Lysozyme, diffraction

PL Howell, SC Almo, MR Parsons, I Hajdu, GA Petsko. Stiaicture determination of turkey egg-white lysozyme using Laue diffraction data. Acta Crystallogr B, 48 200-207, 1992. 

Because 0-acyl chitins appear to be scarcely susceptible to lysozyme, the susceptibility of DBG to Upases has been studied to obtain insight into its biodegradability in vivo. The changes in infrared and X-ray diffraction spectra of the fibers support the slow degradation of DBG by Upases [125,126]. The chemical hydrolysis of DBG to chitin is the most recent way to produce regenerated chitin. 

The successful use of these X-ray crysallographic techniques in studying the enzyme-substrate interactions of lysozyme (21) and chymotrypsin (22) has recently been reviewed by Blow and Steitz (16) and Blow (23). To date, however, these methods have had only limited application, since the detailed structures of only about ten enzymes have been elucidated by X-ray diffraction... 

Since use of increasing amounts of cosolvents as antifreeze could perturb the conformation and thus the activity of lysozyme, a number of experiments were carried out to try to determine conditions for investigating lysozyme reactions and lysozyme-substrate intermediates in cooled mixed solvents as a preliminary to similar investigation by X-ray diffraction on crystals. Work began with an estimate of the solubility of... 

Harada, Y., Lifchitz, A., Berthou, J., and JoUes, P. (1981) A translation function combining packing and diffraction information an apphcation to lysozyme (high-temperature form). Acta Crystallogr. A 37,398-406. 

The first protein structure to be learned was that of myoglobin, which was established by Kendrew et al. in I960.391-393 That of the enzyme lysozyme was deduced by Blake et al. in 1965.394 Since then, new structures have appeared at an accelerating rate so that today we know the detailed architecture of over 6000 different proteins395 with about 300 distinctly different folding patterns 396 New structures are being determined at the rate of about one per day. X-ray diffraction has also been very important to the study of naturally or artifically oriented fibrous proteins397 and provided the first experimental indications of the P structure of proteins. 

Its role is to cut a hole in the bacterial cell wall to permit injection of the virus own DNA. Egg white lysozyme, the first enzyme for which a complete three-dimensional structure was determined by X-ray diffraction,55 is a 129-residue protein. 

The X-ray diffraction experiment on the lysozyme-inhibitor complex40 is a well-known example which gave evidence for the transition state complementarity. 

In this study [15,29], we have carried out the 3D-RISM calculation for a hen egg-white lysozyme immersed in water and obtained the 3D-distribution function of oxygen and hydrogen of water molecules around and inside the protein. The native 3D structure of the protein is taken from the protein data bank (PDB). The protein is known to have a cavity composed of the residues from Y53 to 158 and from A82 to S91, in which four water molecules have been determined by means of the X-ray diffraction measurement [30]. In our calculation, those water molecules are not included explicitly. 

Table 19.8. °Io H/D exchange in lysozyme in the crystalline state (neutron diffraction) and in solution (NMR measured after 6 weeks) [641]...

The three-dimendrmal structure of many enzyme molecules, including hydrolytic enzymes such as lysozyme, clymotiypsin, tibonudease, carboxypeptidase A, elastase, and papain, has been determined in recent years through the X-ray diffraction method, and the steric arrangement and function of amino add residues at the active site has been elucidated (i). 

Poole et al. (1987) measured powder diffraction for lysozyme samples of varied hydration. Diffraction of ice crystallites was first detected at hydration levels greater than 0.3 h. The point of first appearance of frozen water is also defined by the shift and growth of the O—D stretch band in infrared spectra measured for protein samples variously hydrated with deuterated solvent (Finney et al., 1982). 

Table II compares determinations of the nonfreezing water of lysozyme, measured by scanning calorimetry, NMR, infrared spectroscopy, and X-ray diffraction.

Blake et al. (1983) refined the structures of human lysozyme (HL) and tortoise egg white lysozyme (TEWL) to 1.5 and 1.6 A resolution, respectively. The diffraction was modeled as arising from three components the protein, ordered water, and disordered water. Most of the water in the crystals (i.e., 60—80%) is disordered. The analysis located 143 molecules of ordered water out of about 350 per HL molecule, and 122 molecules out of 650 per TEWL molecule. The ordered water covers 75% of the available surface of the the protein. One-third (TEWL) to one-half (HL) of the total surface is unavailable for analysis of the adjacent water, owing to crystal contacts or disorder in the protein region. Thus, the estimate of surface coverage is in good agreement with the 300 molecules of water estimated by heat capacity measurements as full hydration (0.38 h). The area covered per water molecule is estimated as 18.9... 

Kundrot and Richards (1987, 1988) described the solvation shell in the hen egg white lysozyme crystal, in connection with a study of the compressibility of protein and solvent. Mason et al. (1984) carried out a neutron diffraction analysis of triclinic lysozyme at 1.4 A resolution, with 239 water molecules included in the refinement. 

Kachalova et al. (1987) measured the effect of dehydration on the diffraction of three crystal forms of lysozyme, at 3 or 6 A resolution. The lowest relative humidity studied was 0.4. The molecules as a whole were displaced on dehydration by 1.9-5.2 A, through rotation and translation of the units. There was also displacement of the two domains of lysozyme relative to one another. The domain displacements of 1.4-... 

The crystallographic results of Blake et al. (1983), who analyzed high-resolution X-ray diffraction data for human lysozyme (HL) and tortoise egg white lysozyme (TEWL) fit the above picture. The crystallographic... 

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