Galactose crystal structure

MHCl, refl. 30 min) gave 2-deoxy-2-fluoro-o-galactose (2DFGal, 86%). The crystal structure of l,3,4,6-tetra-0-acetyl-2-deoxy-2-fluoro-)9-D-galactopyr-anose has been reported. ... 

From the GORGEMA-STD predictions based on the crystal structure, all protons in N-acetyl neuraminic acid and galactose show reasonable STD... 

Figure 16-29 Drawing of the active site of galactose oxidase showing both the Cu(II) atom and the neighboring free radical on tyrosine 272, which has been modified by addition of the thiol of cysteine 228 and oxidation. See Halfen et al.557 Based on a crystal structure of Ito et al.558...

This approach was used to examine the redox chemistry of the Cu site in galactose oxidase (41), which had been proposed to contain an unusual Cu(III) center (52). The lack of a significant Cu K-edge energy shift between the oxidized and reduced forms of the protein demonstrated that the redox chemistry was not metal-centered and implicated another redox active site. The crystal structure of the protein subsequently revealed a novel thioether composed of a cysteine and a tyro-sinate ligand of the Cu site that is likely to be involved in the redox process (53). 

Figure 3. Sketch of the copper coordination in galactose oxidase, as determined by the 1.7 A resolution crystal structure.

Figure 4. Drawing of the stacking interaction between Trp 290 and the thioether bond formed by Cys 228 with Tyr 272 in galactose oxidase as determined from the crystal structure.

For the carbohydrates especially, the amount of available crystal structural data decreases sharply with molecular complexity [479]. With the exception of the cyclodextrins, discussed in Part III, Chapter 18, there are less than 40 crystal structure analyses of oligosaccharides, of which less than 10 are trisaccharides, one is a tetrasaccharide, and one a hexasaccharide (Part III, Chap. 18). The majority of the basic monosaccharides that are the subunits of the polysaccharides that occur naturally have been studied for example, the pyranose forms of /7-arabinose, a-xylose, a- and -glucose, / fructose, a-sorbose, a-mannose, a- and -galactose, a-fucose, a-rhamnose, N-acetyl glucosamine, and mannosamine (Box 13.2). How-... 

Erickson JD, Eiden LE, Hoffman BJ (1992) Expression cloning of a reserpine-sensitive vesicular monoamine transporter. Proc Natl Acad Sci USA 89 10993-10997 Erickson JD, Schafer MK, Bonner TI, Eiden LE, Weihe E (1996) Distinct pharmacological properties and distribution in neurons and endocrine cells of two isoforms of the human vesicular monoamine transporter. Proc Natl Acad Sci USA 93 5166-5171 Faham S, Watanabe A, Besserer GM, Cascio D, Specht A, Hirayama BA, Wright EM, Abramson J (2008) The crystal structure of a sodium galactose transporter reveals mechanistic insights into Na+/sugar symport. Science 321 810-814... 

F re 1. Crystal structure of the active site of galactose oxidase. The substrate... 

Ito N, Phillips SE, Stevens C et al. Novel thioether bond revealed by a 1.7 A crystal structure of galactose oxidase. Nature 1991 350(6313) 87-90. 

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