Related Experiment Video
Updated: Feb 11, 2026
Cell-Type Specific Protein Purification and Identification from Complex Tissues Using a Mutant Methionine tRNA Synthetase Mouse Line
Published on: April 13, 2022
[Isolation and crystallization of phenylalanyl-tRNA-synthetase from Thermus thermophilus HB8]
Abstract:
Method of isolation of phenylalanyl-tRNA synthetase from Thermus thermophilus HB8 is described, including chromatography on DEAE-sepharose, ammonium sulfate fractionation, hydrofobic chromatography on Toyopearl, gel filtration on ultrogel AcA-34, chromatography on phenylalanylaminohexyl-sepharose and heparine-sepharose. Yield of the purified enzyme was 10 mg from 1 kg of T. thermophilus cells. The enzyme is found to consist of two types of subunits with molecular masses 92 and 36 kDa and is likely to be a tetramer protein with molecular mass 250 kDa. Crystals of phenylalanyl-tRNA synthetase suitable for X-ray structural studies have been obtained.
Related Concept Videos
02:26tRNA Activation
02:26tRNA Activation
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
01:25Crystal Growth: Principles of Crystallization
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...