[Purification and properties of phenylalanyl-tRNA-synthetase from Escherichia coli MRE-600].
A preparative scale method for isolation of highly purified phenylalanyl-tRNA synthetase from E. coli MRE-600 was developed. It consists of cell destroying, nucleic acid precipitation with streptomycine sulfate, fractionation with ammonium sulfate followed by chromatography on different carriers (Sephadex G-200, DEAE-cellulose, DEAE-Sephadex A-50, and hydroxyapatite). The mode of cell destroying was found to affect the process of the further enzyme purification. The phenylalanyl-tRNA synthetase was purified 540-fold, with recovery being 20.6% and the specific activity - 540 units per mg protein. The enzyme content in the purified preparation was 80-90% judging by electrophoresis in PAAG. The molecular weights of the subunits determined by electrophoresis under denaturative conditions were found to be 102,000 +/- 4000 (beta) and 42,000 +/- 2000 (alpha). The molecular weight of the native enzyme determined by gel filtration through Sephadex G-200 and electrophoresis at varied concentrations of polyacrylamide was found to be 340,000 +/- 20,000. The Km values for tRNA, ATP and phenylalanine in the aminoacylation reaction are equal to 5.4 X 10(-7) M, 1,9 X 10(-4) M, and 3.7 X 10(-6) M, respectively.
D000604:Amino Acyl-tRNA Synthetases / Q000302:isolation & purification*; D002848:Chromatography, DEAE-Cellulose / Q000379:methods; D002850:Chromatography, Gel / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004926:Escherichia coli / Q000201:enzymology*; D008970:Molecular Weight; D010652:Phenylalanine-tRNA Ligase / Q000032:analysis / Q000302:isolation & purification*; D013056:Spectrophotometry, Ultraviolet
D000604:Amino Acyl-tRNA Synthetases; D010652:Phenylalanine-tRNA Ligase
Ochistka i nekotorye svoĭstva fenilalanil-tRNK-sintetazy iz Escherichia coli MRE-600.