Isolation of a mucoprotein possessing mineral nucleating activity.

We isolated a mucoprotein from the urine of stone-formers that promotes the precipitation of oxalate. The mucoprotein has a molecular weight of 51,000 daltons and an isolectric point of 2.8. Although its hexuronic and stalic acid content is quite small, its glycine (31.3 per cent) and glutamic acid (12.2 per cent) content is high.