B-Glyceraldehyde

FIGURE 6.34 Sheet structures formed from andparallel arrangements of /3-strands, (a) Streptomyces suh i x Xu inhibitor, (b) glutathione reductase domain 3, and (c) the second domain of glyceraldehyde-3-phosphate dehydrogenase represent minimal andparallel /S-sheet domain structures. In each of these cases, an andparallel /S-sheet is largely exposed to solvent on one face and covered by helices and random coils on the other face. (Jane Richardson)... 

FIGURE 19.30 (a) Pyruvate reduction to ethanol in yeast provides a means for regenerating NAD consumed in the glyceraldehyde-3-P dehydrogenase reaction, (b) In oxygen-depleted muscle, NAD is regenerated in the lactate dehydrogenase reaction. 

Figure 9.9 Assigning configuration to (a) (-)-glyceraldehyde and (b) ( r)-alanine. Both happen to have the Sconfiguration, although one is levorotatory and the other is dextrorotatory.

Since the equilibrium reaction mixture contains at least four products, workup can be difficult and therefore, it may be helpful to bring the reaction to completion. For example, in the transketolase-catalyzed reaction of [l-13C]D-ribosc 5-phosphate and [l-l3C]D-i/ /w-2-pen-tulose 5-phosphatc to [l,3-13C]n-a/b,o-2-heptulose 7-phosphate and D-glyceraldehyde 3-phos-... 

Figure 10.46 Application of ThrA catalysis for the stereoselective synthesis of dihydroxyprolines from glyceraldehyde, and an adenylamino acid for RNA mimics (a). ThrA based preparation of precursors to the immunosuppressive lipid mycestericin and the antibiotic thiamphenicol (b).

We ran a second set of experiments to examine the reactivity of glyceraldehyde withont interference from glucose. This set of studies is referred to as Experiment B. The resnlts of the experiment are shown in Table 46.3 and Figure 46.5. The results match what was observed in Experiment A. The molar balance of aronnd 80% indicates abont 20% formation of condensation heavies not observed by HPLC. 

The hexose phosphate, fructose-1,6-diphosphate, is split by aldolase into two triose phosphates glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Aldolase consists of four 40-kDa subunits. Three tissue-specific forms exist in human tissues aldolase A (ubiquitous and very active in the muscle), aldolase B (liver, kidney, and small intestine), and aldolase C (specific to the brain). These three isozymes have nearly the same molecular size but differ in substrate specificity,... 

Maier, W., B. Schneider et al. (1998). Biosynthesis of sesquiterpenoid cyclohexenone derivatives in mycorrhizal barley roots proceeds via the glyceraldehyde 3-phosphate/pyruvate pathway. Tetrahedron Lett. 39(7) 521-524. 

Modun, B. and Williams, P. (1999). The staphylococcal transferrin-binding protein is a cell wall glyceraldehyde-3-phosphate dehydrogenase, Infect. Immun., 67, 1086-1092. 

These results may be explained on the basis that xylan possesses a linear chain of 1,4-linked anhydroxylose units. However, it should be pointed out that on hydrolysis of the oxidized xylan, some D-xylose is found in addition to the expected glyceraldehyde and glyoxal.I04(b) While it is possible that the oxidation reaction is not complete, another explanation is that a branched xylan chain may be present. If branching occurs on a pentose chain unit, only one free hydroxyl would remain on the unit hence, it would not be oxidized or degraded during the course of the periodate reaction. 

Velick, S.F. (1954). The alcohol and glyceraldehyde-3-phosphate dehydrogenases of yeast and mammals. In The Mechanism of Enzyme Action. (McElroy, W.D. Glass, B., Eds.), pp. 491-519. The Johns Hopkins Press, Baltimore. 

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