Inhibition of Synthesis of Peroxidases and Some Proteins by Heliangine inPhaseolus mungoHypocotyl Sections

Abstract

The peroxidase activity in Phaseolus mungo hypocotyl sections floated on water decreased during the first 3 h and then increased again. The activity of this enzyme was reduced by heliangine and cyeloheximide in vivo, but not in vitro. Peroxidase activity is inhibited by heliangine and cycloheximide since the enzyme is not synthesized. Disk gel electrophoresis studies revealed that at least six species of proteins, soluble in Tris-HCl, pH 7.6, were synthesized in Phaseolus hypocotyl sections during 24 h incubation on water. Heliangine inhibited the synthesis of two of them, a species of peroxidase and another protein. Heliangine inhibited the incorporation of radioactive leucine into the cell wall fraction, suggesting that it inhibits synthesis of cell wall proteins. It did not, however, inhibit the incorporation of labelled proline into the cell wall fraction. The results suggest that heliangine inhibits the synthesis of only some proteins.