Arabinosylated

Arabinosylated is a term used to describe a molecule that contains one or more arabinose sugar residues covalently attached through glycosidic bonds. Arabinose is a five‑carbon monosaccharide, with L‑arabinose being the form most common in plants. When a substance bears arabinose units—whether as short branches on proteins or as side chains on polysaccharides—it is described as arabinosylated.

In biological systems, arabinosylation is a widespread form of glycosylation, particularly in plants. Common contexts include hydroxyproline-rich glycoproteins, such as extensins, and arabinogalactan proteins (AGPs), which receive arabinose-containing chains on hydroxyproline residues. Arabinan chains also decorate certain pectic polysaccharides in the cell wall. The addition of arabinose is typically catalyzed by arabinosyltransferases that use UDP‑arabinose as the sugar donor, a subset of which are known as hydroxyproline O‑arabinosyltransferases.

Functionally, arabinosylation can influence protein stability, solubility, and interactions, and it contributes to the architecture and porosity of the plant cell wall. In AGPs and extensins, arabinosyl residues are thought to affect cell expansion, signaling, and defense responses. Outside plants, arabinosylation can occur in fungi and bacteria, where it may affect cell surface properties and host interactions.

Detection and study of arabinosylated structures employ methods such as mass spectrometry, nuclear magnetic resonance spectroscopy, and specific antibodies or enzymes that recognize arabinose-containing epitopes.