Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

P. gingivalis adheres to A. viscosus on mineral surfaces mimicking teeth. To study whether P. gingivalis proteases contribute to its binding, mutants of P. gingivalis deficient in proteases were compared with their parent strain and a P. gingivalis-type strain for their adherence to A. viscosus on saliva-coated hydroxyapatite by manipulating a radio-isotope binding assay. Adherence of P. gingivalis 2561 to A. viscosus was studied by tests of the effects of incubation temperature and known inhibitors or promoters of proteases. Controls were handled by the assay run in PBS buffer at 22 degrees C. Two mutants deficient in trypsin-like protease were found to be deficient in adherence (% attachment relative to control: 3.2 +/- 0.1% and 11.2 +/- 0.4%), while a collagenase-deficient mutant had an adherence score (51.6 +/- 8.4) closer to that of the parent strain (75.6 +/- 7.2%). Heating P. gingivalis at 70 degrees C decreased its subsequent adherence at 22 degrees C by 80%. Adherence decreased by 60% when the assay was run at 4 degrees C, but increased by 70% at 37 degrees C. Reducing agents (dithiothreitol, cysteine, and mercaptoethanol) enhanced P. gingivalis adherence by 50 to 60%. Protease inhibitors (BZMD, SBTI, TPCK, TLCK, CMPS, PMSF) decreased adherence by 10 to 50%. Also, Hg2+ and Zn2+ decreased adherence by 30 to 50%, and arginine decreased it by 50%. Most of these effects on P. gingivalis adherence were statistically significant (p less than 0.05). Analysis of these data suggests that P. gingivalis proteases may contribute to the cohesion of P. gingivalis and A. viscosus.
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PMID:Association of proteases of Porphyromonas (Bacteroides) gingivalis with its adhesion to Actinomyces viscosus. 184 87

The DNA repair enzyme uracil-DNA glycosylase from Mycoplasma lactucae (831-C4) was purified 1,657-fold by using affinity chromatography and chromatofocusing techniques. The only substrate for the enzyme was DNA that contained uracil residues, and the Km of the enzyme was 1.05 +/- 0.12 microM for dUMP containing DNA. The product of the reaction was uracil, and it acted as a noncompetitive inhibitor of the uracil-DNA glycosylase with a Ki of 5.2 mM. The activity of the enzyme was insensitive to Mg2+, Mn2+, Zn2+, Ca2+, and Co2+ over the concentration range tested, and the activity was not inhibited by EDTA. The enzyme activity exhibited a biphasic response to monovalent cations and to polyamines. The enzyme had a pI of 6.4 and existed as a nonspherical monomeric protein with a molecular weight of 28,500 +/- 1,200. The uracil-DNA glycosylase from M. lactucae was inhibited by the uracil-DNA glycosylase inhibitor from bacteriophage PBS-2, but the amount of inhibitor required for 50% inhibition of the mycoplasmal enzyme was 2.2 and 8 times greater than that required to cause 50% inhibition of the uracil-DNA glycosylases from Escherichia coli and Bacillus subtilis, respectively. Previous studies have reported that some mollicutes lack uracil-DNA glycosylase activity, and the results of this study demonstrate that the uracil-DNA glycosylase from M. lactucae has a higher Km for uracil-containing DNA than those of the glycosylases of other procaryotic organisms. Thus, the low G + C content of the DNA from some mollicutes and the A.T-biased mutation pressure observed in these organisms may be related to their decreased capacity to remove uracil residues from DNA.
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PMID:A mollicute (mycoplasma) DNA repair enzyme: purification and characterization of uracil-DNA glycosylase. 234 31

In newborn rat skin, disulfide bonds exist in the cell membrane of the stratum corneum and in the cytoplasm of the stratum granulosum. However, in the latter region, they can be detected after ethanol fixed epidermis remains for 2 weeks at 4 degrees C. Thus, the idea arose that the visualization of the disulfide bonds in the stratum granulosum may be caused by proteases. Therefore, the in situ effects by both activation and inhibition of epidermal proteases were examined in tissue sections. Cryostat sections which were fixed in cold ethanol (-20 degrees C, 98%) were incubated either in PBS, pH 7.4, containing 10mM 2-ME as a control or in an epidermal homogenate (15,000 x g supernatant fraction containing 2-ME) at 37 degrees C for 30 minutes and 4 hours, respectively, in order to activate the epidermal proteases and then reacted with NEM, 2-ME, and DACM in steps. Many minute fluorescent particles were seen in the stratum granulosum under both of the above conditions. However, with incubation in PBS without 2-ME, no fluorescent particles were seen. In addition, when the tissue was treated with NEM and zinc chloride before incubation, no fluorescent particles were seen. O-phenanthrolin remarkably inhibited the appearance of these fluorescent particles. In contrast, leupeptin and antipain only slightly inhibited the appearance of these fluorescent particles, and pepstatin and phenylmethylsulfonyl fluoride didn't inhibit at all. In general, as NEM and zinc chloride strongly inhibit thiol proteases, these findings suggest that presence of the minute fluorescent particles in the stratum granulosum could be due to the effects of proteases, especially thiol proteases.
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PMID:The substrate of epidermal proteases--effects of in situ activation of epidermal thiol proteases on stratum granulosum cells. 265 3

We tested the hypothesis that tumor necrosis factor-alpha (TNF-alpha) would be teratogenic in mice due in part to its effects on zinc metabolism. In Experiment 1, nonpregnant mice were injected with a single dose of TNF-alpha (40,000 U) or PBS and then received a 65Zn-labeled meal. Mice killed 10 h after TNF-alpha treatment had high liver 65Zn and low plasma 65Zn, compared with controls. In Experiment 2, gestation day 8 (GD 8) mice were injected with PBS or TNF-alpha and then received a 65Zn-labeled meal. Dams killed 10 h after TNF-alpha treatment had higher liver and kidney 65Zn and lower plasma and embryonic 65Zn accumulation than controls. In Experiment 3, TNF-alpha dosing from GD 7-12 was associated with high maternal liver Zn and metallothionein concentrations on GD 13 and a high frequency of exencephaly on GD 18. In Experiment 4, dams fed diets containing 4.5, 12.5 or 50.0 micrograms Zn/g were given PBS or TNF-alpha on GD 7-12. Gross fetal defects were not observed in the PBS-treated litters evaluated on GD 18. In contrast, TNF-alpha-treated litters were characterized by multiple defects, with the incidence and severity being highest in the low Zn diet group. In Experiment 5, embryos cultured in serum from TNF-alpha-treated animals exhibited a high frequency of defects; the developmental toxicity of this serum was ameliorated when it was supplemented with Zn. Thus, the developmental toxicity of TNF-alpha is due in part to its influence on Zn metabolism.
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PMID:Tumor necrosis factor-alpha alters maternal and embryonic zinc metabolism and is developmentally toxic in mice. 772 94

Serpulina hyodysenteriae produces an oxygen-stable heat-labile hemolysin that may be an important virulence factor in the pathogenesis of swine dysentery. We examined the effect of Ca2+, Co2+, Cu2+, Fe2+, Mg2+, Mn2+, Ni2+, and Zn2+ on the hemolytic activity of cell-free supernatant (CFS) from S. hyodysenteriae, isolate B204. Cells harvested from late logarithmic phase cultures were incubated in phosphate-buffered saline containing glucose and RNA-core (PBS-GR) with or without cations and the hemolytic activity of CFS obtained after successive 30 min incubation and washing cycles was determined. The addition of either ZnSO4 or CuSO4 to the PBS-GR caused complete inhibition of hemolytic activity after 3 cycles; other cations gave results similar to control extracts. Reduction in the concentration of Zn2+ in CFS by 60 to 80% after each incubation cycle and binding of Zn2+ by EDTA indicated that Zn2+ was associated with the cell fraction, and inhibition of hemolysin activity was specifically mediated by Zn2+. When the spirochetes were washed after incubation in the presence of ZnSO4 for 2 cycles and incubated in fresh PBS-GR without Zn2+, inhibition of hemolysin activity remained unchanged, indicating that the inhibitory effect of ZnSO4 was due to a direct action of ZnSO4 on the spirochetes. Since neither the viability of the spirochetes nor the activity of pre-formed hemolysin were affected by the presence of ZnSO4, the inhibitory effect of Zn2+ cations was attributed to reduced biosynthesis by viable S. hyodysenteriae cells rather than interference of Zn2+ cations with lysis of erythrocytes by the hemolysin. Transmission electron microscopic examination of spirochetes after incubation in PBS-GR containing ZnSO4 revealed clumping of ribosomes and clearing of cell cytoplasm.
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PMID:Effect of divalent cations on hemolysin synthesis by Serpulina (Treponema) hyodysenteriae: inhibition induced by zinc and copper. 780 26

In humans, recombinant hirudin (rHir), an anticoagulant protein, has a relatively short half-life (about 1 h). Therefore, a rHir formulation with sustained biological activity was previously proposed to result from complexing zinc salts and rHir (Zn-rHir). The purpose of this paper is to introduce and validate an in vitro release model for subcutaneous Zn-rHir formulations. In glass vials the formulations were suspended in agarose gel (2%) and coated with an extra layer of protein-free agarose. The agarose layers were covered with receiver solution, either buffered solutions (HEPES or PBS, pH 7.4) or human serum. To validate the release model and to demonstrate its potential to discriminate between different formulations, several commercial insulin and Zn-insulin formulations were also tested. The release profiles were evaluated by statistical moment analysis (mean times). Only in HEPES buffer was good discrimination between the investigated insulin formulations observed. The mean times of in vitro release of the insulin formulations and the proposed duration of their biological activities were in correlation. Low discrimination was found in PBS. For rHir, clear discrimination between the investigated rHir formulations was achieved in HEPES buffer, whereas low discrimination was found in PBS or in serum. The developed release model may be a sensitive in vitro test to assure the quality of subcutaneous insulin and rHir formulations, and may also be applicable to assess other slow-release protein and low molecular weight drug injectables.
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PMID:Sustained release of injectable zinc-recombinant hirudin suspensions: development and validation of in vitro release model. 965 30

The aim of this study was to determine the part played by the mitochondrial benzodiazepine receptor in cellular photosensitisation with the protoporphyrin IX precursor, delta-aminolaevulinic acid. Evaluation of the delta-aminolaevulinic acid-concentration dependence and kinetics of fluorescent protoporphyrin IX accumulation in monolayers of rat AR4 2J pancreatoma cells established a basis for assessing pharmacological modulation of the biosynthetic pathways for protoporphyrin IX production and photocytotoxicity. Iron chelation enhanced the accumulation of photo-active protoporphyrin IX whereas 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxam ide (PK11195), dipyridamole, or 7-(dimethylcarbamoloxy)-6-phenylpyrrolo-[2,1-d]benzothiazepi ne (DPB), competitive ligands of the mitochondrial benzodiazepine receptor, all diminished protoporphyrin IX accumulation, as did acifluorfen, a mitochondrial protoporphyrinogen oxidase inhibitor. In addition to protoporphyrin IX (Em(max): 630 nm), delta-aminolaevulinic acid-treated cells also generated a fluorophore of Em(max) 580 nm; this compound was identified as Zn-protoporphyrin IX. Mitochondrial benzodiazepine receptor ligands increased the formation of the zinc porphyrin whilst decreasing that of protoporphyrin IX. The involvement of the mitochondrial benzodiazepine receptor in the translocation of porphyrins and the formation of Zn-protoporphyrin IX have wide implications for the use of delta-aminolaevulinic acid in photodynamic therapy.
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PMID:A key role for the mitochondrial benzodiazepine receptor in cellular photosensitisation with delta-aminolaevulinic acid. 1102 Apr 79

Our previous work has shown that the lymphatic absorptions of lipids and lipid-soluble vitamins, retinol and alpha-tocopherol (alphaTP), are lowered markedly in rats fed a low-zinc (LZ) diet in parallel with lower lymphatic phospholipid outputs. Phosphatidylcholine (PC), when infused enterally, restored the absorptions of fat and retinol, but further lowered the absorption of alphaTP in rats fed the LZ diet. This study was conducted to determine whether a luminal infusion of lysophosphatidylcholine, a product of PC hydrolysis by pancreatic phospholipase A2 (PLA2), would simultaneously restore the absorptions of retinol and alphaTP in LZ rats. Rats were trained to consume two meals per day and were divided into two groups. One group was fed an AIN-93G diet containing a LZ (3.0 mg Zn/kg), and the other was fed the same diet, but containing adequate zinc (AZ; 30.0 mg Zn/kg) for 6 weeks. Rats with lymph cannula were infused at 3.0 ml/hr for 8 hr with a lipid emulsion containing retinol, alphaTP, and 14C-labeled triolein (14C-oleic acid) with or without 1-oleoyl-2-hydroxy phosphatidylcholine (lysoPC) in 24 ml of PBS (pH 6.5). When the lipid emulsion without lysoPC was infused, the absorptions of retinol and alphaTP were significantly lower in LZ rats (retinol, 13.2+/-1.5 nmol; alphaTP, 430.6+/-66.8 nmol) than in AZ rats (retinol, 18.2+/-1.0 nmol; alphaTP, 543.8+/-58.9 nmol). The lower absorptions of the vitamins in LZ rats occurred in parallel with a significant decrease in 14C-oleic acid absorption. When the emulsion containing lysoPC was infused, however, absorptions of the vitamins (retinol, 18.4+/-3.0 nmol; alphaTP, 777.2+/-92.1 nmol) in LZ rats were restored completely to the control levels (retinol, 20.4+/-2.8 nmol; alphaTP, 756.3+/-136.1 nmol). The results suggest that the luminal hydrolysis of PC to lysoPC by PLA2 may be impaired in LZ rats, resulting in impaired absorption of fat and the fat-soluble vitamins.
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PMID:Intraduodenal infusion of lysophosphatidylcholine restores the intestinal absorption of vitamins A and E in rats fed a low-zinc diet. 1136 27

Our previous study has shown that the lymphatic absorption of both fat and alpha-tocopherol (alphaTP) is lowered markedly in rats fed a low zinc diet, with a parallel decrease in lymphatic phospholipid (PL) output. This study was conducted to determine if enteral infusion of phosphatidylcholine (PC) could restore lymphatic absorption of fat and alphaTP in zinc-deficient rats. One group of rats was fed an AIN-93G diet containing 3 mg Zn/kg (low zinc; LZ) and the other was fed the same diet but containing 30 mg Zn/kg (adequate zinc; AZ). Rats were trained to consume two meals daily of equal amounts of food. At 6 wk, each rat with lymph fistula was infused at 3 mL/h with a lipid emulsion containing 3.6 &mgr;mol alphaTP and 565 &mgr;mol [carboxyl-14C]-triolein (14C-OA), with or without 40 &mgr;mol 1,2-dilinoleoyl-PC in 24 mL PBS at pH 6.4. The lymphatic absorptions of fat and alphaTP were determined by measuring 14C-radioactivity and alphaTP appearing in the mesenteric lymph collected hourly for 8 h. When the emulsion devoid of PC was infused, the absorptions of both 14C-OA (41 +/- 4% dose) and alphaTP (431 +/- 55 nmol) in LZ rats were significantly lower than in AZ rats (48 +/- 2% 14C-OA dose and 581 +/- 70 nmol alphaTP). When the emulsion containing PC was infused, the absorption of 14C-OA was restored rapidly to normal in LZ rats, along with a parallel increase in lymphatic PL output. However, PC infusion further lowered the absorption of alphaTP to 311 +/- 20 nmol/8 h in LZ rats and also lowered the absorption of alphaTP in AZ rats (347 +/- 48 nmol/8 h). The results demonstrate that low zinc intake results in impaired intestinal absorption of both alphaTP and fat. The findings also indicate that PC significantly improves the intestinal absorption of fat, but inhibits alphaTP absorption, suggesting that PC affects the intestinal absorption of alphaTP and fat via distinctly different mechanisms.
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PMID:Enteral infusion of phosphatidylcholine increases the lymphatic absorption of fat, but lowers alpha-tocopherol absorption in rats fed a low zinc diet* 1151 36

Oral tolerance is a specific immune unresponsiveness to food antigens to prevent hypersensitivity reactions. We investigated whether zinc deficiency affects oral tolerance. Rats were fed a control (C) or zinc-deficient (ZD) diet, or pair-fed (PF) to ZD rats for 28 d. Beginning on d 7, rats were administered ovalbumin (OVA) orally to induce tolerance, or PBS 3 times/wk, and were then immunized by OVA injection. The proliferation of mesenteric lymph node (MLN) and spleen lymphocytes after in vitro OVA stimulation and the delayed-type hypersensitivity were higher in OVA-fed ZD than in OVA-fed C rats and not different between OVA- and PBS-fed ZD rats, indicating a suppression of tolerance. Lymphocyte proliferation did not differ between PF and C rats. Expressions of cytokines involved in oral tolerance, i.e., interleukin (IL)-4, IL-10 and transforming growth factor-beta, were higher in OVA- than in PBS-fed C rats, but not in ZD rats. Apoptosis was higher in OVA- than in PBS-fed C rats but not different between OVA- and PBS-fed ZD rats. Inflammation and ulcerations that were not present in ZD rats on d 7 (ZD(7)) developed in OVA- or PBS-fed ZD rats. Compared with ZD(7) rats, tumor necrosis factor-alpha and cytokine-induced neutrophil chemoattractant were higher in OVA- and PBS-fed ZD rats, whereas interferon-gamma increased only in OVA-fed ZD rats. In conclusion, zinc deficiency suppresses oral tolerance through dysregulation of cytokine expression and lack of antigen-specific clonal deletion. We suggest that abrogation of tolerance may lead to development of mucosal inflammation and damage.
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PMID:Zinc deficiency suppresses the development of oral tolerance in rats. 1251 89


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