Exploring the Modulatory Effect of Albumin on Calcium Phosphate Crystallization

Urolithiasis, also known as renal lithiasis, is a commonly occurring disease in humans. Calculi are formed in the urinary tract, including the tubular region of the kidney. Calcium phosphate crystals, especially hydroxyapatite, are responsible for nidus formation in the more commonly occurring calcium oxalate kidney stones. In the present study, effect of different concentrations of human serum albumin on nucleation, growth and demineralization of calcium phosphate crystallization using growth assay system and its confirmation with in silico study have been analysed. Human serum albumin shows inhibitory effect on nucleation, while it shows both stimulatory as well as inhibitory activity on the growth of calcium phosphate crystals. The results suggest that albumin plays a role in both inhibition as well as promotion of calcium phosphate crystallization. The in silico study indicates involvement of Tyr-161, Arg-222 and Lys- 195 and Lys-199 residues of albumin with calcium phosphate crystal.