Sulfate structural studies

Given the efforts in this group and others (Table 1) to form the Cd based II-VI compounds, studies of the formation of Cd atomic layers are of great interest. The most detailed structural studies of Cd UPD have, thus far, been published by Gewirth et al. [270-272]. They have obtained in-situ STM images of uniaxial structures formed during the UPD of Cd on Au(lll), from 0.1 M sulfuric acid solutions. They have also performed extensive chronocoulometric and quartz crystal microbalance (QCM) studies of Cd UPD from sulfate. They have concluded that the structures observed with STM were the result of interactions between deposited Cd and the sulfate electrolyte. However, they do not rule out a contribution from surface reconstructions in accounting for the observed structures. 

Homologous proteins. Homologous proteins usually crystallize under very different conditions. For example, in our laboratory two homologous proteins crystallize in either 10 mM sodium acetate, pH 3.8, 5 mM DTT, and 50% (v/v) MPD (Weichsel et al, 1996), or 100 mM ammonium sulfate, 30% PEG 6000, and 10 mM DTT (Filson et al, 2003). This technique was first used by Kendrew for solving the structure of sperm whale myoglobin (Kendrew et al., 1954) and has been used in many other structural studies. Currently, this technique is heavily exploited in membrane protein crystallography (Wiener,... 

Yun, S-S., Scott, A. P., and Li, W. (2003). Pheromones of the male sea lamprey, Petromyzon marinusL. structural studies on a new compound, 3-keto allocholic acid, and 3-keto petromyzonol sulfate. Steroids 68,297-304. 

It had been realized from the beginning that the final goal was the application of the new methods to structural studies in the wider fields of oligosaccharides and polysaccharides. The important reference substance, 2,3,6-trimethyl-D-glucose was isolated by Denham in the course of work at St. Andrews on the methylation of cellulose in which he made use of dimethyl sulfate as the methylating agent. 

N. K. Kochetkov, G. P. Smirnova, and N. V. Chekareva, Isolation and structural studies of a sulfated sialosphingolipid from the sea urchin Echinocardium cordatum, Biochim. Biophys. Acta, 424 (1976) 274-283. 

Sugahara K, Yamashina 1, Dewaard P, Vanhalbeek H, Vhegen-thart JFG. Structural studies on sulfated glycopeptides from the carbohydrate-protein linkage region of chondroitin 4-sulfate proteoglycans of swarm rat chondrosarcoma - demonstration of 86. the structure Gal(4-0-Sulfate)-P-l-3-Gal-P-l-4Xyl-P-l-0-Ser. J. 

C6. Cifonelli, J. A., and Dorfman, A., Structural studies on herapin and heparitin sulfate. Biochem. Biophys. Res. Commun. 4, 328-331 (1961). 

FIGURE 8.11 Hydrated copper(ll) sulfate, CuS04 5H20, is blue (left), but the anhydrous compound, CUSO4, is greenish white (right). A structural study of the solid compound demonstrates that four of the water molecules are closely associated with the copper and the fifth is not. Thus, a better representation of the hydrated compound is [Cu(H20)4]S04-H20. 

Stromberg, K., Hurley, N. E., Davis, N. L., Rueckert, R. R and Fleissner, E. (1974) Structural studies of avian myeloblastosis virus comparison of polypeptides in virion and core component by dodecyl sulfate-polyacrylamide gel electrophoresis.. /. Virol. 13, 513-528. 

A structural study of receptors 51, 52, and 49, showed three different modes of azide complexation to the binuclear copper(II) host (123) 1,1 cascaded, 1,3 cascaded, and noncascaded, respectively. These structures indicate that the nature of the macrocyclic framework of the receptor is important in determining the mode of anion coordination. Figure 5(a and b) shows the crystal structures of 52, 2 Cu(II)-azide, and 52, 2Cu(II)-chloride, respectively, for comparison (129). As can be seen, it is the length of the azide bridge that makes cascade complexation possible, whereas for the smaller mononuclear chloride anion this obviously cannot occur. Receptor 49 has also been shown to cascade bind pyrophosphate [as its bis-copper(II) complex] (130) and sulfate [as its bis-iron(II) complex](131). At about the same time, Nelson and co-workers (132) published a similar bis-copper(II) complex structure that cascaded an azide anion. 

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