Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spectral changes of hemoproteins in the near ultraviolet region on binding to a ligand and on oxidation-reduction of the heme-iron were studied by computer-controlled spectrophotometry. Near ultraviolet difference spectra between the low spin and high spin forms of ferric hemoproteins were classified into three groups: Those showing two absorption peaks having maxima at around 285 and 295 nm, those showing a peak at around 275 nm, and those showing a peak at around 300 nm. No corresponding absorption peak was observed with model heme complexes of low molecular weight. The intensity of the peak in cyanide difference spectra of catalase and horseradish peroxidase in the near ultraviolet region was dependent on the concentration of added cyanide and paralleled the intensity of the spectral changes in the Soret region. The spectral changes in both the near ultraviolet and Soret regions developed within 6 ms after the addition of cyanide. Difference spectra between the reduced and oxidized forms of cytochrome c, cytochrome oxidase-cyanide complex, hemoglobin, and lactoperoxidase-cyanide complex showed a characteristic peak at around 285-290 nm. Various difference spectra of hemoglobin in the near ultraviolet region were also measured. The observed positions, shapes, combinations, and relative intensities of the peaks were compared with those of solvent perturbation difference spectra and pH difference spectra of proteins and aromatic amino acids and also with the diacetylchitobiose-induced difference spectrum of lysozyme. The kinds of aromatic amino acid residues possibly responsible for the observed difference peaks were discussed on the basis of the results of the comparison. Based on the results obtained, the common occurrence of a heme-linked functional response of the hemoprotein conformation was suggested.
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PMID:Heme-linked spectral changes of the protein moiety of hemoproteins in the near ultraviolet region. 298 98

High-molecular-weight polymers of alpha-1,6-linked D-glucans are insoluble in alcohol solutions. Whole, but not parotid, saliva prevented the precipitation of D-glucans by 80% (vol/vol) ethanol, showing that the whole saliva contained a factor which complexed with the glucan to render it alcohol soluble. The glucan-binding factor was retained on a column of Sephacryl S-200 which had been preequilibrated with 80% ethanol. The factor was then eluted with water. Passive hemagglutination assays revealed that the glucan-binding factor could sensitize erythrocytes to agglutination with anti-poly(glycerolphosphate), suggesting that the active glucan-binding component with lipoteichoic acid. The glucan-solubilizing factor was resistant to heat (100 degrees C), proteases, sialidase, lysozyme, lactoperoxidase, trichloroacetic acid, and Triton X-100. When sucrose was added to saliva, a suspension of Streptococcus cricetus AHT, or a suspension of Streptococcus sanguis 10556, relatively large amounts of glucan-binding factor were released in a soluble form. In addition, penicillin G caused the release of the glucan-solubilizing component from a suspension of S. cricetus AHT. It is suggested that whole saliva contains a component, tentatively identified as lipoteichoic acid, which can complex with glucans in a relatively hydrophobic solvent. This type of complex formation may be important in the adhesion of oral streptococci to saliva-coated surfaces.
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PMID:Glucan-binding factor in saliva. 316 92

The purpose of the present study was to give a clinical and biochemical characterization of two groups of individuals with different rates of plaque formation. From 133 individuals, 9 "heavy" and 10 "light" plaque formers were selected. The mean plaque index after 3 days of plaque accumulation, on buccal surfaces of premolars and first molars, was 2.6 for the "heavy" and 0.6 for the "light" plaque formers. The following variables were determined: periodontal status, DFS, dietary habits, salivary secretion rate and buffer effect, S. mutans and lactobacillus counts in saliva, salivary content of IgA, lactoferrin, lactoperoxidase and lysozyme, saliva-induced aggregation of certain oral streptococci, gel electrophoresis of saliva, amino acid composition of saliva and the acquired pellicle and retention depth of the dentogingival area. Comparing the two groups of plaque formers, statistically significant differences were found for the following three variables: parotid saliva-induced aggregation of a strain of S. sanguis, content of glutamic acid in the acquired pellicle and retention depth of the dentogingival area for maxillary premolars. Large variations for all studied variables were found, both within and between the groups. Several factors may be involved in plaque formation and none of the studied variables alone could explain the large difference in the amount of plaque formed after 3 days between the "heavy" and "light" plaque formers.
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PMID:Rate of plaque formation--some clinical and biochemical characteristics of "heavy" and "light" plaque formers. 347 Sep 11

The proteolytic activities of 350 bacterial isolates from different sites (saliva, tongue, teeth, and mucosa) of the oral cavities of BALB/c mice were tested against different proteins found in saliva (immunoglobulins A, M, G, albumin, lysozyme, mucin, lactoferrin, and lactoperoxidase), some of which are considered to possess antibacterial activity. The results indicate that: (1) lysozyme, lactoferrin, and lactoperoxidase are hydrolyzed by from 46 to 70% of the indigenous flora of the oral cavities of BALB/c mice; (2) IgA and IgM appeared less sensitive to the proteolytic activities of these strains than did the other proteins tested; (3) the colonization of the oral cavity does not seem to be correlated with the proteolytic activity; and (4) the presence of specific Ig proteases is relatively scarce within this population.
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PMID:Proteolytic activity of bacteria isolated from the oral cavities of BALB/c mice toward salivary proteins. 347 43

This study was designed to compare various salivary parameters between smokers and non-smokers and to determine the influence of a nicotine-containing chewing gum (used to aid in quit-smoking efforts) upon these same parameters. At the baseline examination, subjects were assigned to one of three groups: non-smokers who did not utilize any gum, smokers provided a nicotine-containing gum, and smokers provided a placebo gum. Saliva was collected from all subjects and analyzed for acidogenicity and buffer pH as well as for levels of thiocyanate, lactoperoxidase, lysozyme, lactoferrin, and secretory IgA. After 15 weeks of gum usage, saliva was again collected from each subject and the identical analyses performed. Significant differences were observed between smokers and non-smokers with regard to three parameters: The saliva of smokers contained greater concentrations of thiocyanate and lower concentrations of lactoferrin, at the baseline examination and after the 15-week test period. In addition, the CO content of alveolar air was higher in smokers at both examination periods. In contrast, the use of the nicotine gum per se had no effect on any of the test parameters.
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PMID:Comparisons of various salivary parameters in smokers before and after the use of a nicotine-containing chewing gum. 385 4

There were several problems with the editorial on breastmilk and infection appearing in the May 30 Lancet. Of the antiinfective substances in human milk, lysozyme was omitted, as were the bifidus factor, the antistaphylococcus factor, antitoxins for neutralizing Vibrio cholerae and Escherichia coli, lactoperoxidase, and volatile fatty acids. Low pH and the exclusive specific bifidus bowel flora are all components of the same interacting antiinfective screen, as are macrophages and lymphocytes. Secretory IgA in breastmilk as a developmental bridging mechanism until the infant's intestine can secrete IgA itself at 3 months, is not recognized. The protective effect of human milk against death from diarrheal disease is well-known both in Europe and North America and in such disadvantaged communities as exist in the 3rd world. Clearly, this is related in part to a lack of contamination of human milk; the process is both passive and active. Recent studies show protective effects against infectious episodes in babies in well-to-do communities. The role of colostrum as an immunological bolus for the newborn is barely mentioned despite long known high levels of antibodies and the probability that neonatal diarrhea is often a colostrum deficiency syndrome. Doses of colostrum (5 mg/kg daily) reduce the incidence of endemic nursery neonatal E. coli diarrhea. The protective effects extend to other extraintestinal infections and to certain viral infections. There is no mention of the dyadic immunological interaction between mother and young baby, particularly through the proven "gut-mammary axis". The editorial concludes by damning with faint praise. For example, it is outdated, negative editorial revealing scant knowledge of the considerable published literature which documents the protective effect of breastfeeding against many alimentary and extraintestinal infections.
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PMID:Breast milk and infection. 611 83

Mouse myeloid leukemia M1 cells were induced to differentiate in vitro into macrophages and granulocytes by various inducers including ascitic fluid. Differentiated M1 cells induced with ascitic fluid expressed a differentiation-associated cell surface glycoprotein with a molecular weight of 180,000 (p180), which can be labeled by lactoperoxidase-catalyzed radioiodination or metabolic labeling with L-[14C]fucose. p180 was also induced by treatment with conditioned medium of hamster embryo cells, dexamethasone, dibutyryl cyclic adenosine 3':5'-monophosphate, and prostaglandin E1. Ascitic fluid, conditioned medium of hamster embryo cells, and dexamethasone induced all the differentiation-associated properties tested, whereas dibutyryl cyclic adenosine 3':5'-monophosphate and prostaglandin E1 induced lysozyme activity and adhesiveness to the substratum but not phagocytosis, locomotive activity, Fc receptors, or morphological changes. The adherent cells induced by dibutyryl cyclic adenosine 3':5'-monophosphate produced a large amount of p180, while the floating cells produced very little, but no difference was detected in the lysozyme activities of the two cell types. These results suggest that p180 is associated with cell-substratum adhesion of differentiated M1 cells.
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PMID:Expression of a cell surface glycoprotein (p180) related to cell-substratum adhesion during differentiation of mouse myeloid leukemia cells. 625 64

Oral candidiasis is a common problem, frequently presenting as a chronic recurring infection. Oral infection is a potential reservoir of organisms for severe, spreading, local disease and systemic disease in the compromised host. Nonspecific local oral factors in host defense include the epithelial barrier, flow or saliva, microbial interactions, antimicrobial constituents of saliva, lysozyme, lactoferrin, the lactoperoxidase system, levels of iron, and salivary glycoproteins. Immunoglobins are present in saliva, but their role is poorly understood. The activity of antibody against Candida on oral mucosal surfaces may not be mediated by complement and phagocyte activity. Specific antibodies against Candida may function by aggregating the organisms and preventing mucosal adherence of the fungi.
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PMID:Oral candidiasis: pathogenesis and host defense. 636 82

Examination of the localization of the dicarboxylate binding protein (DBP) in the cell envelope of Escherichia coli K12 reveals that this protein is present on the cell surface, and also in the inner and outer regions of the periplasmic space. The cell surface DBP is release by treating the cells with EDTA. This protein can be surface labeled by lactoperoxidase radioiodination, and by diazo[125I]iodosulfanilic acid in whole cells. It also binds tightly, but not covalently, to lipopolysaccharide. The DBP located in the outer region of the periplasmic space is released when the outer membrane is dissociated by EDTA-osmotic shock treatment. The DBP located in the inner region of the periplasmic space is released only when the EDTA-osmotic shocked cells are subjected to lysozyme treatment. At the moment, it is not certain whether this protein is bound to or trapped by the peptidoglycan network. This protein cannot be surface labeled in whole cells or in EDTA-osmotic shock treated cells; and it is not associated with lipopolysaccharide. Analysis of transport mutants indicates that these DBP are coded by the same gene.
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PMID:Localization of the dicarboxylate binding protein in the cell envelope of Escherichia coli K12. 678 Jan 68

Unstimulated and stimulated whole and unstimulated and stimulated parotid saliva were collected from subjected in three groups: I, control; II, seizure subjects ingesting phenytoin and without gingival overgrowth; III, seizure subjects receiving phenytoin and with grades 1 and 2 gingival overgrowth. Unstimulated whole saliva was obtained from mentally retarded donors with grade 3 phenytoin associated gingival overgrowth. The samples were analyzed for protein, lysozyme, lactoperoxidase, lactoferrin and aggregation capacity towards Streptococcus sanguis. Differences occurred in the salivary composition of patients ingesting phenytoin. No deficiencies of flow rate, protein or the specific proteins were found in subjects ingesting phenytoin. Instead, the only changes in these parameters were greater concentrations or secretion rates. Several differences occurred only in subjects with gingival overgrowth. These latter differences were prominent in unstimulated whole saliva. The data demonstrate changes in the oral cavity environment of patients ingesting phenytoin. These differences, however, do not have an obvious relationship to development of phenytoin associated gingival overgrowth. Some of the salivary changes occurred in patients undergoing therapy for seizures both with phenytoin and with other drugs. Increased amounts of unstimulated whole saliva components likely are due to excess tissue rather than a phenytoin effect on salivary gland secretions. In addition, most of the changes in salivary composition would not be expected to produce an environment the encourages plaque accumulation.
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PMID:Salivary composition, phenytoin ingestion and gingival overgrowth. 694 8


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