Glucitol 6-phosphate

There are solitary examples of other alditol phosphates as components of this class of polymers. Arabinitol 1-phosphate is part of the S. pneumoniae type 17F capsular polysaccharide. o-Glucitol 6-phosphate is a component of the group-specific polysaccharide from group B Streptococcus, which has a most unusual, ramified structure. In a polysaccharide from Nocardia... 

Residue D356 is in the same conformation in all other MIPS structures save the 2-deoxy-glucitol-6-phosphate complex structure, a conformation that would occlude the 2-deoxy-glucitol-6-phosphate binding mode seen in this structure. This indicates that this mode of binding is inconsistent with all of these structures. 

The electrostatic potential calculated at neutral pH is positive in the phosphate-binding site defined in the other three structures while it is negative at neutral pH in the phosphate-binding site proposed in the 2-deoxy-glucitol-6-phosphate complex structure. 

The 2-deoxy-glucitol-6-phosphate complex crystals were grown and stabilized at pH 4.5, a pH at which the enzyme is completely inactive. On the other hand, the 2-deoxy-D-glucitol 6-( )-vinyl homophosphonate complex crystals were produced at pH 5.5, where the enzyme retains about half of its activity. 

All of this data lead to the conclusion that 2-deoxy-glucitol-6-phosphate is modeled in a catalytically incompetent conformation, possibly due to the low pH used to produce the crystals. The mechanism based on this structure must then also be disguarded (Jin and Geiger, 2003 Jin et al., 2004 Stein and Geiger, 2002). 

P histidine-containing protein + D-glucitol phosphate S phosphohistidinoprotein -I- D-glucose <1> (<1> enzyme II complex [1])... 

Penicillium ito/icMm/polysaccharides Pseudomonas and Xanthomonas bacteria Streptococci/glucitol phosphate DCl pyrolysis Curie point, 510°C CDS Pyroprobe, 800°C fast ramp FFAP... 

The competitive inhibition of aldolase by a number of structural analogs of D-ftuctose 1,6-diphosphate has been investigated.120 Among these analogs were 1,4-anhydro-DL-ribitol 5-phosphate, 1,4-anhydro-DL-xylitol 5-phosphate, 1,4-anhydro-D-arabinitol 5-phosphate, 2,5-anhydro-D-mannitol 1,6-diphosphate, and 2,5-anhydro-D-glucitol 1,6-diphosphate. Their respective, enzyme-inhibitor,... 

When 15 mM /Va-formyl-/Ve-fructosyl-lysine (fFL) in 0.2 M phosphate buffer, pH 7.4, was incubated in air for 15 d at 37 °C, not only was CML formed, but a substantial amount of lysine was recovered, which N. Ahmed el al.50 and M.U. Ahmed el al.51 interpreted as due to reversal of the Amadori rearrangement. The reduction of the reaction mixture with NaBH4 and subsequent identification of both glucitol and mannitol supports the interpretation. 

Interruption of such a reaction at the intermediate stage should provide more-positive evidence for the mechanism proposed. Treatment of inositol cyclase with charcoal removed the NAD, and, when the enzyme was reconstituted, its properties were found to have been modified. By using this preparation, hydrogen from NADH-t was transferred to C-5 of both xyZo-hexos-5-ulose 6-phosphate (59) and L-sorbose 1-phosphate, giving a mixture of D-glucose-5-f 6-phosphate (58) with lL-mi/o-inositol 1-phosphate (61) or D-glucitol-5-f 6-phosphate, respectively.166 This shows that the enzyme can catalyze the partial reaction corresponding to reduction of the oxidized intermediate proposed. 

Jin, X., Foley, K.M., and Geiger, J.H., 2004, The structure of the lL-myo-inositol-1-phosphate synthase-NAD2+-deoxy-D-glucitol 6-(e)-vinylhomophosphonate complex demands a revision of the enzyme mechanism. J. Biol. Chem. 279 13889-13895. 

D-glucitol.10 The P-0-6-C-6-C-5 torsion angle is —102°. There is an intramolecular hydrogen-bond between O-5-H and one of the phosphate oxygen atoms. The three sodium ions have three different coordinations, namely, distorted tetrahedral, tetragonal pyramidal, and octahedral. 

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