Purification and characterization of an enzyme produced by Treponema denticola capable of hydrolyzing synthetic trypsin substrates.

An enzyme from Treponema denticola that hydrolyzes a synthetic trypsin substrate, N-alpha-benzoyl-L-arginine-p-nitroanilide (BAPNA), was purified to near homogeneity, as judged by gel electrophoresis. The molecular weight of the enzyme was estimated to be ca. 69,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and ca.

Aggregation of human salivary Ca-proteinates in the presence of simple carbohydrates in vitro.

The effect of 8 polyols and 14 aldoses or ketoses on the spontaneous aggregation of Ca-proteinates was followed spectrophotometrically in supernatants and filtrates of human mixed saliva. Each carbohydrate was added to the saliva samples at 37 degrees C and the precipitated material was analyzed for protein, total carbohydrate and Ca. Based on their effect on aggregation, the carbohydrates could be divided into three groups: 1) those that showed no effect on aggregation: D-xylose, D-ribose and i-erythritol, 2) those that inhibited aggregation strongly: xylitol, D-sorbitol and D-mannitol, and 3) those that inhibited aggregation moderately: glucose, fructose and sucrose.

Alterations in electrolyte and iron metabolism in the rat in relation to peroral administration of galactitol, mannitol and xylitol.

Groups of 12 Long-Evans male rats were exposed to diets containing 20% galactitol (G), mannitol (M) or xylitol (X) for 5 wk. Serum electrolyte concentrations were within normal ranges for rats in all groups compared to control rats. All polyol-fed animals exhibited diuresis and a lower urinary pH (6.

Biochemical, microbiologic, and clinical comparisons between two dentifrices that contain different mixtures of sugar alcohols.

It has been customary to think that in a dentifrice only a few of its ingredients would be active and have clinically significant effects on dental caries, oral hygiene, and the levels of caries-inducive microorganisms or harmful plaque metabolic products. Therefore, most of the emphasis has been placed on the type of fluorine compounds, abrasives, or similar dentifrice ingredients. This study shows that such common dentifrice components as the humectants, which contribute to the texture, rheologic characteristics, and shelf life of the product, also may affect the type of dental plaque grown on the tooth surfaces between toothbrushings or during long-term neglect of toothbrushing or of oral hygiene.

Duodenal xanthine oxidase (EC 1.2.3.2) and ferroxidase activities in the rat in relation to the increased iron absorption caused by peroral xylitol.

The effect of peroral administration of xylitol on the absorption of iron and the activities of xanthine oxidase (EC 1.2.3.

Metabolic effects in rats of high oral doses of galactitol, mannitol and xylitol.

The effect of feeding high amounts of polyols on rat metabolism was studied. Adult male rats were fed the basal diet or the same diet to which had been added either galactitol, mannitol or xylitol for 8 wk (final polyol level 200 g/kg diet). Although all three polyols retarded the growth rate of the animals, the polyols were well tolerated.

Effect of xylitol-, sucrose-, and water-rinses on the composition of human palatine gland secretions.

The chemical composition of stimulated human palatine secretions (HPS) was studied after rinsing with aqueous solutions of sucrose or xylitol, or with water only. Stimulation with water was associated with increased concentration levels of protein. The levels of sialic acids (per mg protein) and the specific arylamidase activities were simultaneously increased, within the physiologic range.

New biochemical aspects of sweeteners.

It has been customary to explain the dentally beneficial effects of xylitol and certain other polyols in terms of microbiological effects only. The almost complete nonfermentability of xylitol in human dental plaque does contribute to the promising clinical findings that have been obtained both in human and animal trials. The nonfermentability or very low fermentability of xylitol by dental plaque leads to a number of consequential phenomena of possible significance in oral biology.

Peroral xylitol increases intestinal calcium absorption in the rat independently of vitamin D action.

The absorption of 45Ca from the diet in the presence of xylitol was investigated with 28 adult male rats. The supplementation of the diet with 10% xylitol for 3 weeks augmented the urinary excretion of 45Ca 2.5-fold p less than 0.

Partial purification and characterization of arylamidases from human palatine secretions.

The secretions (HPS) contained an arylamidase-like enzyme discovered by chromatography on Sephadex G-100 Superfine columns using N-L-alanyl-2-naphthylamine (2NA) as substrate. The enzyme was fractionated in the void volume, suggesting that its molecular weight was 150,000 or higher. It hydrolysed, with decreasing rates, the 2NA of L-alanine, L-leucine, L-methionine and L-phenylalanine, the pH optimum for the best substrate (ala-2NA) being 8.

Antibacterial effect of lactoperoxidase and myeloperoxidase against Bacillus cereus.

An oral periodontopathic bacterium, Bacillus cereus, was inhibited both by lactoperoxidase (LP) and myeloperoxidase (MP) antimicrobial systems. With the LP-SCN--H2O2 system, the growth inhibition was directly proportional to the amount of OSCN- ions present. The OSCN-, which is the principal oxidation product of the LP (or MP)-SCN--H2O2 system at neutral pH, is a normal component of human saliva.

Effect of long-term, peroral administration of sugar alcohols on man.

Certain sugar alcohols (polyols), notably mannitol, sorbitol and xylitol have gained use in food manufacturing for sweetening and technical purposes. These compounds are natural polyols that occur in small amounts in animals and plants. Some sugar alcohols, like xylitol, appear as normal intermediates in the carbohydrate metabolism.

Solubility of calcium salts, enamel, and hydroxyapatite in aqueous solutions of simple carbohydrates.

The solubility of various Ca(II) salts, hydroxyapatite, and powdered human dental enamel in the presence of simple carbohydrates was studied by determining the complex strength between Ca(II) and the carbohydrates. In 1.0 M CaSO4, the following simplified sequence of complex strengths was obtained for the more common carbohydrates: Na-citrate greater than D-sorbitol greater than xylitol greater than D-mannitol greater than D-fructose greater than D-glucose greater than D-xylose.

Peroral xylitol increases the concentration levels of tissue iron in the rat.

The effect of xylitol feeding on the iron content of rat tissues was studied. Adult male rats were fed on the basal diet containing (g/kg) 200 glucose, or 50 or 200 xylitol, or the same diet containing no added carbohydrates for 8 weeks. Each feeding group comprised nine animals.

Modification of the Cl- -activated arginine aminopeptidases from rat liver and human erythrocytes: a comparative study.

The amino acid residues important for the catalytic activity of the Cl- -activated arginine aminopeptidases from human erythrocytes and rat liver were studied using enzyme modification. The general inhibition characteristics were similar with both enzymes. Inactivation with 5,5'-dithiobis-(2-nitrobenzoic acid) revealed one essential SH-group per active enzyme unit in both aminopeptidases.

Composition of human palatine gland secretions and evidence for the presence of specific arylamidases.

After mechanically stimulating the surface of palatine mucosa of adult human subjects, 10-25 microliter of saliva secreted from the openings of the palatine glands were directly collected into graduated glass capillaries. The saliva samples contained large amounts of carbohydrates, sialic acids and hexosamines as a result of the high glycoprotein content of the secretions. The saliva did not show activity from amylase, peroxidase, lysozyme and other typical mixed saliva enzymes, but contained arylamidases at concentrations much higher than mixed saliva from the same subjects.