Ref ID : 3844
H.A. Kareem and Anthony T. Soldo; Glycogen in the Marine Protozoon Parauronema acutum. J.Protozool. 25(4):560-562, 1978
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The carbohydrate which accumulates in the cytoplasm of the marine protozoon, Parauronema acutum, during normal growth was isolated, purified and characterized chemically. The highly purified material yielded only glucose residures following hydrolysis in 0.6N HCl for 3 hr at 100 C; measurement of total carbohydrate by the phenol-sulfuric acid method and by treatment with amylo-glucosidase and glucose oxidase gave similar values. Aqueous solutions of the purified material reacted with iodine to form a complex which exhibited an absorption peak at 456 nm with a shift to 484 nm in the presence of 50% saturated (NH4)2SO4. Digestion with alpha-amylase, beta-amylase, and isoamylase yielded 71%, 45% and 8.3% hydrolysis, respectively. Treatment sequentially with both isoamylase and beta-amylase gave complete hydrolysis of the polymer. The average chain length (CL) determined by the isoamylase procedure was 12. These observations are consistent with the view that the carbohydrate isolated from the protozoan is a polymer consisting of alpha-D-glucose residures arranged in chains containing alpha-(1-4) linkages with branch points containing alpha-(1-6) linkages occurring once on the average of ~12 glucose residues and, as such, is indistinguishable from glycogen isolated from mammalian sources.