Sandbox Reserved 779: Difference between revisions
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'''β-Lactoglobulin''' | '''β-Lactoglobulin''' | ||
<Structure load='1beb' size=' | <Structure load='1beb' size='320' frame='true' align='right' caption='3D model 1._The dimer interface of β-lactoglobulin lattice X_1BEB' scene='Insert optional scene name here' /> | ||
=='''β-Lactoglobulin'''== | =='''β-Lactoglobulin'''== | ||
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Co-crystallized β-Lg with palmitic acid (3D Model 2._1B0O) , and the refined structure reveals that the ligand binds in the central cavity in a manner similar to the binding of retinol to the related lipocalin, serum retinol-binding protein. The carboxyl group binds to both Lys-60 and Lys-69 at the entrance to the cavity. The hydrophobic tail stretches in an almost fully extended conformation into the center of the protein.<ref>PMID:9867826</ref> | Co-crystallized β-Lg with palmitic acid (3D Model 2._1B0O) , and the refined structure reveals that the ligand binds in the central cavity in a manner similar to the binding of retinol to the related lipocalin, serum retinol-binding protein. The carboxyl group binds to both Lys-60 and Lys-69 at the entrance to the cavity. The hydrophobic tail stretches in an almost fully extended conformation into the center of the protein.<ref>PMID:9867826</ref> | ||
In addition, studies on the monomer–dimer equilibrium and the reactivity of the thiol group of Cys121 which deeply buried between the α-helix and H strand revealed other important properties of β-LG. The stability of the structure also depend so heavily upon the external loop around residue 64 or the β strand with the free thiol.<ref>PMID:9115437</ref> | In addition, studies on the monomer–dimer equilibrium and the reactivity of the thiol group of Cys121 which deeply buried between the α-helix and H strand revealed other important properties of β-LG. The stability of the structure also depend so heavily upon the external loop around residue 64 or the β strand with the free thiol.<ref>PMID:9115437</ref> | ||
[[Image:Vitamin D3 binding to the beta-lac calyx and dimer interface.jpg|thumb|left|240px|Figure 4. Vitamin D3 binding to the beta-lac calyx and dimer interface | [[Image:Vitamin D3 binding to the beta-lac calyx and dimer interface.jpg|thumb|left|240px|Figure 4. Vitamin D3 binding to the beta-lac calyx and dimer interface (Dominguez-Ramirez et al, 2013)<ref>PMID:24255705</ref>]] | ||
β-Lg has binding sites for hydrophobic ligands like fatty acids, retinoic acid, and Vitamin D3 (cholecalciferol) and lactose [[ligands]] <ref>PMID:24255705</ref> For hydrophobic ligands two sites have been postulated, one inside the calyx and the other at the dimer interface, on the outer surface of the protein between the α-helix and the β-barrel (Fig. 4). The accessibility to the calyx is pH-dependent. | β-Lg has binding sites for hydrophobic ligands like fatty acids, retinoic acid, and Vitamin D3 (cholecalciferol) and lactose [[ligands]] <ref>PMID:24255705</ref> For hydrophobic ligands two sites have been postulated, one inside the calyx and the other at the dimer interface, on the outer surface of the protein between the α-helix and the β-barrel (Fig. 4). The accessibility to the calyx is pH-dependent. | ||
NMR and Xray analysis showed that the access is mediated by the mobile EF loop. All the structures with ligands bound to the calyx exhibit an open EF loop, suggesting that this site is accessible at neutral pH. | NMR and Xray analysis showed that the access is mediated by the mobile EF loop. All the structures with ligands bound to the calyx exhibit an open EF loop, suggesting that this site is accessible at neutral pH. | ||
<Structure load='1b0o' size=' | <Structure load='1b0o' size='320' frame='true' align='right' caption='3D model 2._β-lactoglobulin complexed with Palmitate, lattice Z_1B0O' scene='Insert optional scene name here' /> | ||
====Biological role==== | ====Biological role==== | ||
