D-glucuronic acid residues

In the cell-wall antigen from Staphylococcus aureus M, taurine is linked as an amide (51) to a 2-acetamido-2-deoxy-D-galactosyluronic residue. l-Threonine and L-glutamic acid are linked as amides to D-glucuronic acid residues in the LPS from Rhodopseudomonas sphaeroides ATCC 17023 and in the capsular polysaccharide from Klebsiella K82, respectively. In the capsular polysaccharide from E. coli K54, L-serine and L-threonine, in the ratio 1 9, are linked to the carboxyl group of a D-glucuronic acid residue. In the capsular polysaccharide from Haemophilus influenzae type d,... 

In contrast to L-iduronic acid residues, most of which are sulfated at C-2, D-glucuronic acid residues in heparin and heparan sulfate are largely or exclusively nonsulfated. This was especially proved by their susceptibility to periodate oxidation,123 and through characterization of D-glucuronic acid-containing di- and tetra-saccharides from deamina-tive104 109 110 138 or heparinase - heparanase cleavage137,145 of heparin. 

From pig mucosa. Notations as for Scheme 1. Major products (yield 40-80% of original heparin). Major disaccharide fraction (50-80%). From heparin chains terminating with a D-glucuronic acid residue at the reducing end. Minor products (yield <3% of original heparin). From the active site for antithrombin (asterisk denotes 3-C-sulfation of the amino sugar or anhydro-D-mannose). 

Scheme 4. —Smith Degradation of Heparin (Arbitrary Sequence). (R = remnant from a D-glucuronic acid residue.)...

Reeves and Goebel72 have shown that hydrolysis of the reduced methylated capsular polysaccharide of Type III pneumococcus yields 2,3,6-trimethyl-D-glucose and the anomeric forms of methyl 2,4-dimethyl-D-glucoside. The cellobiuronic acid units in the polysaccharide are thus linked through position 3 of the D-glucuronic acid residue, probably by /3-D-linkages. That is, the polysaccharide contains alternate 1,3-and l,4-/3-D-linkages. 

The repeat distance is 18.6 A (1.86 nm), with a meridional reflection on the first layer-line. A tetrasaccharide repeating-unit was favored. It was suggested that the linkage between the 2-acetamido-2-deoxy-D-glucose and D-glucuronic acid residues is alternately a-D-(l — 4) and /3-d-(1 — 4). 

Figure 3.8(a) Possible ester linkage between an a-OH of lignin and a carboxyl group of a 4-0-methyl-/3-d-glucuronic acid residue on the xylan backbone. 

In the sequence analysis of the Klebsiella type 59 capsular polysaccharide, the terminal D-glucuronic acid residue was eliminated... 

As previously mentioned, Kauss (40) has shown that the methyl donor for the formation of 4-methyl-D-glucuronic acid of hemicellulose B proved to be S-adenosyl-L-methionine, the same as in pectin. A particulate preparation from immature com cobs containing hemicellulose B was found capable of transferring the 14C-labeled methyl group from S-adeno-syl-L-methionine to a macromolecular acceptor present in the particles. The radioactive product was shown to be hemicellulose B labeled in the 4-methyl-D-glucuronic acid residues. It was isolated chiefly as 4-methyl-glucuronosyl-( 1 - 2)-D-xylose. 

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