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101.
Joanna Kolodziejczyk Joanna Saluk-Juszczak Malgorzata M. Posmyk Krystyna M. Janas Barbara Wachowicz 《Central European Journal of Biology》2011,6(4):565-574
The present in vitro study was designed to examine the antioxidative activity of red cabbage anthocyanins (ATH) in the protection of blood plasma
proteins and lipids against damage induced by oxidative stress. Fresh leaves of red cabbage were extracted with a mixture
of methanol/distilled water/0.01% HCl (MeOH/H2O/HCl, 50/50/1, v/v/w). Total ATH concentration [μM] was determined with cyanidin 3-glucoside as a standard. Phenolic profiles
in the crude red cabbage extract were determined using the HPLC method. Plasma samples were exposed to 100 μM peroxynitrite
(ONOO−) or 2 mM hydrogen peroxide (H2O2) in the presence/absence of ATH extract (5–15 μM); oxidative alterations were then assessed. Pre-incubation of plasma with
ATH extract partly reduced oxidative stress in plasma proteins and lipids. Dose-dependent reduction of both ONOO− and H2O2-mediated plasma protein carbonylation was observed. ATH extract partly inhibited the nitrative action of ONOO−, and significantly decreased plasma lipid peroxidation caused by ONOO− or H2O2. Our results demonstrate that anthocyanins present in red cabbage have inhibitory effects on ONOO− and H2O2-induced oxidative stress in blood plasma components. We suggest that red cabbage ATH, as dietary antioxidants, should be
considered as potentially usable nutraceuticals in the prevention of oxidative stress-related diseases. 相似文献
102.
In vitro study of alginate–chitosan microcapsules: an alternative to liver cell transplants for the treatment of liver failure 总被引:7,自引:0,他引:7
Haque T Chen H Ouyang W Martoni C Lawuyi B Urbanska AM Prakash S 《Biotechnology letters》2005,27(5):317-322
The application of alginate–chitosan (AC) microcapsules to liver cell transplantation has not been previously investigated. In the current in vitro study, we have investigated the potential of AC microcapsules for the encapsulation of liver cells and show that the AC membrane supports the survival, proliferation and protein secretion by entrapped hepatocytes. The AC membrane provides cell immuno-isolation and has the potential for cell cryopreservation. The AC microcapsule has several advantages compared to more widely used alginate–poly-L-lysine (APA) microcapsules for the application of cell therapy. 相似文献
103.
Abate C Kolanos R Dukat M Setola V Roth BL Glennon RA 《Bioorganic & medicinal chemistry letters》2005,15(15):3510-3513
Optically active pyrrolidinylmethylindole analogs related in structure to the benzenesulfonyltryptamine 5-HT(6) receptor antagonist MS-245 were evaluated and their R-isomers were found to bind with affinity higher than their S-enantiomers. 相似文献
104.
Palczewska M Batta G Groves P Linse S Kuznicki J 《Protein science : a publication of the Protein Society》2005,14(7):1879-1887
Calretinin, a neuronal protein with well-defined calcium-binding properties, has a poorly defined function. The pH dependent properties of calretinin (CR), the N-terminal (CR I-II), and C-terminal (CR III-VI) domains were investigated. A drop in pH within the intracellular range (from pH 7.5 to pH 6.5) leads to an increased hydrophobicity of calcium-bound CR and its domains as reported by fluorescence spectroscopy with the hydrophobic probe 2-(p-toluidino)-6-naphthalenesulfonic acid (TNS). The TNS data for the N- and C-terminal domains of CR are additive, providing further support for their independence within the full-length protein. Our work concentrated on CR I-II, which was found to have hydrophobic properties similar to calmodulin at lower pH. The elution of CR I-II from a phenyl-Sepharose column was consistent with the TNS data. The pH-dependent structural changes were further localized to residues 13-28 and 44-51 using nuclear magnetic resonance spectroscopy chemical shift analysis, and there appear to be no large changes in secondary structure. Protonation of His 12 and/or His 27 side chains, coupled with calcium chelation, appears to lead to the organization of a hydrophobic pocket in the N-terminal domain. CR may sense and respond to calcium, proton, and other signals, contributing to conflicting data on the proteins role as a calcium sensor or calcium buffer. 相似文献
105.
Schwimmer C Lefebvre-Legendre L Rak M Devin A Slonimski PP di Rago JP Rigoulet M 《The Journal of biological chemistry》2005,280(35):30751-30759
In a previous study we have identified Fmc1p, a mitochondrial protein involved in the assembly/stability of the yeast F0F1-ATP synthase at elevated temperatures. The deltafmc1 mutant was shown to exhibit a severe phenotype of very slow growth on respiratory substrates at 37 degrees C. We have isolated ODC1 as a multicopy suppressor of the fmc1 deletion restoring a good respiratory growth. Odc1p expression level was estimated to be at least 10 times higher in mitochondria isolated from the deltafmc1/ODC1 transformant as compared with wild type mitochondria. Interestingly, ODC1 encodes an oxodicarboxylate carrier, which transports alpha-ketoglutarate and alpha-ketoadipate or any other transported tricarboxylic acid cycle intermediate in a counter-exchange through the inner mitochondrial membrane. We show that the suppression of the respiratory-growth-deficient fmc1 by the overexpressed Odc1p was not due to a restored stable ATP synthase. Instead, the rescuing mechanism involves an increase in the flux of tricarboxylic acid cycle intermediate from the cytosol into the mitochondria, leading to an increase in the alpha-ketoglutarate oxidative decarboxylation, resulting in an increase in mitochondrial substrate-level-dependent ATP synthesis. This mechanism of metabolic bypass of a defective ATP synthase unravels the physiological importance of intramitochondrial substrate-level phosphorylations. This unexpected result might be of interest for the development of therapeutic solutions in pathologies associated with defects in the oxidative phosphorylation system. 相似文献
106.
Zheng P Patel B McMenamin M Reddy SE Paprocki AM Schramm RD Latham KE 《Biology of reproduction》2004,70(5):1411-1418
107.
Zheng P Patel B McMenamin M Paprocki AM Schramm RD Nagl NG Wilsker D Wang X Moran E Latham KE 《Biology of reproduction》2004,70(5):1419-1427
108.
Marcyjaniak M Odintsov SG Sabala I Bochtler M 《The Journal of biological chemistry》2004,279(42):43982-43989
LAS enzymes are a group of metallopeptidases that share an active site architecture and a core folding motif and have been named according to the group members lysostaphin, D-Ala-D-Ala carboxypeptidase and sonic hedgehog. Escherichia coli MepA is a periplasmic, penicillin-insensitive murein endopeptidase that cleaves the D-alanyl-meso-2,6-diamino-pimelyl amide bond in E. coli peptidoglycan. The enzyme lacks sequence similarity with other peptidases, and is currently classified as a peptidase of unknown fold and catalytic class in all major data bases. Here, we build on our observation that two motifs, characteristic of the newly described LAS group of metallopeptidases, are conserved in MepA-type sequences. We demonstrate that recombinant E. coli MepA is sensitive to metal chelators and that mutations in the predicted Zn2+ ligands His-113, Asp-120, and His-211 inactivate the enzyme. Moreover, we present the crystal structure of MepA. The active site of the enzyme is most similar to the active sites of lysostaphin and D-Ala-D-Ala carboxypeptidase, and the fold is most closely related to the N-domain of sonic hedgehog. We conclude that MepA-type peptidases are LAS enzymes. 相似文献
109.
Fang X Ji H Kim SW Park JI Vaught TG Anastasiadis PZ Ciesiolka M McCrea PD 《The Journal of cell biology》2004,165(1):87-98
Using an animal model system and depletion-rescue strategies, we have addressed the requirement and functions of armadillo repeat gene deleted in velo-cardio-facial syndrome (ARVCF) and p120 catenins in early vertebrate embryogenesis. We find that xARVCF and Xp120 are essential to development given that depletion of either results in disrupted gastrulation and axial elongation, which are specific phenotypes based on self-rescue analysis and further criteria. Exogenous xARVCF or Xp120 cross-rescued depletion of the other, and each depletion was additionally rescued with (carefully titrated) dominant-negative RhoA or dominant-active Rac. Although xARVCF or Xp120 depletion did not appear to reduce the adhesive function of C-cadherin in standard cell reaggregation and additional assays, C-cadherin levels were somewhat reduced after xARVCF or Xp120 depletion, and rescue analysis using partial or full-length C-cadherin constructs suggested contributory effects on altered adhesion and signaling functions. This work indicates the required functions of both p120 and ARVCF in vertebrate embryogenesis and their shared functional interplay with RhoA, Rac, and cadherin in a developmental context. 相似文献
110.
Lobov S Wilczynska M Bergström F Johansson LB Ny T 《Journal of molecular biology》2004,344(5):1359-1368
Depending on the redox-status, the serpin plasminogen activator inhibitor type 2 (PAI-2) can exist in either a stable monomeric or polymerogenic form. The latter form, which spontaneously forms loop-sheet polymers, has an open beta-sheet A and is stabilized by a disulfide bond between C79 (in the CD-loop) and C161 (at the bottom of PAI-2). Reduction of this bond results in a closing of the beta-sheet A and converts PAI-2 to a stable monomeric form. Here we show that the stable monomeric and polymerogenic forms of PAI-2 are fully interconvertible, depending on redox-status of the environment. Our intramolecular distance measurements indicate that the CD-loop folds mainly on one side of the stable monomeric form of the inhibitor. However, the loop can translocate about 54A to the bottom of PAI-2 so that the C79-C161 disulfide bond can form under oxidizing conditions. We show also that the redox-active C79 can form a disulfide-link to the matrix protein vitronectin, suggesting that vitronectin can stabilize active PAI-2 in extracellular compartments. PAI-2 is therefore a rare example of a redox-sensitive protein for which the activity and polymerization ability are regulated by reversible disulfide bond formation leading to major translocation of a loop and significant conformational changes in the molecule. 相似文献