title: Inhibition of calcium pyrophosphate dihydrate crystal formation: effects of carboxylate ions.
abstract: Proteoglycans are recognized to inhibit calcium pyrophosphate dihydrate (CPPD) crystal formation but the mechanisms are not known. To study the role of carboxylate (-CO2-) ligands, the possible inhibitor effects of sodium acetate, sodium D-glucuronate, disodium malate, and trisodium citrate were studied using solution mixtures containing [Ca2+] = 1.5 mM, [Mg2+] = 0.5 mM, [PPi] = 0.1 mM, [Pi] = 0.1 mM, [Na+] = 140 mM, 37 degrees C, pH 7.4 with or without 9.5 +/- 0.5 mg CPPD (seed) crystals. These studies showed that monocarboxylates (acetate, glucuronate) have little inhibitive effect. Progressively greater inhibition was found with dicarboxylate (malate) and tricarboxylate (citrate) indicating that the arrangement of carboxylate (and sulfate) ligands on proteoglycan is more important than the inhibitory effect of individual ligands.
authors.affiliation: Department of Pathology, Mount Sinai Hospital, University of Toronto, Canada.
authors.forename: P T
authors.initials: PT
authors.lastname: Cheng
authors.forename: K P
authors.initials: KP
authors.lastname: Pritzker
mesh_terms: D002118:Calcium / Q000032:analysis; D002131:Calcium Pyrophosphate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002264:Carboxylic Acids / Q000494:pharmacology*; D003460:Crystallization; D011756:Diphosphates / Q000378:metabolism*; D007477:Ions; D008024:Ligands; D011509:Proteoglycans / Q000494:pharmacology
chemical_list: D002264:Carboxylic Acids; D011756:Diphosphates; D007477:Ions; D008024:Ligands; D011509:Proteoglycans; D002118:Calcium; D002131:Calcium Pyrophosphate