ABSTRACT
Enzyme immobilization appears as a remarkable technique to safely attach enzymes for several applications and cryogels stand as promising support materials to be used in such investigations. In this work, papain enzyme was immobilized onto an interpenetrating network obtained by cryogelation of N,N'-methylenebisacrylamide cross-linked 2-hydroxyethyl methacrylate and glutaraldehyde cross-linked chitosan. Cryogels were modified with -NH2 functionality and glutaraldehyde in order to attach papain covalently. Immobilization was carried out at 25 â in 0.1 M pH 7.0 phosphate buffer at 1.0 mg/ml enzyme concentration for 5 h. The amount of papain immobilized onto cryogel was calculated to be 15.2 ± 2.54 mg/g cryogel. Macroporous structure and surface area were determined by scanning electron microscopy and Brunauer-Emmett-Teller techniques, respectively. Energy dispersive X-ray analysis showed that papain was bound to the cryogel and cryogel structure was composed of 2-hydroxyethyl methacrylate, chitosan, and glutaraldehyde. Proteolytic activities of free and immobilized papain were measured using casein as substrate. Optimum pH values and temperatures were 8.0 and 65 â for free and immobilized enzymes and kinetic parameters were calculated at these conditions. Reusability and storage stability results indicated that immobilization enhanced the stability of papain compared to free form. Efficiency of immobilized papain was demonstrated by apple juice clarification study as an industrial use of the enzyme. Phenolic compound, protein, total soluble solid contents, and viscosity of apple juice before and after clarification were determined.
Subject(s)
Food Handling , Fruit and Vegetable Juices , Malus , Papain , Chitosan/chemistry , Cryogels/chemistry , Enzymes, Immobilized , Food Handling/methods , Hydrogen-Ion Concentration , Methacrylates/chemistry , Papain/chemistryABSTRACT
Molecularly imprinted PHEMAH cryogels were synthesized and used for purification of carbonic anhydrase from bovine erythrocyte. Cryogels were prepared with free radical cryopolymerization of 2-hydroxyethyl methacrylate and methacryloylamido histidine and characterized by swelling degree, macroporosity, FTIR, SEM, surface area and elemental analysis. Maximum carbonic anhydrase adsorption of molecularly imprinted PHEMAH cryogel was found to be 3.16 mg/g. Selectivity of the molecularly imprinted cryogel was investigated using albumin, hemoglobin, IgG, γ-globulin, and lysozyme as competitor proteins and selectivity ratios were found to be 15.26, 60.05, 21.88, 17.61, and 17.42, respectively. Carbonic anhydrase purity was demonstrated by SDS-PAGE and zymogram results.
Subject(s)
Carbonic Anhydrases/metabolism , Cryogels/chemical synthesis , Erythrocytes/metabolism , Histidine/analogs & derivatives , Molecular Imprinting/methods , Polymethacrylic Acids/chemical synthesis , Adsorption , Animals , Carbonic Anhydrases/isolation & purification , Cattle , Free Radicals/chemical synthesis , Hemoglobins/chemistry , Histidine/chemical synthesis , Histidine/chemistry , Immunoglobulin G/chemistry , Methacrylates/chemical synthesis , Methacrylates/chemistry , Muramidase/chemistry , Polymerization , Protein Binding , gamma-Globulins/chemistryABSTRACT
BACKGROUND: Considerable evidences have linked oxidative damage and cancer. In this article, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) activities, and malondialdehyde (MDA) and nitric oxide metabolites' levels (NO(x)) were investigated in patients with stomach cancer. METHODS: All measurments were done by spectrophotometric techniques. RESULTS: We observed a significant decrease in the activities of SOD and CAT in tumour tissues when compared with control tissues. The different of GSHPx activities and NO metabolite' levels were not statistically significant. MDA levels were significantly increased. CONCLUSIONS: We conclude that increased MDA levels and decreased antioxidant enzyme activities can be valuable parameters in assessing the possible risk of cancer.
Subject(s)
Adenocarcinoma/metabolism , Antioxidants/metabolism , Stomach Neoplasms/metabolism , Adult , Catalase/metabolism , Female , Glutathione Peroxidase/metabolism , Humans , Lipid Peroxidation , Male , Malondialdehyde/metabolism , Middle Aged , Nitric Oxide/metabolism , Superoxide Dismutase/metabolismABSTRACT
Previous studies on Cd-exposed pregnant animals have reported a Cd-Zn interaction that result in increased placental Cd levels and decreased placental Zn transport. In this study, placental Cd, Pb, Cu, and Zn status in pregnant women exposed to Cd and Pb through cigarette smoke was investigated. Placental tissues obtained from 30 nonsmokers (controls), 70 passive smokers, and 90 smokers were analyzed for Cu and Zn levels using an atomic absorption spectrophotometer and for Pb and Cd levels using an EG&G PARC Model 303A hanging mercury drop electrode. The result showed that whereas the placental Cd and Pb levels in smokers were higher that those of nonsmokers, Cu and zinc levels were lower in nonsmokers. These results imply that smoking during pregnancy could be harmful for both the mother and the fetus.
Subject(s)
Cadmium/metabolism , Copper/metabolism , Lead/metabolism , Placenta/metabolism , Smoking/metabolism , Zinc/metabolism , Female , Humans , Pregnancy , Spectrophotometry, Atomic , NicotianaABSTRACT
The aim of this study was to examine solvent-associated effects on blood cytokine levels, antioxidant enzyme activities, and malondialdehyde (MDA) concentration in house painters. Trace element (Cu and Zn) and nitrite and nitrate levels as well as protein concentrations in erythrocytes and serum were determined. Thirty male house painters and 30 male clerical workers were included in the study. There were 13 smokers and 17 nonsmokers in each group. Hemoglobin concentrations were significantly lower in house-painter blood compared to controls. House painters had significantly higher concentrations of erythrocyte protein (excluding hemoglobin), whereas no significant difference was observed between serum protein levels. Proinflammatory cytokine levels, such as tumor necrosis factor-alpha and interleukin-8, were significantly increased in house painters' sera. Interleukin-6 was below the detection limit of the assay in both groups. Interleukin-1beta and cytokine receptor interleukin 2R concentrations were not significantly affected. Furthermore, a three- to fourfold increase in nitrite and nitrate concentrations was found in house painters' sera. Serum superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities were significantly lower in house painters compared to controls. Malondialdehyde (MDA) concentration, a measure of lipid peroxidation, was found to be significantly elevated. In house painters, erythrocyte carbonic anhydrase and catalase activities were elevated approximately 11- fold and 2-fold, respectively. Zinc levels were significantly decreased in house painters' sera. Smoking was not found to be a major confounder for the association between solvent exposure and blood parameters.
