fattyacyl

Fattyacyl, typically written fatty acyl, refers to an acyl group derived from a fatty acid. In biochemistry, an acyl group is the carbonyl-containing fragment R-CO– that remains when a fatty acid loses its hydroxyl group. Fatty acyl groups are the hydrophobic tails of lipids and other molecules, and they can be attached to glycerol backbones, sphingolipids, or proteins, contributing to membrane structure and signaling.

Chemical characteristics and naming: Fatty acyl chains vary in length and degree of unsaturation, commonly ranging from short to very long chains. Common examples include palmitoyl (C16:0), stearoyl (C18:0), oleoyl (C18:1), myristoyl (C14:0), and arachidonoyl (C20:4). These groups can be saturated or unsaturated and are typically nonpolar, hydrophobic components of complex lipids. Attachment to other molecules occurs via covalent bonds, often through thioester or amide linkages formed by specialized transferases.

Biological roles and metabolism: In cells, fatty acyl groups are activated to fatty acyl-CoA thioesters by acyl-CoA synthetases, enabling entry into beta-oxidation for energy production or into lipid biosynthesis pathways for storage and membrane formation. Fatty acyl-CoA species serve as substrates for the assembly of triglycerides and phospholipids and as donors in post-synthetic lipid modifications of proteins.

Protein lipidation and regulation: Fatty acyl groups participate in protein lipidation, notably S-acylation, where a palmitoyl (or other fatty acyl) group is covalently attached to cysteine residues. This modification influences protein localization, trafficking, and signaling.

See also: fatty acids, acyl-CoA, lipidation.