Facilitated calcium diffusion by intestinal calcium-binding protein.
The calcium flux through an aqueous compartment was determined using a flow-through dialysis cell in which two dialysis membranes isolated the aqueous compartment. Addition of the intestinal vitamin D-dependent calcium-binding protein (CaBP) significantly enhanced the calcium flux at near physiological calcium concentrations (1 X 10(-6) M). Bovine serum albumin had no effect on the calcium flux. CaBP appears to be one of a class of low molecular weight, soluble binding proteins that enhance ligand diffusion.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000502:physiology*; D002645:Chickens; D004058:Diffusion; D007413:Intestinal Mucosa / Q000378:metabolism*; D007700:Kinetics; D012710:Serum Albumin, Bovine / Q000494:pharmacology
D002135:Calcium-Binding Proteins; D012710:Serum Albumin, Bovine; D002118:Calcium