An extracellular lipase from Aureobasidium pullulans was obtained and purified with a specific activity of 17.7 U/mg of protein using ultrafiltration and a DEAE-Sepharose Fast Flow column. Characterization of the lipase indicated that it is a novel finding from the species A. pullulans. The molecular weight of the lipase was 39.5 kDa, determined by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited its optimum activity at 40 °C and pH of 7. It also showed a remarkable stability in some organic solutions (30%, v/v) including n-propanol, isopropanol, dimethyl sulfoxide (DMSO), and hexane. The catalytic activity of the lipase was enhanced by Ca²⁺ and was slightly inhibited by Mn²⁺ and Zn²⁺ at a concentration of 10 mmol/L. The lipase was activated by the anionic surfactant SDS and the non-ionic surfactants Tween 20, Tween 80, and Triton X-100, but it was drastically inhibited by the cationic surfactant cetyl trimethyl ammonium bromide (CTAB). Furthermore, the lipase was able to hydrolyze a wide variety of edible oils, such as peanut oil, corn oil, sunflower seed oil, sesame oil, and olive oil. Our study indicated that the lipase we obtained is a potential biocatalyst for industrial use.
Ascomycota/enzymology* ; Calcium ; Catalysis ; Corn Oil/metabolism* ; Detergents/chemistry* ; Enzyme Stability ; Fungal Proteins/chemistry* ; Glucans/chemistry* ; Hexanes/chemistry* ; Hydrogen-Ion Concentration ; Hydrolysis ; Industrial Microbiology ; Lipase/chemistry* ; Manganese/chemistry* ; Olive Oil/metabolism* ; Peanut Oil/metabolism* ; Sesame Oil/metabolism* ; Substrate Specificity ; Sunflower Oil/metabolism* ; Surface-Active Agents ; Temperature ; Zinc/chemistry*

Metal binding proteins or metallo-proteins are important for the stability of the protein and also serve as co-factors in various functions like controlling metabolism, regulating signal transport, and metal homeostasis. In structural genomics, prediction of metal binding proteins help in the selection of suitable growth medium for overexpression’s studies and also help in obtaining the functional protein. Computational prediction using machine learning approach has been widely used in various fields of bioinformatics based on the fact all the information contains in amino acid sequence. In this study, random forest machine learning prediction systems were deployed with simplified amino acid for prediction of individual major metal ion binding sites like copper, calcium, cobalt, iron, magnesium, manganese, nickel, and zinc.
Amino Acid Sequence* ; Binding Sites* ; Calcium ; Carrier Proteins ; Cobalt ; Computational Biology ; Copper ; Forests* ; Genomics ; Homeostasis ; Iron ; Machine Learning ; Magnesium ; Manganese ; Metabolism ; Nickel ; Zinc

BACKGROUNDManganese-enhanced magnetic resonance imaging (MEMRI) for visual pathway imaging via topical administration requires further research. This study investigated the permeability of the corneal epithelium and corneal toxicity after topical administration of Mn2+ to understand the applicability of MEMRI.

METHODSForty New Zealand rabbits were divided into 0.05 mol/L, 0.10 mol/L, and 0.20 mol/L groups as well as a control group (n = 10 in each group). Each group was further subdivided into epithelium-removed and epithelium-intact subgroups (n = 5 in each subgroup). Rabbits were given 8 drops of MnCl2in 5 min intervals. The Mn2+ concentrations in the aqueous and vitreous humors were analyzed using inductively coupled plasma-mass spectrometry at different time points. MEMRI scanning was carried out to image the visual pathway after 24 h. The corneal toxicity of Mn2+ was evaluated with corneal imaging and pathology slices.

RESULTSBetween the aqueous and vitreous humors, there was a 10 h lag for the peak Mn2+ concentration times. The intraocular Mn2+ concentration increased with the concentration gradients of Mn2+ and was higher in the epithelium-removed subgroup than that in the epithelium-intact subgroup. The enhancement of the visual pathway was achieved in the 0.10 mol/L and 0.20 mol/L epithelium-removed subgroups. The corresponding peak concentrations of Mn2+ were 5087 ± 666 ng/ml, 22920 ± 1188 ng/ml in the aqueous humor and 884 ± 78 ng/ml, 2556 ± 492 ng/ml in the vitreous body, respectively. Corneal injury was evident in the epithelium-removed and 0.20 mol/L epithelium-intact subgroups.

CONCLUSIONSThe corneal epithelium is a barrier to Mn2+, and the iris and lens septum might be another intraocular barrier to the permeation of Mn2+. An elevated Mn2+ concentration contributes to the increased permeation of Mn2+, higher MEMRI signal, and corneal toxicity. The enhancement of the visual pathway requires an effective Mn2+ concentration in the vitreous body.

Administration, Topical ; Animals ; Aqueous Humor ; drug effects ; metabolism ; Cornea ; drug effects ; metabolism ; Epithelium, Corneal ; drug effects ; metabolism ; Magnetic Resonance Imaging ; methods ; Male ; Manganese ; administration & dosage ; pharmacokinetics ; pharmacology ; Rabbits ; Visual Pathways ; drug effects ; Vitreous Body ; drug effects ; metabolism

OBJECTIVETo study the changes in the expression of divalent metal transporter 1 (DMT1) and ferroportin 1 (FP1) in the substantia nigra (SN) of rats with manganese-induced parkinsonism.

METHODSEighty Sprague-Dawley rats were randomly divided into four groups. Rats in the control group were injected intraperitoneally with saline solution. Rats in the low-dose, medium-dose, and high-dose groups were injected intraperitoneally with 5, 15, and 20 mg/kg MnC12 solution, respectively, for 16 weeks. Three behavioral tests were performed at the 16th week. The concentration of Mn2+ in the SN was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES), and the positive expression of tyrosine hydroxylase (TH) was measured by immunohistochemical staining to determine whether rats with manganese-induced parkinsonism were successfully produced. The expression of DMT1 and FP1 in SN was measured by immunohistochemical staining and fluorescent quantitative polymerase chain reaction.

RESULTSRats with manganese-induced parkinsonism were successfully produced using the above method. Compared with that in the control group, the concentrations of Mn2+ in the SN of rats exposed to 5, 15, and 20 mg/kg Mn2+ were significantly higher (1.72?0.33 vs 0.56 ± 0.20 µg/g, P<0.01; 2.92±0.77 vs 0.56±0.20 µg/g, P<0.01; 5.65±1.60 vs 0.56±0.20 µg/g, P<0.01). The mean ODs of TH-positive cells in the SN of rats exposed to 5, 15, and 20 mg/kg Mn+ were significantly lower than that in the control group (0.054±0.008 vs 0.109±0.019, P<0.01; 0.016±0.004 vs 0.109±0.019, P<0.01; 0.003±0.001 vs 0.109±0.019, P<0.01). Compared with that in the control group, the mean optical densities (ODs) of DMT1-positive cells in the SN of rats exposed to 15, and 20 mg/kg Mn2+ were significantly higher (0.062±0.004 vs 0.015±0.007, P<0.01; 0.116±0.064 vs 0.015±0.007, P<0.01). The mean ODs of FP1-positive cells in the SN of rats exposed to 5, 15, and 20 mg/kg Mn2+ were significantly lower than that in the control group (0.092±0.011 vs 0.306±0.081, P<0.01; 0.048±0.008 vs 0.306±0.081, P<0.01; 0.008±0.002 vs 0.306±0.081, P< 0.01). Rats exposed to 15 and 20 mg/kg Mn2+ had significantly higher expression of DMT1 mRNA in the SN than those in the control group (0.052±0.0126 vs 0.001±0.0004, P<0.05; 0.124±0.0299 vs 0.001±0.0004, P<0.05). However, rats exposed to 5, 15, and 20 mg/kg Mn2 had significantly lower expression of FP1 mRNA in the SN than those in the control group (0.059±0.0076 vs 0.162±0.0463, P<0.05; 0.033±0.0094 vs 0.162±0.0463, P< 0.05; 0.002±0.0007 vs 0.162±0.0463, P<0.05).

CONCLUSIONThe increased expression of DMT1 and reduced expression of FP1 may be involved in the processes of Mn2+ accumulation in the SN and dopaminergic neuron loss in rats with manganese-induced parkinsonism.

Animals ; Cation Transport Proteins ; metabolism ; Disease Models, Animal ; Manganese ; adverse effects ; Parkinsonian Disorders ; chemically induced ; metabolism ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Substantia Nigra ; metabolism ; physiopathology

OBJECTIVETo investigate the effects of enriched environment and impoverished environment on the learning and memory ability of manganese-exposed mice and the mechanism.

METHODSForty female Kunming mice were randomly and equally divided into 4 group: control group (CG), standard environment and manganese exposure group (SEG), enriched environment and manganese exposure group (EEG), and impoverished environment and manganese exposure group (IEG). The mouse model of manganese poisoning was established by intraperitoneal injection of manganese chloride. The learning and memory ability was tested by Morris water maze. The expression of cAMP response element-binding protein (CREB) in area CA1 of the hippocampus was measured by immunohistochemistry.

RESULTSIn place navigation test, the SEG had a significantly longer escape latency than the CG (P < 0.05), and the EEG had a significantly shorter escape latency than the SEG (P < 0.05); there was no significant difference in escape latency between IEG and SEG (P > 0.05). In spatial probe test, the EEG had a significantly greater number of platform crossings than the SEG (P < 0.05), and the IEG had a significantly smaller number of platform crossings than the SEG (P < 0.05). The expression of CREB in area CA1 of the hippocampus was significantly lower in IEG and SEG than in CG (P < 0.05), and it was significantly higher in EEG than in SEG (P < 0.05).

CONCLUSIONIn the enriched environment, the learning and memory ability of manganese-exposed mice can be improved, which may be due to the increased expression of CREB in the hippocampus.

Animals ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Disease Models, Animal ; Environment ; Female ; Hippocampus ; drug effects ; metabolism ; Learning ; drug effects ; Manganese Poisoning ; metabolism ; Memory ; drug effects ; Mice

D-psicose 3-epimerase (DPEase) is demonstrated to be useful in the bioproduction of D-psicose, a rare hexose sugar, from D-fructose, found plenty in nature. Clostridium cellulolyticum H10 has recently been identified as a DPEase that can epimerize D-fructose to yield D-psicose with a much higher conversion rate when compared with the conventionally used DTEase. In this study, the crystal structure of the C. cellulolyticum DPEase was determined. The enzyme assembles into a tetramer and each subunit shows a (β/α)(8) TIM barrel fold with a Mn(2+) metal ion in the active site. Additional crystal structures of the enzyme in complex with substrates/products (D-psicose, D-fructose, D-tagatose and D-sorbose) were also determined. From the complex structures of C. cellulolyticum DPEase with D-psicose and D-fructose, the enzyme has much more interactions with D-psicose than D-fructose by forming more hydrogen bonds between the substrate and the active site residues. Accordingly, based on these ketohexose-bound complex structures, a C3-O3 proton-exchange mechanism for the conversion between D-psicose and D-fructose is proposed here. These results provide a clear idea for the deprotonation/protonation roles of E150 and E244 in catalysis.
Binding Sites ; Biocatalysis ; Catalytic Domain ; Clostridium cellulolyticum ; enzymology ; Hexoses ; chemistry ; Manganese ; chemistry ; Protein Structure, Quaternary ; Racemases and Epimerases ; chemistry ; metabolism ; Substrate Specificity

OBJECTIVETo explore the effect of MnCl(2) on the mitochondrial function of human lung cells, and to study the changes of protein expression level of nuclear respiratory factor-1 (NRF-1) in mitochondrial dysfunction induced by MnCl(2).

METHODSThe effects of MnCl(2) on cell survival rate were assessed by the reductions of tetrazolium dye (MTT) in cultured cell lines 16HBE and A549 cells. All tested16HBE and A549 cells were incubated with different concentrations of MnCl(2). The permeability transition pore (PTP) of mitochondria, mitochondrial membrane potential and the inhibition rate of mitochondrial enzymes as indicators of mitochondrial damage were measured by fluorescent spectrometry and MTT assay, respectively. Apoptosis was determined by flow cytometry. Protein levels of NRF-1 and mtTFA were measured by Western blot assay.

RESULTSMnCl(2) decreased the survival rate of the two cell lines. The IC(50) of 16HBE and A549 cells were 1.91 mmol/L and 1.98 mmol/L, respectively. MnCl(2) caused a concentration-dependent decrease of mitochondrial enzymes and the inhibition rate of mitochondrial enzymes of the two cell lines induced by 1.00 mmol/L MnCl(2) were (52.8 ± 5.4)% and (50.6 ± 2.2)%, respectively. The PTP opening increased in MnCl(2)-treated cells in a dose- and time-dependent manner. Compared with the control group, mitochondrial membrane potential in the two cell lines was decreased by MnCl(2), by (7.9 ± 3.0)%, (26.2 ± 2.2)% and (27.8 ± 4.1)% in the 16HBE cells, and (4.7 ± 1.0)%, (14.9 ± 2.4)% and (27.5 ± 1.2)% in the A549 cells. Increased apoptosis rates of the two cell lines were induced by 1.00 mmol/L MnCl(2), (12.3 ± 1.9)% and (6.0 ± 0.4)%, respectively. The results of Western blot assay revealed that the protein levels of NRF-1 and mtTFA were decreased in manganese-treated cells in a dose-dependent manner, with a significant difference compared with that of the control cells (P < 0.05).

CONCLUSIONMnCl(2) induces mitochondrial dysfunction in 16HBE and A549 cells, and decreases the expression level of nuclear respiratory factor-1 (NRF-1), indicating that NRF-1 may play an important role in mitochondrial dysfunction.

Apoptosis ; drug effects ; Bronchi ; cytology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cells, Cultured ; Chlorides ; administration & dosage ; toxicity ; DNA-Binding Proteins ; metabolism ; Dose-Response Relationship, Drug ; Epithelial Cells ; cytology ; metabolism ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Manganese Compounds ; administration & dosage ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria ; drug effects ; physiology ; Mitochondrial Membrane Transport Proteins ; drug effects ; Mitochondrial Proteins ; metabolism ; Nuclear Respiratory Factor 1 ; metabolism ; Transcription Factors ; metabolism

Little is known about hair mineral status in fibromyalgia patients. This study evaluated the characteristics of hair minerals in female patients with fibromyalgia compared with a healthy reference group. Forty-four female patients diagnosed with fibromyalgia according to the American College of Rheumatology criteria were enrolled as the case group. Age- and body mass index-matched data were obtained from 122 control subjects enrolled during visit for a regular health check-up. Hair minerals were analyzed and compared between the two groups. The mean age was 43.7 yr. General characteristics were not different between the two groups. Fibromyalgia patients showed a significantly lower level of calcium (775 microg/g vs 1,093 microg/g), magnesium (52 microg/g vs 72 microg/g), iron (5.9 microg/g vs 7.1 microg/g), copper (28.3 microg/g vs 40.2 microg/g) and manganese (140 ng/g vs 190 ng/g). Calcium, magnesium, iron, and manganese were loaded in the same factor using factor analysis; the mean of this factor was significantly lower in fibromyalgia group in multivariate analysis with adjustment for potential confounders. In conclusion, the concentrations of calcium, magnesium, iron, and manganese in the hair of female patients with fibromyalgia are lower than of controls, even after adjustment of potential confounders.
Adult ; Body Height ; Body Mass Index ; Calcium/analysis ; Female ; Fibromyalgia/*metabolism ; Hair/*chemistry ; Humans ; Iron/analysis ; Magnesium/analysis ; Manganese/analysis ; Metals/*analysis ; Middle Aged

OBJECTIVETo probe the effect of sodium para-aminosalicylate (PAS-Na) on concentration of amino acid neurotransmitters including glutamate (Glu), glutamine (Gln), glycine (Gly) and gamma-aminobutyric acid (GABA) in basal ganglia of subacute manganese (Mn)-exposed rats.

METHODSForty Sprague-Dawley male rats were randomly divided into the control, Mn-exposed, low dose PAS-Na (L-PAS) and high dose PAS-Na (H-PAS) groups. Rats in experiment groups received daily intraperitoneally injections of manganese chloride (MnCl₂ · 4H₂O, 15 mg/kg), while rats in control group received daily intraperitoneally injections of normal saline (NS), all at 5 days/week for 4 weeks. Then the rats in PAS groups followed by a daily subcutaneously dose of PAS-Na (100 and 200 mg/kg as the L-PAS and H-PAS groups, respectively) for another 3 and 6 weeks; while the rats in Mn-exposed and control group received NS. The concentrations of Glu, Gln, Gly and GABA in basal ganglia of rat was detected by the high performance liquid chromatography fluorescence detection technique.

RESULTSAfter treating with PAS-Na for 3 weeks, the concentration of Gly in the Mn-exposed rats decreased to (0.165 ± 0.022) µmol/L (control = (0.271 ± 0.074) µmol/L, Mn vs control, t = 4.65, P < 0.05). After the further 6-week therapy with PAS-Na, the concentrations of Glu, Gln, Gly in the Mn-exposed rats were lower than those of the control rats ((0.942 ± 0.121), (0.377 ± 0.070), (0.142 ± 0.048), (1.590 ± 0.302), (0.563 ± 0.040), (0.247 ± 0.084) µmol/L; t = 7.72, 5.85, 4.30, P < 0.05); and also lower than in L-PAS and H-PAS groups, whose concentrations were separately (1.268 ± 0.124), (1.465 ± 0.196), (0.497 ± 0.050), (0.514 ± 0.103), (0.219 ± 0.034) µmol/L (L-PAS Glu and Gln vs Mn, t = 3.87, 3.77, P < 0.05; H-PAS Glu, Gln and Gly vs Mn, t = 6.78, 4.70, 3.42, P < 0.05).

CONCLUSIONThe toxic effect of manganese on Glu, Gln and Gly in basal ganglia of Mn-exposed rats is obvious, especially appears earlier on Gly. The toxic effect still continues to develop when relieved from the exposure. PAS-Na may play an antagonism role in toxic effect of manganese on concentration of Glu, Gln and Gly in basal ganglia of Mn-exposed rats.

Amino Acids ; metabolism ; Animals ; Basal Ganglia ; drug effects ; metabolism ; Glutamic Acid ; metabolism ; Male ; Manganese ; toxicity ; Neurotransmitter Agents ; metabolism ; Rats ; Rats, Sprague-Dawley ; Sodium Salicylate ; pharmacology ; gamma-Aminobutyric Acid ; metabolism

The effects of reaction temperature, ethanol concentration and weight hourly space velocity (WHSV) on the ethylene production from ethanol dehydration using zinc, manganese and cobalt modified HZSM-5 catalyst were investigated by response surface methodology (RSM). The results showed that the most significant effect among factors was reaction temperature and the factors had interaction. The optimum conditions were found as 34.4% ethanol concentration, 261.3 0 degrees C of reaction temperature and 1.18 h(-1) of WHSV, under these conditions the yield of ethylene achieved 98.69%.
Catalysis ; Cobalt ; chemistry ; Dehydration ; Ethanol ; chemistry ; Ethylenes ; chemistry ; metabolism ; Manganese ; chemistry ; Zeolites ; chemistry ; Zinc ; chemistry