Glucosamine, component

One of the most characteristic differences between papain and the other sulfhydryl proteases, ficin and bromelain, is the absence of carbohydrate in papain. Glycopeptides have been isolated from ficin (48) and bromelain (49, 50, 51, 52). In the case of bromelain the carbohydrate moiety composed of mannose, xylose, fucose, and N-acetylglucosamine is covalently linked to an asparagine residue of the peptide chain through a glucosamine component of the sugar moiety (51,52). 

Streptozotocin is unique both in origin and pharmacology. It is an antibiotic obtained from Streptomyces achromogenes and contains a glucosamine component in its structure, which may contribute to its tendency to be taken up into the P-cells of the islets of Langerhans of the pancreas. Where it was initially used to induce diabetes in experimental animals, it is now used to treat pancreatic islet cell carcinoma, resulting in about a 50% response rate, but few survivors past 1 year. 

Most of the LPS biological activity (pyrogenicity) is associated with its lipid A moiety. This usually consists of six or more fatty acids attached directly to sugars such as glucosamine. Again, as is the case in relation to the carbohydrate component, lipid A moieties of LPS isolated from different bacteria can vary somewhat. The structure of E coli s lipid A has been studied in the greatest detail its exact structure has been elucidated and it can be chemically synthesized. 

The other component parts of streptomycin, namely L-streptose and the aminosugar 2-deoxy-2-methylamino-L-glucose (A -methyl-L-glucosamine), are also ultimately derived from o-glucose. Gentamicin Ci contains two aminosugars, L-garosamine and D-purpurosamine. 

The acetylated amino sugars N-acetyl-D-glucosamine and N-acetyl-D-Galactosamine (4) are often encountered as components of glycoproteins. 

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