This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
Ligand
From Proteopedia
(adding content) |
(polishing) |
||
| Line 1: | Line 1: | ||
| - | In its usual sense, ''' | + | In its usual sense, '''ligand''' denotes a small molecule bound non-covalently to a macromolecule. The binding is reversible. Examples: Receptors bind hormone and cytokine ligands, and enzymes bind substrate or inhibitor ligands. Avidin binds the ligand biotin. |
See also [http://en.wikipedia.org/wiki/Ligand_%28biochemistry%29 ''Ligands (Biochemistry)'' in Wikipedia]. | See also [http://en.wikipedia.org/wiki/Ligand_%28biochemistry%29 ''Ligands (Biochemistry)'' in Wikipedia]. | ||
Revision as of 15:23, 25 June 2008
In its usual sense, ligand denotes a small molecule bound non-covalently to a macromolecule. The binding is reversible. Examples: Receptors bind hormone and cytokine ligands, and enzymes bind substrate or inhibitor ligands. Avidin binds the ligand biotin. See also Ligands (Biochemistry) in Wikipedia.
In macromolecular structure, ligand has a specialized meaning derived from the way in which the PDB file format is structured. All atoms in PDB files are classified into two groups: atoms in protein or nucleic acid chains, identified with the ATOM record type, and all other atoms, which are identified with the HETERO record type.
Many visualization and modeling programs further divide hetero atoms into solvent and non-solvent atoms. Solvent includes water and common anions such as sulfate and phosphate. These programs (e.g. RasMol, Chime, and Jmol) often define ligand to include all non-solvent
