SCANNING ELECTRON-MICROSCOPY AND MOLECULAR MODELING OF INHIBITION OF CALCIUM-OXALATE MONOHYDRATE CRYSTAL-GROWTH BY CITRATE AND PHOSPHOCITRATE

Binding of citrate and phosphocitrate to calcium oxalate monohydrate c rystals has been studied using scanning electron microscopy (SEM) and molecular modeling. Phosphocitrate structure has been resolved using l ow temperature X-ray analysis and ab initio computational methods. The (-1 0 1) crystal surface of calcium oxalate monohydrate is involved i n binding of citrate and phosphocitrate, as shown by SEM and molecular modeling. Citrate and phosphocitrate conformations and binding energi es to (-1 0 1) faces have been obtained and compared to binding to ano ther set of calcium-rich planes (0 1 0). Difference in inhibitory prop erties of these compounds has been attributed to better coordination o f functional groups of phosphocitrate with calcium ions in (-1 0 1). R elevance of this study to design of new calcium oxalate monohydrate in hibitors is discussed.