Relations between vitamin D and fatty acid binding properties of vitamin D-binding protein.
The interaction of fatty acids with bovine vitamin D-binding protein (DBP) was studied using a partition equilibrium method. This protein has one high affinity site for binding of fatty acids with an association constant Ka = 7 x 10(5) M-1 for palmitic acid and Ka = 6 x 10(5) M-1 for arachidonic acid. Competition experiments showed that palmitic acid hardly competes with 25-hydroxycholecalciferol for binding to DBP. However, arachidonic acid showed comparatively a stronger competition for binding to this protein. The great difference in competition of palmitic and arachidonic acids with 25-hydroxycholecalciferol may be related to changes in DBP conformation promoted by the binding of different ligands.
Calvo
M
M
Technología y Bioquímica de los Alimentos, Facultad de Veterinaria de Zaragoza, Spain.
Ena
J M
JM
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D001667:Binding, Competitive; D002112:Calcifediol / Q000378:metabolism; D002417:Cattle; D005227:Fatty Acids / Q000378:metabolism*; D066298:In Vitro Techniques; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D011485:Protein Binding; D014807:Vitamin D / Q000378:metabolism*; D014809:Vitamin D-Binding Protein / Q000378:metabolism*
D001095:Arachidonic Acids; D005227:Fatty Acids; D010169:Palmitic Acids; D014809:Vitamin D-Binding Protein; D014807:Vitamin D; D016718:Arachidonic Acid; D019308:Palmitic Acid; D002112:Calcifediol