Role of a protein inhibitor isolated from human renal stone matrix in urolithiasis.

The role of biomolecule(s) from renal stone matrix in urolithiasis was investigated. The ability of a particular fraction (> 10 kDa fraction) isolated from the EDTA extract of powdered human renal stones to influence calcium oxalate monohydrate (COM) crystal growth was studied. The most potent inhibitor of COM crystal growth obtained from > 10 kDa fraction was purified by various chromatographic techniques and SDS-PAGE, etc. and was found to have a molecular mass of 36 kDa. The urine and serum samples obtained from normal persons were found to be more potent in inhibiting the growth of COM crystals as compared to the kidney-stone patients. Polyclonal antibodies were raised against this inhibitor and were employed to determine the concentration of 36 kDa inhibitor in urine and serum samples of normal persons and kidney-stone patients.