Conformation of egg-white model

Fig. 3. Perspective drawing of the main-chain conformation of domestic hen egg-white lysozyme. The view is an elevation from the active-site side of the molecule (Imoto et al., 1972). Only the positions of the a-carbon atoms are shown. An instructive colored painting by I. Geis of the original three-dimensional model of lysozyme is reproduced in the early review by Phillips (1966). Of historic interest is the drawing of the model by the late Sir Lawrence Bragg (reproduced by Blake et al., 1965, and Phillips et al., 1987). It is to be noted that Bragg s diagram is a free-hand drawing and not an accurate computer-generated representation of the molecule. (Reproduced with permission from Imoto et al., 1972.)...

The partial molar volume is a thermodynamic quantity that plays an essential role in the analysis of pressure effects on chemical reactions, reaction rate as well as chemical equilibrium in solution. In the field of biophysics, the pressure-induced denaturation of protein molecules has continuously been investigated since an egg white gel was observed under the pressure of 7000 atmospheres [60]. The partial molar volume is a key quantity in analyzing such pressure effects on protein conformations When the pressure in increased, a change of the protein conformation is promoted in the direction that the partial molar volume reduces. A considerable amount of experimental work has been devoted to measuring the partial molar volume of a variety of solutes in many different solvents. However, analysis and interpretation of the experimental data are in many cases based on drastically simplified models of solution or on speculations without physical ground, even for the simplest solutes such as alkali-halide ions in aqueous solution. Matters become more serious when protein molecules featuring complicated conformations are considered. 

The hydration dependence studies of the internal protein dynamics of hen egg white lysozyme by and H NMR relaxation have been presented. The relaxation times were quantitatively analysed by the well-established correlation function formalism and model-free approach. The obtained data was described by a model based on three types of motion having correlation times around 10 , 10 and 10 s. The slowest process was shown to originate from correlated conformational transitions between different energy minima. The intermediate process was attributed to librations within one energy minimum, and the fastest one was identified as a fast rotation of methyl protons around the symmetry axis of methyl groups. A comparison of the dynamic behaviour of lysozyme and polylysine obtained from a previous study revealed that in the dry state both biopolymers are rigid on both fast and slow time scales. Upon hydration, lysozyme and polylysine showed a considerable enhancement of the internal mobility. The side chain fragments of polylysine were more mobile than those of lysozyme, whereas the backbone of lysozyme was found to be more mobile than that of polylysine. 

Details of the conformation of the triclinical form of hen egg-white lysozyme have been reported the triclinical and tetragonal crystal forms were compared using appropriately weighted difference maps at 2.5 A resolution. Another model of the triclinical structure was obtained using a real-space refinement procedure. Differences between the conformations of the two forms occur at regions on the surface involved in intermolecular contacts. Regeneration of the enzymic activity of the reduced peptide 1-127 from hen egg-white lysozyme... 

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