More evidence for a particle character of aminoacyl-transfer RNA synthetases isolated from rat liver

Glutaminyl-, isoleucyl-, leucyl-, lysyl- and methionyl-transfer RNA synthetase can be isolated from a postmicrosomal fraction from rat liver as a complex which resists separation in the following techniques: gel filtration on Sephadex G200, chromatography on DEAE-Sephadex A50, chromatography on DEAE-Sephadex A50, chromatography on hydroxyapatite, centrifugation in sucrose gradients and isoelectric focusing. The complex has a sedimentation coefficient of 18 s. In the electron microscope it appears as an organized structure of well-defined size and shape. These observations might provide additional evidence for the particle character of aminoacyl-transfer RNA synthetases.