Effect of maturity and curing on peanut proteins. Changes in protein surface hydrophobicity.

A hydrophobic fluorescence probe, 1,8-anilinonaphthalene sulfonate (ANS), was used to study the changes in protein surface hydrophobicity (PSH) occurring during peanut maturation and curing. PSH increased with the degree of maturity and during curing (windrow drying). The increase of PSH during curing or heating was more pronounced in immature peanuts than their mature counterparts, suggesting that more hydrophobic sites are hidden in the former proteins. PSH decreased when proteins were chemically modified with phenylglyoxal (an arginine-modifying agent), suggesting that arginine might play a role in hydrophobicity. The findings indicate that maturation and curing affect PSH, and that there is a relationship between PSH and peanut maturity. Possible factors contributing to the increase of PSH are discussed.

Pharmacokinetics of catalytically tritiated glycosaminoglycans in the rat.

Glycosaminoglycan mixture catalytically labelled with tritium gas (3H-GAG) was shown to have chemical characteristics and antithrombin-heparin cofactor activity in vitro similar to those of the native mixture of glycosaminoglycans (GAG). Rats were orally dosed with 3H-GAG in either aqueous solution or vegetable oil emulsion and the quantity of radioisotope absorbed assessed at various intervals. The quantity of 3H in plasma plateaued 8 h after dosing and remained near peak levels at least 16 h. Time dependent accumulation of the radioisotope within liver, spleen and testes was also observed.

Glycosaminoglycans from pig duodenum.

A polysaccharide extract from pig duodenum, used in therapy as antilipemic, was shown by chromatographic and electrophoretic methods to be a mixture of the glycosaminoglycans (GAG) heparin (HEP), heparan sulfate (HS), dermatan sulfate (DeS), chondroitin sulfates (ChS) and hyaluronic acid (HA), in the ratio 24:31:23:9:13. The GAG mixture was fractionated with alkyl-ammonium salts, and, for DeS, with copper salts. Further purification of the fractions either by repeated complexation or by removal of residual impurities using specific enzymes or chemical reactions, permitted obtaining individual GAG more than 97% pure by electrophoretic and 1H-NMR analysis. These preparations will be used to assess the contribution of individual GAG to the biological activity of duodenal GAG extracts.

Complex carbohydrate breakdown in the human colon.

Concentrations of water-soluble high- and low-molecular-weight carbohydrates were determined in the intestinal contents of four human subjects who had died accidentally. In all four subjects, concentrations of high-molecular-weight carbohydrate were lower throughout the colon than in the ileum. In some subjects, similar but less dramatic differences were also found with low-molecular-weight carbohydrate. Components of both high- and low-molecular-weight peaks included neutral sugars such as rhamnose, galactose, mannose, xylose, and arabinose, which are found in many plant polysaccharides. Components characteristic of mucins (fucose, hexosamines, and sialic acids) were also detected. These results indicate that dietary fiber and mucin are degraded in the human colon.

Fermentation of mucins and plant polysaccharides by anaerobic bacteria from the human colon.

A total of 154 strains from 22 species of Bifidobacterium, Peptostreptococcus, Lactobacillus, Ruminococcus, Coprococcus, Eubacterium, and Fusobacterium, which are present in high concentrations in the human colon, were surveyed for their ability to ferment 21 different complex carbohydrates. Plant polysaccharides, including amylose, amylopectin, pectin, polygalacturonate, xylan, laminarin, guar gum, locust bean gum, gum ghatti, gum arabic, and gum tragacanth, were fermented by some strains from Bifidobacterium, Peptostreptococcus, Ruminococcus, and Eubacterium species. Porcine gastric mucin, which was fermented by some strains of Ruminococcus torques and Bifidobacterium bifidum, was the only mucin utilized by any of the strains tested.

Breakdown of mucin and plant polysaccharides in the human colon.

To obtain an estimate of the extent to which complex carbohydrates are degraded by bacteria in the human colon, aqueous extracts of colon contents from four human subjects were separated into high and low molecular weight fractions by chromatography on a Sephadex G-100 column. The composition of these fractions was compared with the composition of similar fractions from ileal contents, i.e., from material entering the colon. In all four subjects, high molecular weight carbohydrate concentrations were lower in the colon than in the ileum, indicating that breakdown of complex carbohydrate occurs in the colon. The high molecular weight carbohydrate fraction contained sugars characteristic of plant polysaccharides (arabinose, xylose, mannose, rhamnose) as well as sugars characteristic of mucin (fucose, hexosamines, sialic acids). Concentrations of most of these sugars were uniformly lower in the colon than in the ileum. Since high molecular weight protein concentrations were lower in the colon than in the ileum of two of the four subjects tested, some degradation of protein may also occur in the colon.

High-pressure liquid-chromatographic assay of nucleotide-pool concentrations during polysaccharide biosynthesis in four ascomycetes.

High-resolution liquid-chromatographic methods developed for analyzing nucleotide pools at the nanogram level in four representative species of ascomycetes (Penicillium citrinum, Aspergillus niger, Fusarium moniliforme, and Cladosporium herbarum) were used to study polysaccharide biosynthesis. Nucleotides extracted from the mycelial mat were preseparated from interfering polysaccharides, glycoproteins, and nucleic acids on a column of Biogel P-2. Resolution of 18 nucleotides from each fungal species was accomplished on AS-Pellionex-SAX, pellicular anion-exchanger by using a high-pressure liquid chromatograph. Nucleotides were identified by comparing peak retention-times, by differential u.v. absorption with two detectors in series at selected wavelengths, and by acid or enzymic hydrolysis with product identification by liquid chromatography. Pyrimidine bases exceeded purines by at least three fold, and uridine nucleotides often constituted 60-80 mole percent of the total nucleotides; extractable cytidine nucleotides were negligible. Uridine 5'-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl disphosphate) is the preponderant nucleotide throughout the growth cycles of all four species, amounting to 30-60% of all nucleotides present. For all four fungal species, a burst of nucleotide formation was observed after the first 48h (15-30 mumol/g tissue), with fluctuations that eventually fell to 0.1 mumol/g on the tenth day.

On arabinose as a component of brain hyaluronate. Confirmation by chromatographic, enzymatic and chemical ionization-mass spectrometric analyses.

The controversy about the presence of the pentose arabinose in brain hyaluronate was reinvestigated using modern analytical tehcnics. The purified bovine brain hyaluronate contained the neutral sugars: arabinose, 0.18%; glucose, 0.05%; and fucose, 0.22%. The confirmation of the presence of arabinose was obtained by paper and thin layer chromatography of the neutral sugars in deionized hyaluronate hydrolysate. Gas-liquid chromatography of the aldononitrile peracetate of the pentose isolated by preparative paper chromatography gave a single distinct peak, corresponding to standard arabinose on three columns packed with three different phases. Chemical ionization data and mass spectrum of the aldononitrile peracetate derivative agreed with those of the authentic arabinonitrile tetracetate. Analysis of the isolated pentose with the help of the enzymes L-arabinose isomerase and L-ribulose kinase, which are specific for their substrates, further established its identity as L-arabinose.

Fermentation of mucin and plant polysaccharides by strains of Bacteroides from the human colon.

Ten Bacteroides species found in the human colon were surveyed for their ability to ferment mucins and plant polysaccharides ("dietary fiber"). A number of strains fermented mucopolysaccharides (heparin, hyaluronate, and chondroitin sulfate) and ovomucoid. Only 3 of the 188 strains tested fermented beef submaxillary mucin, and none fermented porcine gastric mucin. Many of the Bacteroides strains tested were also able to ferment a variety of plant polysaccharides, including amylose, dextran, pectin, gum tragacanth, gum guar, larch arabinogalactan, alginate, and laminarin. Some plant polysaccharides such as gum arabic, gum karaya, gum ghatti and fucoidan, were not utilized by any of the strains tested. The ability to utilize mucins and plant polysaccharides varied considerably among the Bacteroides species tested.