Serum hexosamine

K35. Kowalewski, K., Serum hexosamine and hydroxyproline in pullets fed atherogenic diet. Arch. Intern. Physiol. Biochim. 70, 631-635 (1962). 

Rimington and Rowlands165 have isolated an extremely active preparation from the serum of pregnant mares. This material was obtained in a high degree of purity and was shown to contain hexose and hexosamine in the molar ratio of 2/1. In the fractionation it appeared that, at first, the hexose content decreases as the potency is raised, but later this trend is reversed. It was shown that hexose content could not be taken as indication of gonadotropic activity. The hexose/hexosamine ratio was 2/1 as in normal serum mucoproteins, so that this gonadotropic hormone may be a modified serum mucoprotein. 

DL-Hexose-hexosamine type serum mucoprotein (protein, mannose, galactose, hexosamine)... 

Glycoproteins of Dihexose-Hexosamine Type These glycoproteins are similar to serum glycoproteins and contain two equivalents of hexoses (maimose and galactose) and one of acetyl-... 

The presence of small amounts of carbohydrates in human serum lipoproteins has been reported by Schultze (1958) and Epstein and Block (1959). Scanu et al. (1958a) found that serum HDL contains 0.5% hexose and 0.35% hexosamine, which remains boimd to the protein after extraction of the lipid moiety by ethanol-diethyl ether. The carbohydrate moiety of serum lipoproteins of d < 1.0 has been reported to... 

Such materials may interfere with the determination of hexosamines (see Chapter VIII). With the colors produced by sialic acid as a reference, Werner and Odin 100) have estimated the amounts of sialic acid in several glycoproteins, including serum glycoprotein and ovomucin. They used Bial s orcinol, the direct Ehrlich reaction, diphenylamine, and tryptophan-perchloric acid. 

These are protein-carbohydrate compounds which contain 10-75% of carbohydrate and over 4% of hexosamines (as distinct from glycoproteins which contain from a trace up to 15% carbohydrate and less than 4% of hexosamines). Oroso-mucoid, haptoglobin and haemopexin are examples of muco-proteins. Increased serum mucoprotein levels are found in many inflammatory conditions such as acute infections and rheumatoid arthritis. Mucoproteins can be estimated by selective precipitation using phosphotungstic acid, followed by determination of the protein or carbohydrate content of the precipitate. 

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