Enhancement in the perfection of orthorhombic lysozyme crystals grown in ahigh magnetic field (10 T)

Citation
T. Sato et al., Enhancement in the perfection of orthorhombic lysozyme crystals grown in ahigh magnetic field (10 T), ACT CRYST D, 56, 2000, pp. 1079-1083
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis
Journal title
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
ISSN journal
0907-4449 → ACNP
Volume
56
Year of publication
2000
Part
8
Pages
1079 - 1083
Database
ISI
SICI code
0907-4449(200008)56:<1079:EITPOO>2.0.ZU;2-0
Abstract
Orthorhombic crystals of hen egg-white (HEW) lysozyme were grown in a homog eneous and static magnetic field of 10 T. All crystals grown at 10 T were o riented such that their crystallographic c axes were parallel to the magnet ic field direction and showed a narrower average full-width at half-maximum (FWHM) of the rocking curve than those grown at 0 T. Rocking-width measure ments were made at the BL-10A station at the Photon Factory, Tsukuba, Japan , using a high-resolution vertical-type four-circle diffractometer. Crystal perfection was evaluated using the FWHM of the rocking curve; the effects of the magnetic field on the quality of the crystals were examined by compa rison of the FWHM of seven crystals grown at 10 and 0 T. The FWHMs of the r eflections along the a, b and c axes decreased by 23.5, 35.3 and 27.8%, res pectively, and those of other general reflections decreased by 17.4-42.2% i n the crystals grown at high magnetic field. These results clearly showed t hat a magnetic field of 10 T improved the crystal perfection of the orthorh ombic lysozyme crystals. As a result, the maximum resolution of X-ray diffr action increased from 1.3 Angstrom at 0 T to 1.13 Angstrom at 10 T. The mag netic field also affected the dimensions of the unit cell, increments being 0.2% for the a and c axes and 0.1% for the b axis, respectively. These fac ts suggest that the application of a high magnetic field during crystalliza tion might result in remarkable enhancements in the diffraction power of pr otein crystals having magnetic anisotropy.