The influence of temperature on lysozyme crystals. Structure and dynamics of protein and water

Abstract

Lysozyme structures at six different temperatures in the range 95-295 K have been determined using X-ray crystallography at a resolution of 1.7 A. The crystals at lower temperatures had a 7.4% decrease in the unit-cell volume. The volume change was discontinuous with the volume being near 238 000 A, 3 from 295 to 250 K and about 220200 A 3 below 180 K. The thermal expansion of the protein has been analyzed and shows anisotropy, which is correlated with local atomic packing and secondarystructure elements. The lysozyme structure at low temperature is nearly the same as that at high temperature, with only small relative translations and rotations of structure elements including a hingebending rearrangement of two domains. Because of a considerable increase of lattice disorder at low temperature dynamical analysis of internal motion is difficult. The analysis of structural and dynamical properties of well ordered protein-bound water has been carried out.

Biomolecular cryocrystallography: Structural changes during flash-cooling

“…Accordingly, biomolecules are expected to unfold, not only at high temperature, but also at low temperature (5). In general, it is assumed that such cold denaturation is too slow to intervene during flash-cooling, and this assumption is corroborated by the finding that cryostructures usually differ little from the corresponding room-temperature structures (6)(7)(8)(9). Indeed, in a comparison of 15 protein structures determined both at cryogenic and room temperature, the rms deviation of nonhydrogen backbone atoms in the optimally superimposed structures was only 0.2-0.8 Å (9).…”

“…This fact is probably widely appreciated within the crystallography community, although rarely stated explicitly. With a few notable exceptions (6)(7)(8)(9)(10)(11)(12), it is usually taken for granted that the cryostructure is quenched at ambient temperature (T* ϭ T 0 in our notation) and, therefore, that the only structural effect of the low temperature is to sharpen the atomic displacement distributions without significantly displacing the mean atomic positions [apart from a more-or-less uniform contraction of the protein (6-9)]. In contrast to this conventional wisdom, the present analysis indicates that many degrees of freedom are quenched at temperatures near 200 K, where local conformational and association equilibria may be strongly shifted toward low-enthalpy states.…”

High-Resolution Structure (1.33 Å) of a HEW Lysozyme Tetragonal Crystal Grown in the APCF Apparatus. Data and Structural Comparison with a Crystal Grown under Microgravity from SpaceHab-01 Mission

“…It was thus possible to make a calibration of the X-ray properties of ground-grown crystals to compare them with spacegrown ones using identical conditions except the level of gravity. The reasons for the choice of hen egg-white lysozyme as a model protein were multiple: the structure of lysozyme is known at high resolution (Madhusudan, Kodandapani & Vijayan, 1993;Harata, 1994;Pike & Acharya, 1994;Kurinov & Harrison, 1995), it is easily available in gram quantities, it crystallizes in a time span compatible with the duration of a US Shuttle flight, its phase diagram on earth is known at various temperatures (Ataka & Asai, 1988;Howard, Twigg, Baird & Meehan, 1988;Guilloteau, Ri~s-Kautt & Ducruix, 1992), and it is one of the most extensively studied proteins in crystallogenesis (Feher & Kam, 1985;Ataka & Asai, 1988;Ri~s-Kautt & Ducruix, 1989;Mikol, Hirsch & Giegr, 1990;DeMattei & Feigelson, 1992;Monaco & Rosenberger, 1993;Forsythe & Pusey, 1994).…”

Temperature-dependent macromolecular X-ray crystallography

“…Subsequently, several other protein structures have been studied at more temperature points and in a broader temperature range from 80 to 300 K (Singh et al, 1980;Hartmann et al, 1982;Parak et al, 1987;Tilton et al, 1992;Kurinov & Harrison, 1995;Nagata et al, 1996;Teeter et al, 2001;Joti et al, 2002;Edayathumangalam & Luger, 2005;Schmidt et al, 2009;Kim et al, 2009). Crystallographic B factors (Debye-Waller factors) can also provide some insights into protein dynamics.…”