Ligand Binding
Due to the acidic nature of sialic acid, Siglec active sites contain a conserved arginine residue which is positively charged at physiological pH. This amino acid forms salt bridges with the carboxyl group of the sugar residue. This is best seen in Sialoadhesin, where arginine at position 97 forms salt bridges with the COO- group of the sialic acid, producing a stable interaction. Each lectin domain is specific for the linkage that connects sialic acid to the glycan. Sialic acid contains numerous hydroxyl groups which can be involved in the formation of glycosidic linkages. Most sialic acids are bonded via the 2, 3, 6 and occasionally 8 hydroxyl groups (number dependent on the carbon to which they are attached), in an α anomeric configuration. The specificity of each Siglec is due to different chemical interactions between the sugar ligand and the Siglec amino acids. The position in space of the individual groups on the sugar and the protein amino acids affects the sialic acid linkage to which each Siglec binds. For example, Sialoadhesin preferentially binds α2,3 linkages over α2,6 linkages.
Other articles related to "ligand binding, binding, ligand, ligands":
... On ligand binding, forms a receptor complex consisting of two type II and two type I transmembrane serine/threonine kinases ... Binding is weak but enhanced by the presence of type I receptors for BMPs In TGF beta signaling all of the receptors exist in homodimers before ligand binding ... fraction of the receptors exist in homomeric forms before ligand binding ...
... deactivated) through their signal-sensing domain by a number of mechanisms including ligand binding – Not only is ligand binding able to influence where a transcription factor is located ...
... helices forming a cavity within the plasma membrane that serves a ligand-binding domain that is often covered by EL-2 ... Ligands may also bind elsewhere, however, as is the case for bulkier ligands (e.g ... The class C GPCRs are distinguished by their large N-terminal tail, which also contains a ligand-binding domain ...
... at position 46 (R46) are critical for binding with AVP and AVP agonists, with E54 likely to interact with AVP and R46 to contribute to a conformational switch ... Competitors of Tyr-Phaa-specific binding to AVPR1A include linear V1a antagonist phenylacetyl-D-Tyr(Et)-Phe-Gln-Asn-Lys-Pro-Arg-NH2 (Ki = 1.2 ± 0.2 nM) linear V1a non-p ...
Famous quotes containing the word binding:
“What is lawful is not binding only on some and not binding on others. Lawfulness extends everywhere, through the wide-ruling air and the boundless light of the sky.”
—Empedocles 484–424 B.C., Greek philosopher. The Presocratics, p. 142, ed. Philip Wheelwright, The Bobbs-Merrill Co., Inc. (1960)