Jp. Bouquiere et al., INTERACTION OF THE TETRAMETHYLAMMONIUM ION WITH THE LYSOZYME MOLECULE, STUDIED USING NEUTRON-DIFFRACTION, Journal of the Chemical Society. Faraday transactions, 89(15), 1993, pp. 2701-2705
Citations number
10
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Using single-crystal neutron diffraction, the interaction between the
deuteriated tetramethylammonium (TMA) ion and the surface of lysozyme
has been studied, in triclinic crystals of hen egg-white lysozyme soak
ed in a 30% volume concentration of TMACI. Four partially occupied TMA
sites were located, and refined to a final crystallographic R factor
of 0.135. Although the average B factor of the TMA-soaked lysozyme was
higher than in the unsoaked crystals, no correlation between enhanced
(or reduced) B factors and the TMA positions was found. There were al
so no significant differences induced in the protein conformation. The
close environment of the TMA positions was found to be predominantly
polar, in contrast to earlier related studies of the interactions of l
ysozyme with ethanol and DMSO, where the environment was found to be p
redominantly non-polar. That the last two molecules act as protein den
aturants, while TMA has protectant properties, raises interesting issu
es covering the mechanisms of the stabilisation and destabilisation of
protein structures that warrant further study.