N-linked glycosylation involves the addition of sugars to which type of amino acid?

N-linked glycosylation specifically involves the attachment of carbohydrate chains to the amino acid asparagine within a specific sequence in protein structures. This glycosylation occurs in the endoplasmic reticulum and Golgi apparatus, where a precursor oligosaccharide is initially added to asparagine residues in proteins that have a consensus sequence, usually denoted as Asn-X-Ser/Thr. In this sequence, "Asn" represents asparagine, "X" can be any amino acid, and "Ser" or "Thr" indicates that either serine or threonine can be present as the next amino acid.

The process enhances protein folding, stability, and cell recognition. Understanding that N-linked glycosylation is precisely correlated with asparagine helps clarify its significant role in the post-translational modification of proteins, contributing to their functional diversity.