xylosylated

Xylosylation is a process in biochemistry where an xylopyranoside moiety is attached to a substrate or molecule. This functional group is composed of a five-carbon sugar called xylose. Xylosylation is an example of a glycosylation reaction, in which a carbohydrate molecule, or glycosyl donor, combines with another molecule to form a glycosidic bond.

In the context of biological systems, xylosylation is a common modification of proteins and other molecules, particularly in the Golgi apparatus, a structure within eukaryotic cells responsible for protein and lipid synthesis. This post-translational modification contributes to the structural and functional properties of proteins.

The process involves the transfer of an xylose residue from an activated xylose donor to a protein or other molecule, typically through the assistance of enzymes such as xylosyltransferase. This reaction is reversible.

In certain organisms, including mammals, xylosylation is crucial for protein glycosylation, particularly O-linked glycosylation. This type of glycosylation links carbohydrates to the hydroxyl group of serine or threonine residues in proteins. The xylose residue added to the protein serves as a primer for subsequent addition of other carbohydrate components, leading to the formation of more complex carbohydrate moieties.

The significance of xylosylation lies in its role in various biological processes, including cell-cell adhesion, immune system function, and the folding and stability of proteins. Dysregulation of this process can be linked to various diseases and disorders.