Control of calcium oxalate crystal growth by face-specific adsorption of an osteopontin phosphopeptide.

摘要: Mineral-associated proteins have been proposed to regulate many aspects of biomineralization, including the location, type, orientation, shape, and texture crystals. To understand how achieve this exquisite level control, we are studying interaction between phosphoprotein osteopontin (OPN) biomineral calcium oxalate monohydrate (COM). In present study, synthesized peptides corresponding amino acids 220-235 rat bone OPN (pSHEpSTEQSDAIDpSAEK), one several highly phosphorylated, aspartic-, glutamic acid-rich sequences found in protein. investigate role phosphorylation with crystals, containing no (P0), (P1), or all three (P3) phosphates were prepared. Using a novel combination confocal microscopy scanning electron microscopy, show that these adsorb preferentially {100} faces COM inhibit growth phosphorylation-dependent manner. characterize mechanism adsorption COM, performed first atomic-scale molecular-dynamics simulation protein-crystal interaction. P3 adsorbs face much more rapidly than P1, which turn P0. cases, aspartic acid, not phosphoserine, closest contact crystal surface. These studies identified face-specific motif delineated separate roles for carboxylate phosphate groups inhibition by mineral-associated phosphoproteins. We propose formation close-range, stable, interactions is key factor ability phosphoproteins biomineralization processes.