Plasminogen phenotypes in a Japanese population. Four new variants including one with a functional defect.

Human plasminogen (PLG) phenotypes were investigated by polyacrylamide gel isoelectric focusing followed by immunoblotting. In 5,735 plasma samples from unrelated, healthy Japanese individuals, four new variants were detected and tentatively designated PLG AOsaka, PLG BOsaka, PLG MOsaka and PLG ANara. The plasminogen concentrations and activities of the PLG phenotypes were studied. In agreement with previous studies PLG M5 was found to have a decreased activity. The new variant PLG MOsaka had a very low activity and appears to be an abnormal plasminogen with a functional defect similar to that of PLG M5.