Effects of serum, albumin and immunoglobulins on urease-induced crystallization in urine.

The effects of serum, albumin and gammaglobulins on urease-induced crystallization have been studied in synthetic and in human urine. Serum and the studied proteins increased urease enzymatic activity in synthetic urine. In human urine only serum had this effect. In synthetic urine, the proteins and serum markedly decreased the precipitation attached to glass surfaces, while the intraluminal precipitation was increased. In human urine, similar but weaker effects on the precipitation were found for serum and albumin. These findings suggest that the proteins studied, in the concentrations in which they are present in human urine, have profound effects on urease-induced crystallization and may be physiological crystallization inhibitors.