Reversible inhibition of calcium oxalate monohydrate growth by an osteopontin phosphopeptide.

Calcium oxalate, primarily as calcium oxalate monohydrate (COM), is the primary constituent of most kidney stones. Certain proteins, such as osteopontin (OPN), inhibit stone formation. The complexity of stone formation and the effects of urinary proteins at various stages of the process make it hard to predict the exact physiological roles of these proteins in growth inhibition.