Search results
Results from the WOW.Com Content Network
N-linked glycosylation is the attachment of an oligosaccharide, a carbohydrate consisting of several sugar molecules, sometimes also referred to as glycan, to a nitrogen atom (the amide nitrogen of an asparagine (Asn) residue of a protein), in a process called N-glycosylation, studied in biochemistry. [1]
N-linked glycosylation is a very prevalent form of glycosylation and is important for the folding of many eukaryotic glycoproteins and for cell–cell and cell–extracellular matrix attachment. The N-linked glycosylation process occurs in eukaryotes in the lumen of the endoplasmic reticulum and widely in archaea, but very rarely in bacteria.
N-Linked glycosylation involves oligosaccharide attachment to asparagine via a beta linkage to the amine nitrogen of the side chain. [7] The process of N -linked glycosylation occurs cotranslationally, or concurrently while the proteins are being translated.
The most common method of glycosylation of N-linked glycoproteins is through the reaction between a protected glycan and a protected Asparagine. [5] Similarly, an O-linked glycoprotein can be formed through the addition of a glycosyl donor with a protected Serine or Threonine. [5] These two methods are examples of natural linkage. [5]
The most important of these to note are N-linked glycosylation and disulfide bond formation. N-linked glycosylation occurs as soon as the protein sequence passes into the ER through the translocon, where it is glycosylated with a sugar molecule that forms the key ligand for the lectin molecules calreticulin (CRT; soluble in ER lumen) and ...
N-linked glycosylation is an important process, especially in eukaryotes where over half of all proteins have N-linked sugars attached [13] and where it is the most common form of glycosylation. [23] The processes are also important in prokaryotes [13] and archaeans. [24]
Paucimannosylation has traditionally been referred to as a N-glycosylation type of "lower organisms", [3] mostly documented in insects, worms and plants. Recent findings have, however, added nuances to this view, by showing their presence and roles in mammals in the areas of immunity, cellular development, pathogen infection and cancer.
The sequon for N-glycosylation is either Asn-X-Ser or Asn-X-Thr, where X is any amino acid except proline, Ser denoting serine and Thr threonine. Occasionally, other amino acids can take the place of Ser and Thr, such as in the leukocyte surface protein (CD69), where the amino acid sequence Asn-X-Cys is an acceptable sequon for the addition of ...