PubMed Health⌕ Search

Biomedical subjects

K K Makinen

Publications and source records attributed to K K Makinen.

17 recordsLinked to original sources
PubMed1991

Purification and characterization of a soluble endopeptidase from rat bone.

A soluble endopeptidase was purified from rat bone using ammonium sulphate precipitation followed by Fast Protein Liquid Chromatography on gel, anion exchange, and chromatofocusing columns. The enzyme was silver stain-pure (SDS-PAGE) and its apparent molecular weight was 60,000. In general, the enzyme favored the hydrolysis of the X-Y bond in substrates with the sequence of -Pro-X-Y-Pro-, where either X or Y (or both) were hydrophobic residues. The presence of imino acid residues near the scissile bond favored hydrolysis. The enzyme was strongly inactivated by metal chelating agents and p-hydroxymercuribenzoic acid, indicating that SH-groups may be necessary for full activity of the enzyme and that the enzyme may be a metallopeptidase.

Amino Acid Sequence↗
PubMed1991

Nucleotide sequence of the gelatinase gene (gelE) from Enterococcus faecalis subsp. liquefaciens.

The gene coding for gelatinase (also called metalloendopeptidase II; microbial proteinase, EC 3.4.24.4) of Enterococcus faecalis subsp. liquefaciens strain OG1-10 was cloned in an Escherichia coli-Enterococcus shuttle vector, and its nucleotide sequence was determined. The DNA sequence encodes one large open reading frame (ORF) with 509 amino acid residues. The ORF contains a signal sequence in its N-terminal region, whereas the N-terminal amino acid sequence determined from the purified extracellular proteinase starts at residue 192 deduced from the ORF. This implies that the gelatinase is synthesized as a prepropolypeptide or prezymogen. The mature gelatinase contains 318 amino acid residues (molecular weight, 34,582) and has significant homology with neutral proteinases from Bacillus species and elastase from Pseudomonas aeruginosa.

Amino Acid Sequence↗
PubMed1989

Collagenolytic and phosphatase activity in the rat mandible after functional protrusion.

The effect of chronic mandibular protrusion on the collagenolytic and phosphatase activity of several mandibular bone sites and the condylar cartilage was evaluated. Ninety-three male Sprague-Dawley rats were equally divided into two experimental and one control group. One experimental group wore a protrusive appliance for 2 weeks, the other for 4 weeks. All animals were killed at 59 days of age. Collagenolytic, alkaline and cid phosphatase activities were determined in the condylar cartilage, the subchondral bone and condylar neck, and in the gonial angle and coronoid process. In the cartilage and subchondral bone, the protrusive appliance caused a reduction in collagenolytic and alkaline phosphatase activity. In the condylar neck, it caused a large increase in collagenolytic activity and a decrease in alkaline phosphatase activity in both experimental groups. In the gonial angle and coronoid process, the appliance increased the collagenolytic activity only in the 2-week group. In the 4-week group, the alkaline phosphatase and collagenolytic activities were not different from the activities in those tissues in the control animals. Thus a protrusive appliance induced quantitative changes in enzyme activities in condylar cartilage and mandibular bone. The increase in collagenolytic activity (representing increased bone resorption) occurred typically in areas of muscle attachment and might have been the result of the neuromuscular changes induced by the protrusive appliance. The recovery to normal values of collagenolytic activity in the coronoid process and gonial angle of the 4-week group suggests that at these sites the muscles (and subperiosteal bone) might have adapted to their new biomechanical environment after the longer period of appliance wear.

Acid Phosphatase↗
PubMed1988

Near stoichiometric, irreversible inactivation of bacterial collagenases by o-chloranil (3,4,5,6-tetrachloro-1,2-benzoquinone).

The hydrogen-abstracting quinone derivative 3,4,5,6-tetrachloro-1,2-benzoquinone (o-chloranil) caused a strong, near stoichiometric, irreversible inactivation of the collagenases from Bacillus cereus, Clostridium histolyticum and Achromobacter iophagus. p-Chloranil was a weaker inactivator. o-Chloranil reacted rapidly with a site that affected substrate binding. Amino acid analyses of native and totally inactivated enzymes, and the pH-profile of inactivation suggest that the dissociated form of a tyrosine residue was modified.

Alcaligenes↗
PubMed1988

Xylitol chewing gum in caries prevention: a field study in children.

As the prevalence of dental caries decreases in industrialized nations like the United States, it simultaneously increases in developing nations and Third World countries. The decrease in the West is attributed to increased use of fluorides, but the increase in developing countries has been explained by an increase in the consumption of sugar. As this information continues to propel researchers to find sucrose substitutes, xylitol has been singled out as a proposed sucrose replacement. The question tackled by this study was: Can the daily use of chewing gum containing xylitol increase the efficacy of the existing caries-preventive measures now regularly used for 11- to 15-year-old children in most industrialized western countries?

Adolescent↗
PubMed1988

Relationship between carbohydrate sweeteners and oral diseases.

Dental caries and periodontal disease are wide-spread oral illnesses whose etiology is intimately associated with the consumption of carbohydrate sweeteners. Since dental caries is multifactorial in nature, it is reasonable to assume that there is no single method, usable in the foreseeable future, which would lead to its eradication. Consequently, any new caries preventive measures must function coherently with those currently in use, so that the concerted action of all methods would lead to the best cariostatic effect. Strict restriction of sucrose intake without suggestion of alternatives is not realistic. This fact has given rise to attempts to replace sucrose, especially in products consumed between meals, with sweeteners that are less cariogenic. Human clinical trials and several animal experiments have shown promising clinical results obtained by replacing sucrose with certain sugar alcohols (polyols). Among the sugar alcohols, the best results so far have been obtained with xylitol, which is chemically a pentitol containing five carbon atoms. Chewing gums containing xylitol have been shown to be strong instruments against caries in caries-active age-groups and in high-risk subjects. More research is needed to assess the ability of mixtures of xylitol with sorbitol, palatinit, maltitol, other sugar alcohols, and intense sweeteners to prevent oral plaque diseases. Although thorough clinical trials on the relationship between carbohydrate sweeteners and periodontal diseases have not been performed, the available data indicate that dietary polyols may have a restricted dampening effect on periodontal and gingival inflammations.

Animals↗
PubMed1987

Purification and properties of an extracellular collagenolytic protease produced by the human oral bacterium Bacillus cereus (strain Soc 67).

The major collagenolytic proteinase present in the culture filtrate of Bacillus cereus (strain Soc 67, isolated from the human oral cavity) has been purified to homogeneity by a procedure that comprised concentration of ultrafiltered growth medium on a Millipore PTTK00005 membrane, precipitation with ammonium sulfate, gel permeation chromatography, chromatofocusing, fast protein liquid chromatography on an anion-exchange column, and finally fast protein liquid chromatography on a gel column. The enzyme hydrolyzed, with decreasing rates, phenylazobenzyloxy-carbonyl-L-Pro-L-Leu Gly-L-Pro-D-Arg (PZ-PLGPA), furylacrylolyl-L-Leu-Gly-L-Pro-L-Ala, and furylacryloyl-L-Phe-Gly-Gly, while furylacryloyl-Gly-L-Leu-NH2 was not hydrolyzed. The enzyme degraded soluble and insoluble collagens, Azocoll and gelatin. Bradykinin was hydrolyzed at a high rate at the Phe-Ser bond. The enzyme was sensitive to pyrophosphate, L-cysteine, and L-histidine and could be totally inactivated in the presence of metal chelators. The enzyme contains 1 mol of Zn/mol and the hydrolysis of PZ-PLGPA is slightly increased by Ca2+. The enzyme is readily inhibited by heavy metal cations, but Cu2+ and Ni2+ affected the catalysis in opposite ways: increasing levels of Cu2+ decreased the affinity of the enzyme for PZ-PLGPA, whereas Ni2+ had no effect. The effect of Cu2+ also depended on the pH and type of buffer used. Detailed chemical modification experiments suggested that the active site of the enzyme contains at least 1 tyrosyl and 1 lysyl residue, and 1 carboxyl group. The enzyme was not sensitive to sulfhydryl reagents and thiols did not activate the enzyme. The modification studies were unable to reveal active histidyl residues. The ability of the enzyme to hydrolyze PZ-PLGPA, furylacryloyl-L-Leu-Gly-L-Pro-L-Ala, furylacryloyl-L-Phe-Gly-Gly, and various collagenous materials, its inactivity toward furylacryloyl-Gly-L-Leu-NH2, and the results from the chemical modification studies suggest that the B. cereus (Soc 67) collagenolytic enzyme can be regarded as a true collagenase which resembles the Clostridium histolyticum collagenase(s).

Amino Acid Sequence↗
PubMed1986

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. 50,000 by gel filtration on Sephadex G-100. The pH optimum for the hydrolysis of BAPNA was around 8.5. The enzyme was heat labile and irreversibly inactivated at low pH values. Enzyme activity was enhanced by Ca2+, Mg2+, and Ba2+ but inhibited by Mn2+, Hg2+, Co2+, and Zn2+. Metal chelators and sulfhydryl reagents had no effect on this activity. The enzyme was inhibited by certain protease inhibitors such as diisopropyl fluorophosphate, N-alpha-p-tosyl-L-lysine chloromethyl ketone, phenylmethylsulfonyl fluoride, L-1-tosylamide-2-phenylethylchloromethyl ketone, alpha-1-antitrypsin, and soybean trypsin inhibitor. The Km values for BAPNA and N-alpha-benzoyl-L-arginine ethyl ester were 0.05 and 0.12 mM, respectively, and the Vmax values were higher than those observed with trypsin. Although the purified enzyme hydrolyzed some low-molecular-weight synthetic trypsin substrates, it did not hydrolyze casein, hemoglobin, azocasein, azocoll, bovine serum albumin, or gelatin. Thus, this enzyme is probably not a protease but is capable of hydrolyzing ester, amide, and peptide bonds involving the carboxyl group of arginine and lysine.

Benzoylarginine Nitroanilide↗
PubMed1985

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. Commonly used humectants include sorbitol, a sugar alcohol of the hexitol type, which is used often in sugarless candies. This study showed that when sorbitol in a dentifrice was replaced by xylitol, a sugar alcohol of the pentitol type, the dental plaque of human subjects contained more ammonia and significantly less bacterial polysaccharides. It is accepted generally that ammonia neutralizes plaque acids and that bacterial polysaccharides are involved in promoting caries. Xylitol-containing dentifrice also reduced the saliva levels of S mutans. The results further indicated that if sorbitol and xylitol could be compared in a short-term dentifrice study that relied on subjective and coarse plaque determinations only, no differences between those dentifrices would be found necessarily. To demonstrate the differences between the experimental dentifrices used in this study, it was necessary to analyze specific plaque components and the salivary levels of S mutans.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1977

Xylitol associated changes in amylase and protein content of monkey parotid saliva.

The purpose of this study was to examine amylase activity in the parotid saliva of monkeys fed a high sugar diet supplemented for 3-day periods with either sucrose or xylitol. All monkeys fed xylitol displayed a significant elevation of amylase activity and total protein content in their parotid saliva. The specific activity of amylase (units/mg protein) did not differ between the two diets. The possible importance of this observation to the purported cariostatic action of xylitol is discussed.

Amylases↗
PubMed1977

[Sugar studies at Turku].

This survey concerns the essential findings in two clinical trials. The first study involved almost complete substitution of sucrose (S) by fructose (F) or xylitol (X). After 2 years the mean DMFS-increment was 7.2 in the S-group, 3.8 in the F-group, and 0.0 in the X-group. The second study comprised partial substitution, the effects of a S- or X-containing chewing gum being compared during 1 year. The subjects consumed 4.0 chewing gums per day in the S-group and correspondingly 4.5 in the X-group. In the S-group the caries incidence assessed independently by clinical and radiographical means was significantly higher than in the X-group. It is concluded that the metabolic studies indicate the relative safety of perorally administered xylitol at the present dosage levels. In view on the findings in the chewing gum study it is suggested that the non- and anti-cariogenic properties of xylitol principally depend on its lack of suitability for microbial metabolism and the physico-chemical effects in plaque and saliva brought about through low and repeated dosage.

Calcium↗