Factors determining the aggregation of urinary mucoprotein.

The factors determining aggregation of Tamm-Horsfall urinary mucoprotein have been examined using the technique of light-scattering photometry, which has allowed the study to be performed at the concentrations of the mucoprotein in which it occurs in the urine in vivo. The tendency to formation of aggregates is enhanced by increases in concentration of the mucoprotein, by increases in electrolyte concentration within physiological limits, and by lowering of the pH within the physiological range. The effects of 1:2 and 2:1 electrolytes are somewhat different from those of 1:1 electrolytes. The data suggest that the isoelectric point of Tamm-Horsfall protein is higher than previously thought.