SOME MOLECULAR CHARACTERISTICS OF ERYTHROPOIETIN FROM DIFFERENT SOURCES DETERMINED BY INACTIVATION BY IONIZING RADIATION

Abstract

A crude, urine-derived, erythropoietin-containing preparation was subjected to inactivation by high energy electrons and low energy X-rays. The molecular weight was calculated to be about 27,000 by using the "target theory" computations of Lea. Inactivation characteristics to low energy X-rays suggest that the molecule is asymmetric and is about ten times as long as it is wide. The result of irradiation of erythropoiesis-stimulating material from renal and cerebellar hemangioblastoma cysts from patients with polycythemia suggests that the biologically active molecule from these sources has the same or nearly the same size as that derived from urine of an anemic patient.