Joseph E. Fuhr

Translational control of globin synthesis by low molecular weight RNA

Summary A species of low molecular weight RNA implicated in the translational control of protein synthesis was analyzed for heterogeneity on Dowex-1 columns. Highest apparent purity was associated with preparations obtained from the high salt wash of ribosomes, and which were subsequently further purified by ethanol precipitation. Kinetic analyses indicated the RNA was not capable of blocking the formation of an inhibitor in the lysate system. Addition of the RNA preparation stimulated the synthesis of all three globin chains by a lysate prepared from cord blood reticulocytes.

Protection by cycloheximide from hyperthermic inhibition of protein synthesis in human reticulocytes.

Abstract Heat shock produced an irreversible inhibition in vitro of hemoglobin synthesis in human reticulocytes. The higher the temperature and the longer the cells were exposed to elevated temperature the greater was the inhibition. Hyperthermic inhibition was significantly decreased when translation was inhibited by cycloheximide before and during heat shock. The longer the cells were exposed to cycloheximide before heat shock, the greater was the subsequent level of protein synthesis following heat shock. On the basis of studies with isonicotinic acid hydrazide, at least part of the protective effect appears to be due to an accumulation of heme.

Evaluation of commercial erythropoietin activity after preparative isoelectric focusing

Abstract The in vitro study of erythropoiesis is often hampered by impurities associated with commerical preparations of erythropoietin. This report describes the activities associated with commercial erythropoietin, as well as a rapid and convenient method, preparative isoelectric focusing, to enhance the purity of low specific activity erythropoietin preparations.