Carbohydrates Composition

Glycophorin A appears to serve a variety of functions on the red-cell membrane, and has been implicated in several red-cell disorders. Because it extends from the external environment of the cell into the cell cytoplasm, it is considered to constitute a receptor for malarial parasites,"" influenza viruses, lectins, and Portuguese man-of-war toxin. Many of these receptor functions are attributable to the carbohydrate composition of these... 

Table II. Carbohydrate compositions (weight percentage) of individual oligomer peaks purified (QAE-Sephadex or HPLC ion-exchange separation, respectively) from mixtures of citrus pectin oligomers or B fruit extracts Compositions shown are for peaks whose biological activity is described in Figure 4. Uronic acid values are based on colorimetric assay. Proportions of neutral sugars were determined by GC and adjusted so that totals equal 100%. In fact, some oligomers (G7 peaks 8, 9 and 10. B extract peak 10) produced small (less than 1 % of the total integrated area), unknown peaks in the GC chromatograms.

Changes in molecular weight and carbohydrate composition of cell wall polyuronide and hemicellulose during ripening in strawberry fruit... 

The cambium was isolated firom spruce (Picea abies) logs felled in October-November. The bark was stripped off, and the cambium was removed by gentle scraping. The isolated cambium was immediately fiozen in liquid nitrogen and fi-eeze-dried. The carbohydrate composition of the isolated cambium was analysed by HPLC after enzymatic hydrolysis using Pectinex Ultra and a mixture of cellulases and hemicellulases (Buchert et al 1993). 

Honey has been produced in Lithuania since the ancient times. Baltrusaityte et ah (2007a,b) recently reported antimicrobial and antioxidant properties of Lithuanian honeys. Kaskoniene et ah (2010) characterized the carbohydrate composition of Lithuanian honeys obtained from various sources and determined if there was any relationship between pollen content and the content of the carbohydrate in the honey. 

Kaskoniene, V., Venskutonis, P. R., and Ceksteryte, V. (2010). Carbohydrate composition and electrical conductivity of different origin honeys from Lithuania. LWT Food Sci. Technol. 43, 801-807. 

Recent applications of HPAEC-PAD are many and varied. A representative list includes quantitation of polyglucose metabolites in plasma of dialysis patients,148 analysis of heat-treated milk,149 carbohydrate content in lipopolysaccharides,150 phosphorylated sugars in tissue samples,151 composition of soybean meal,152 carbohydrate composition of recombinant modified tissue plasminogen activator,153 analysis of cyclization products from an enzyme reaction,154 carbohydrate content of glycoconjugate vaccines,155 and monitoring of patients with rheumatoid arthritis.156... 

Rouiller DG, Sharon N, McElduff A, Podskalny JM, Gorden P 1986 Lectins as probes of insulin receptor carbohydrate composition studies in glycosylation mutants of Chinese hamster ovarian cells with altered insulin binding. Endocrinology 118 1159-1165... 

Characterization of the exact nature of the post-translational modifications the mammary system is capable of undertaking. For example, the carbohydrate composition of tPA produced in this system differs from the recombinant enzyme produced in murine cell culture systems. 

Carbohydrate composition, determined by HPLC, are expressed as % by weight. All values are averages of two separate determinations. 

The two preparations from A. oryzae reportedly differ in amino acid and carbohydrate composition. The enzyme prepared by Minato contained 25% carbohydrate no cysteine was detected either by titration with p-mercuribenzoate in 6M urea or by cysteic acid analysis after performic acid oxidation (179). In contrast, Wolfenden et al. (92) reported 14 cysteine residues per mole of enzyme which reacted instantaneously with p-mercuribenzoate in the absence of urea. No explanation is available for this apparent discrepancy. 

Finally, this section would remain incomplete without a few comments on the applications of HPLC to a particular group of carbohydrates—polysaccharides—whose determination, both qualitatively and quantitatively, has received much less attention than the rest (56). This may be surprising when the importance of these compounds, in terms of both functional properties and nutrition, is considered, but it is not so surprising when the difficulty of the analyses required is studied. High-performance LC can be used in this field, either to characterize the polysaccharides per se or to study their carbohydrate composition and the nature of bonding after acid or enzymic hydrolysis. 

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