The biochemistry and physiology of metallic fluoride: action, mechanism, and implications.
Fluoride is a well-known G protein activator. Activation of heterotrimeric GTP-binding proteins by fluoride requires trace amounts of Al3+ or Be2+ ions. AlFx mimics a gamma-phosphate at its transition state in a Galpha protein and is therefore able to inhibit its GTPase activity. AlFx also forms complexes with small GTP-binding proteins in the presence of their GTPase-activating proteins (GAP). As phosphate analogs, AlFx or BeFx affect the activity of a variety of phosphoryl transfer enzymes. Most of these enzymes are fundamentally important in cell signal transduction or energy metabolism. Al3+ and F- tend to form stable complexes in aqueous solution. The exact structure and concentration of AlFx depend on the pH and the amount of F- and Al3+ in the solution. Humans are exposed to both F and Al. It is possible that Al-F complexes may be formed in vivo, or formed in vitro prior to their intake by humans. Al-F complexes may play physiological or pathological roles in bone biology, fluorosis, neurotoxicity, and oral diseases such as dental caries and periodontal disease. The aim of this review is to discuss the basic chemical, biochemical, and toxicological properties of metallic fluoride, to explore its potential physiological and clinical implications.
Li
Liang
L
Faculty of Dentistry, University of Manitoba, Winnipeg, MB, Canada. umlil@cc.umanitoba.ca
D017607:Aluminum Compounds / Q000737:chemistry* / Q000378:metabolism* / Q000633:toxicity; D000565:Ameloblasts / Q000187:drug effects; D000818:Animals; D025243:Bacterial Proton-Translocating ATPases / Q000037:antagonists & inhibitors; D001608:Beryllium / Q000737:chemistry / Q000502:physiology / Q000633:toxicity; D001682:Biological Availability; D001842:Bone and Bones / Q000187:drug effects; D005459:Fluorides / Q000737:chemistry* / Q000378:metabolism* / Q000633:toxicity; D009050:Fluorosis, Dental / Q000209:etiology; D020558:GTP Phosphohydrolases / Q000037:antagonists & inhibitors; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D009498:Neurotoxins; D010770:Phosphotransferases / Q000037:antagonists & inhibitors; D015398:Signal Transduction
D017607:Aluminum Compounds; D009498:Neurotoxins; C035982:beryllium fluoride; D010770:Phosphotransferases; D025243:Bacterial Proton-Translocating ATPases; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D001608:Beryllium; D005459:Fluorides; C032311:aluminum fluoride