DIRECT DETERMINATION OF DENSITY AND
LOCATION OF WATER ASSOCIATED WITH
TRANSFER RNA AND OF THE CONFORMATION
OF THE MACROMOLECULE AS A FUNCTION OF
SALT IN THE SOLUTION
G. Zaccai
To cite this version:
G. Zaccai. DIRECT DETERMINATION OF DENSITY AND LOCATION OF WATER ASSOCIATED WITH TRANSFER RNA AND OF THE CONFORMATION OF THE MACROMOLECULE AS A FUNCTION OF SALT IN THE SOLUTION. Journal de Physique Colloques, 1984, 45 (C7), pp.C7-265-C7-265. <10.1051/jphyscol:1984731>. <jpa-00224296>
HAL Id: jpa-00224296
https://hal.archives-ouvertes.fr/jpa-00224296
Submitted on 1 Jan 1984
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JOURNAL DE PHYSIQUE
Colloque C7,suppl6ment au n09, Tome 45, septembre 1984
page C7-265
DIRECT DETERMINATION OF DENSITY AND LOCATION OF WATER ASSOCIATED WITH
TRANSFER RNA AND OF THE CONFORMATION OF THE MACROMOLECULE AS A
FUNCTION OF SALT IN THE SOLUTION
G. Zaccai
I n s t i t u t Max von Laue-PauZ Langevin, 156 X , 38042 GrenobZe Cedex, Frmee
By using a contrast variation approach in small angle neutron scattering experiments,
A ~characterised
~ ~
quantitatively by its
the microenvironment around yeast ~ R N was
excess density over bulk solvent and radius of gyration about the centre of mass of
the macromolecule. The radius of gyration of the macromolecule alone was also
determined. Experiments were performed in a number of different salt conditions.
In NaCl and KC1 solutions between 0.1 M and 1 M, the conformation of the tRNA
macromolecule is similar to that observed in single crystal X-ray studies. The
microenvironment, on the other hand, varies in its structure both with the nature
of the salt and its concentration. This work is described in detail by Li et al,,
Biochemistry,
4380-4388, 1983. In solutions of N(CH3)4C1
(TMA.Cl), the tRNA
macromolecule remains in an extended conformation, similar to its low salt
structure, in the entire concentration range studied (up to 2M TMA.Cl).
When
TPJA.Cl is mixed with NaCl or MaC12, there is competition between the different
cations to "structure" the macromolecule (Xian and Zaccai, manuscript in preparation).
2,
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1984731