Containing No Hexosamine

The polysaccharides of Type VIII pneumococcus, Friedlander s bacillus, Rhizobia and Azoiobader evidently have closely related structures and they contain a high proportion of D-glucose residues. Cross reactions indicated that oxidized cellulose has affinities with this group.  

The mechanism of the conversion of cellulose by the Cytophagae into viscous mucoproteins of high molecular weight forms an unexplored subject of great interest. 

Mucopolyaaccharidea WiOumt Hexoaamine or Uronic Acid Reaidtiea 

In this group we place mainly the neutral bacterial slimes and reserve carbohydrates. They are better defined products than those previously dealt with and as such may of course be regarded as true polysaccharides. Invariably, however, saponification methods are required to rid them of protein residues and to make them water-soluble. The more soluble mold polysaccharides appear to lose their protein constituents by autolytic process during the longer periods required for mold metabolism. Mold slime production can, however, readily be demonstrated on a solid medium. It is proposed here to give briefly some of the types of structure known in the group. 

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Stacey has written an excellent review on the subject of mucopolysaccharides, which he classified on the basis of their containing both hexosamine and hexuronic acid residues, one or the other of these sugar derivatives, or neither. Hyaluronic acid, chondroitinsulfuric acid. Type I pneumococcal polysaccharides, and heparin are members of the first class. Types II, III, and VIII pneumococcal polysaccharides are examples containing hexuronic acid but no hexosamine. Chi tin and Types IV and XIV pneiuno-coccal polysaccharides contain hexosamine but no hexuronic acid and bacterial dextrans, mold polysaccharides, and levans contain neither hexosamine nor hexuronic acid. 

The RBP molecule is a single polypeptide chain of about 180-185 amino acid residues containing three intramolecular disulfide bonds (as cystine residues) (Rask et al., 1981). No fatty acid or fatty acyl chains were detected in purified RBP (Kanai et al., 1968). Analyses for carbohydrate showed that RBP was free of neutral sugar and hexosamine (Peterson, 1971) and had a maximum of 0.9 mol of hexose per mol of protein (Raz et al., 1970). It is likely that RBP contains no bound lipid (other than retinol) and no carbohydrate. 

From Pasteurella tularensis, a polysaccharide was extracted, but no chemical data were given. In another report,the material was thought to contain hexosamine, but qualitative tests for other sugars were negative and the substance gave several lines of precipitation in the antigen-antibody gel-diffusion test. 

In applying the Kuhn methylation to a pentasaccharide isolated from amylopectin a-limit dextrin, the maximum methoxyl content that French, E. E. Smith, and Whelan were able to obtain was 41.8X (theoretical, 49.5%). Quantitative analysis of the hydrolyzate showed that there was no undermethylation, and they concluded that it is essential to wash the product with cyanide after each methylation in order to eliminate chloroform-soluble impurities containing iodine. Kabat and coworkers found that a Kuhn methylation of hexosamines using silver oxide did not give interpretable results, but no problem was experienced when barium oxide was employed. 

Most publications on NVG contain incomplete lipid analyses or none. Craig et al. (1959) examined only some fractions of the liver lipids but not the brain. No chemical analyses were performed in the eight cases of Landing et al. (1964). In the case of Norman et al. (1959) with a cherry-red spot in the macula and hepatomegaly the spleen and liver hexosamine content was increased several-fold, while no neuraminic acid was present. Liver phospholipids but not total lipids were increased. 

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