bonds.
The autoantigen tTG is a calcium-dependent enzyme that catalyzes an acyl transfer between the gamma]-carboxamide group of a polypeptide-bound glutamine and the [member of]-amino group of a polypeptide-bound lysine residue to form an isopeptide bond (10,11).
As you may know, transglutaminase is a transferase that forms isopeptide bonds between lysyl and glutaminyl residues.
Epsilon]]([Gamma]-glutamyl) lysine isopeptide bond between the [Gamma]-amide sidechain of a donor glutamine residue and the [Epsilon]-N[H.