title: Hydrostatic pressure effects on protein synthesis.
abstract: The effects of high hydrostatic pressure on several phases of cell-free protein synthesis have been examined. The initial rate of polyuridylic acid (poly U)-directed synthesis of polyphenylalanine showed an apparent increase at 100 atm, above which the synthetic rate was reduced sharply with increased pressure up to 640 atm where 95% inhibition was observed. The magnitude of the inhibition of polyphenylalanine synthesis with increased pressure depended strongly on the magnesium salt concentration in the reaction system. Misreading of the poly U message, as measured by insertion of leucine in place of phenylalanine, dropped rapidly with increased pressure from 1 to 350 atm, above which the amount of misreading increased. Enzymatic activation of transfer RNAs (tRNAs) was reduced by increased pressure in the range 100-640 atm, where the rate of tRNA aminoacylation was 80% inhibited. Both nonenzymatic attachment of phenylalanyl-tRNA (phe-tRNA) to the poly U-ribosome complex and stability of the phe-tRNA-poly U-ribosome complex were decreased at high pressures (100-900 atm). The results of the action of pressure on the various phases of cell-free protein synthesis suggest that the major pressure-sensitive element in the protein synthetic machinery is the ribosome.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases; D001426:Bacterial Proteins / Q000096:biosynthesis*; D002247:Carbon Isotopes; D002474:Cell-Free System; D004355:Drug Stability; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D010649:Phenylalanine / Q000378:metabolism; D011072:Poly U / Q000494:pharmacology; D011312:Pressure; D012329:RNA, Bacterial; D012343:RNA, Transfer / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014316:Tritium
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D012329:RNA, Bacterial; D014316:Tritium; D011072:Poly U; D010649:Phenylalanine; D012343:RNA, Transfer; D000604:Amino Acyl-tRNA Synthetases; D007930:Leucine; D008274:Magnesium