Lysozymes, calcium binding

Malisauskas, M., Zamotin, V.,Jass, J., Noppe, W., Dobson, C. M., and Morozova-Roche, L. A. (2003). Amyloid protofilaments from the calcium-binding protein equine lysozyme Formation of ring and linear structures depends on pH and metal ion concentration. / Mol. Biol. 330, 879-890. 

Cytochrome c peroxidase domain 1 C. Miscellaneous antiparallel a Carp muscle calcium-binding protein Egg lysozyme Citrate synthase Catalase domain 2 Cytochrome c peroxidase domain 2 p-Hydroxybenzoate hydroxylase domain 3 II. Parallel a/j3 domains... 

Tufty) r M., and Kretsinger, R. H. Troponin and parvalbumin calcium binding regions predicted in myosin light chain and T4 lysozyme. Science 187,167-169 (1975). 

Fig. 10.T. Selective ion binding by human lysozyme upper left, wild type upper middle, Q86D upper right, A92D lower left, Q86D/A92D. The lower middle picture shows the calcium binding site in the Q86D/A92D mutant detected by X-ray, while the picture in lower right exhibits the binding-site found by the 3D-RISM theory...

Figure 4 The electrostatic distributions of a-lactalbumin (lALC) (a) and chicken egg-white lysozyme (ILZl) (b) calculated by Delphi and presented by Grasp. Both surfaces of calcium-binding protein a-lactalbumin are mostly negatively charged (a) (in red) while the surfaces of noncalcium binding protein lysozyme (b) are mostly positively charged (in blue)...

Ile-27, runs to Asp-88, and is partially occupied by water molecules. The channel is blocked by Tyr-103 (which is in the cleft region). There are corresponding cavities in hen egg-white lysozyme. The second cavity in the vicinity of Ser-91 is occupied by internal water molecules in egg-white lysozyme. This residue becomes Asp (residue 88) in a-lactalbumin. Due to calcium binding properties in a-lactalbumin, the locations of internal water molecules are somewhat different from those in lysozymes that do not bind calcium. 

Some 13 years after Carr s original observations, Kretsinger (1976), in his review of calcium-binding proteins, assumed that lysozyme can attach Ca(ll), as well as other cations. It was not until 1981 that binding of Ca(Il) to lysozyme was further studied. Imoto et al. (1981) determined the stability (association) constant (40 M" ) and found that lysozyme is inhibited in the presence of Ca(II), showing only 26% of the activity of the free enzyme toward hexa-AT-acetylglucosamine. Because of this inhibition, they predicted that Ca(II) binds near the catalytic carboxyls. Furthermore, Ca(II) shifts the native-denatured transition in lysozyme toward the native state, and thus has some preservative effect on the protein. 

At the same time the precise delineation of the calcium binding site, discussed in Section VII (see also Table IX and Fig. 8), naturally led to the consideration of the minimum number of these residues that must be present and the relevant conformation of the peptide chain to enable calcium binding to occur. Questions that arise immediately are Can any lysozyme bind Ca(II) in a comparable manner To what extent can lysozymes exhibit weak lactose synthase activity and a-lactalbumins exhibit weak lytic activity ... 

Makin OS, Serpell LC (2005) Structures for amyloid fibrils. FEBS J 272 5950-5961 Malinchik SB, Inouye H, Szumowski KE, Kirschner DA (1998) Structural analysis of Alzheimer s beta(l O) amyloid protofilament assembly of tubular fibrils. Biophys J 74 537-545 Malisauskas M, Zamotin V, Jass J, Noppe W, Dobson CM, Morozova-Roche LA (2003) Amyloid protofilaments from the calcium-binding protein equine lysozyme formation of ring and linear structures depends on pH and metal ion concentration. J Mol Biol 330 879-890 Mantuano E, Veneziano L, Jodice C, ErontaU M (2003) Spinocerebellar ataxia type 6 and episodic ataxia type 2 differences and similarities between two allelic disorders. Cytogenet Genome Res 100 147-153 Markesbery WR(1997) Oxidative stress hypothesis in Alzheimer s disease. Free Radic Biol Med 23 134-147 Marks MS, Seabra MC (2001) The melanosome membrane dynamics in black and white. Nat Rev Mol Cell Biol 2 738-748... 

The calcium-binding milk protein a-lactalbumin and lysozyme from hen egg white show very different VCD spectra, though X-ray analysis reveals that the three-dimensional structures in the crystalline state are very similar. If one adds propanol to an aqueous solution of a-lactalbumin, the helical regions become enlarged and the spectra become similar. 

Fig. 3.13. Proportionality of the loss of accessible surface area to the molecular weight of proteins (from Janin, 1976). Different proteins insulin, rubredoxin, pancreatic trypsin inhibitor, HIPIP, calcium binding protein, ribonuclease S, lysozyme, staphylococcal nuclease, papain, chymotrypsin, concanavalin A, subtilisin, thermolysin, carboxypeptidase A.

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