Measurements of alkaline phosphatase activity in fetal bovine enamel.
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Biomedical subjects
Publications and source records attributed to D Moe.
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The localization of reaction product for non-specific esterase from fresh and aldehyde treated glandular tissue was examined. The electrophoretical studies showed a selective inhibition of certain isoenzymes and a change in mobility of some bands caused by aldehyde fixation. In sections a granular reaction could be identified after 5 min fixation with 1% formaldehyde while no such staining was visible in fresh tissue.
20 reference strains and 72 isolated strains from dental plaque of streptococci, actinomyces, and lactobacilli species were examined for sucrase and maltase activities. The type of sucrase in the different strains was determined by use of the alpha-glucosidase inhibitor, acarbose. The enzyme activities were determined as formation of monosaccharide, and quantitated spectrophotometrically. Although variations occurred in enzyme activities between reference and isolated strains, the same general pattern was noticed. Strains of Streptococcus mutans and S. salivarius showed regularly the highest sucrase activities, followed by strains of Actinomyces viscosus and A. naeslundii. Most lactobacilli belonged to the bacteria with low sucrase activity like S. sanguis and S. mitior. In some lactobacilli strains, however, a high sucrase activity was observed. The level of sucrase activity in S. mutans strains was dependent on biotype/serotype, as strains of biotype V/serotype e showed high activities, biotypes I and IV corresponding to serotypes c, f, and d showed intermediate activity, and biotype III/serotype a always showed low activity. In most of the strains the sucrases were composed of enzymes with specificity against both alpha-glucosidic linkage and beta-fructosidic linkage of the sucrose molecule, but in varying ratios. In all species, exept S. sanguis and S. mitior, lower maltase than sucrase activity was observed, but even in the two species mentioned the maltase activities were relatively low. On the basis of observations of selected reference strains in every species examined both sucrases and maltases are to some extent inducible.
Two multi-step extraction procedures were used to isolate matrix proteins from fetal bovine enamel. Using SDS-PAGE and gel isoelectric focusing it was concluded that extraction procedures influence the number of protein bands in the gel, their pI, apparent molecular weight and staining intensity.
Using simultaneous coupling azo dye techniques kidney enzymes active against alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester are characterized. The enzymes show identical distribution in the section. The banding patterns in zymograms are the same after incubation with the different substrates. The enzymes might, however, be separated by difference in pH optimum, initial velocity and sensitivity to inhibitors and activators.
Seven known alpha-glucosidase/beta-fructosidase inhibitors were examined for inhibitory effect against invertases in pooled human dental plaque. The inhibitors used were acarbose, Trestatin, nojirimycin, 1-deoxynojirimycin, glucono-delta-lactam, conduritol-B-epoxide, and Hoe 467A. Plaque homogenates were incubated with 14C-labelled sucrose and invertase activity was assayed by determination of radio-labelled monosaccharide after paper chromatography. Conduritol-B-epoxide, acarbose, and Trestatin reduced the invertase activity an average of 62%, 51%, and 35% respectively. The other inhibitors affected the enzyme activity negligibly. By combining conduritol-B-epoxide with acarbose or Trestatin in other plaque homogenates the inhibition of invertases increased from 35% to 61%. This observation supported the concept that the invertases in dental plaque consist of both alpha-glucosidases and beta-fructosidases.
The dissolution of two analytical calcium fluoride preparations was studied in aqueous solution. Dissolved calcium fluoride was determined from analysis of Ca and F in solution. Original samples of the two preparations and the residue after partial dissolution were studied by X-ray diffractometry in comparison with natural fluorite. The dissolution of calcium fluoride was found to be extremely slow. After a period of 1-15 weeks, depending on the experimental conditions, a state was reached where apparently no further dissolution occurred, although the solution was far from saturation. The dissolution rate was obviously closely related to the crystal size. On partial dissolution the mean crystal size increased, probably due to the disappearance of the finest fractions. Placing the salt in a dialysis bag before immersion in the water lowered the dissolution rate and increased the undissolved fraction considerably. The results seem to support the assertion that calcium fluoride accumulated in early carious lesions after topical applications of fluoride may persist for considerable periods of time.
Activity of acid phosphatase and beta-glucuronidase was shown in bovine preodontoblasts and preameloblasts prior to the onset of secretion. In the preameloblasts the rather weak reaction consisted of small discrete granules dispersed in the cytoplasm apical, lateral, and proximal to the nucleus. After initiation of enamel formation, a change in localization and intensity of the colored reaction product was observed in the ameloblasts. The activity appeared stronger and was restricted to a narrow zone just apical to the nucleus. It is proposed that the acid hydrolases in the tooth forming cells are located to the Golgi complex. The differences in activity of acid hydrolases between bone and tooth forming cells are expounded.
Supragingival plaque samples were examined for alpha-amylase activity before and after cultivation. Amylase activity was determined by disappearance of 14C-labeled starch in a phosphate buffer, pH 6.9. In all plaque samples alpha-amylase activity was observed. On an average 75% of this activity was soluble, while the rest was bound to various plaque components. Known inhibitors of human alpha-amylase inhibited the enzyme activity in the plaque samples almost totally. The electrophoretic patterns of alpha-amylases in the plaque and human saliva samples were identical. Bacteria cultivated from the plaque samples showed no or low alpha-amylase activity. The results indicated that most of alpha-amylase activity in supragingival plaque samples are of salivary origin. The greater part of the enzyme activity is extracellular in the plaque, may be located at the plaque surface, and only a minor part is bound to the cells or to the insoluble components in the plaque.
As a preliminary study the keratin proteins of human oral stratified epithelia from buccal mucosa and hard palate were investigated using SDS-PAGE technique. The keratinized hard palate consistently showed six polypeptides varying in molecular weight from 47 to 67 k daltons, whereas the nonkeratinized buccal epithelium lacked the larger polypeptides and showed three polypeptides with molecular weight from 50 to 56 k daltons. The individual variations in the SDS-gel pattern from eight clinically normal individuals were restricted to minor quantitative differences.
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Inhibition of microbial enzymes in human dental plaque catalyzing the cleavage of the disaccharides maltose, sucrose and lactose was carried out with the alpha-glucosidase inhibitor, acarbose. The maltases from plaque homogenates were totally inhibited, whereas the inhibition of the invertases varied considerably. With increasing inhibitor concentrations, from 1 mM to 50 mM, the inhibition of the invertases increased. Preincubation for 30 min of the plaque homogenate with inhibitor resulted in a 20% increase of the inhibition of invertase activity. The inhibitor showed non-competitive inhibition of the invertases in the homogenates, whereas the maltases were competitively inhibited. The lactases were not inhibited at all. The invertases from human dental plaque may be alpha-glucosidases and/or beta-fructosidases.
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In this paper a localized strong reaction for non-specific esterase forming cylindric structures is described within skeletal muscle fibres from the beige mouse. It seems from zymograms and protein electrophoresis that this esterase is membrane bound, highly reactive and present in rather small amounts within the muscle fibres.
Supragingival human dental plaque was collected from patients with evidence of caries. The plaque was frozen and stored at -20 degrees C. Pooled plaque was homogenized in acetate buffer pH 5.0 in an ice-water bath. By incubating the homogenate at pH 5.0 with [U-14C]-sucrose the formation of glucose and fructose was followed. Incubation in acetate buffer at pH 5.0 eliminated the glycosyltransferase activities and the glycolytic pathway. Normal Michaelis-Menten kinetics were observed until about 40 mM sucrose. At higher concentration of sucrose, excess substrate inhibition occurred. Storage of the homogenate at -20 degrees C resulted in decrease of the invertase activity with time.
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