CRYSTAL-GROWTH AND MOLECULAR MODELING STUDIES OF INHIBITION OF STRUVITE BY PHOSPHOCITRATE

The inhibition by phosphocitrate of struvite crystal formation and gro wth has been examined in the present study. Crystal growth in a gel ma trix was controlled by phosphocitrate in a dose-dependent manner. The effects of inhibition were followed using scanning electron microscopy , optical microscopy, and single crystal X-ray analysis. The presence of phosphocitrate induced very strong, crystal face specific inhibitio n of struvite, leading to total cessation of crystal growth when suffi cient concentration of the inhibitor was made available. Crystal growt h studies and results from molecular modeling indicated strong affinit y of phosphocitrate to (101) faces of struvite. This in turn led to an alteration in the expression of these faces and the development of a characteristic arrowhead struvite morphology. Similar changes were not observed in the presence of identical concentrations of citrate, acet ohydroxamic acid, and N-sulfo-2 amino tricarballylate (an analog of ph osphocitrate), emphasizing the unique interaction of phosphocitrate wi th the struvite crystal lattice.