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Congo Red (congo + red)
Selected AbstractsDecolorization of simulated textile dye baths by crude laccases from Trametes hirsuta and Cerrena unicolorENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 3 2010Ulla Moilanen Abstract In this study crude laccases from the white-rot fungi Cerrena unicolor and Trametes hirsuta were tested for their ability to decolorize simulated textile dye baths. The dyes used were Remazol Brilliant Blue R (RBBR) (100,mg/L), Congo Red (12.5,mg/L), Lanaset Grey (75,mg/L) and Poly R-478 (50,mg/L). The effect of redox mediators on dye decolorization by laccases was also assessed. C. unicolor laccase was able to decolorize all the dyes tested. It was especially effective towards Congo Red and RBBR with 91 and 80% of color removal in 19.5,h despite the fact that simulated textile dye baths were used. Also Poly R-478 and Lanaset Grey were partially decolorized (69 and 48%, respectively). C. unicolor laccase did not need any mediators for removing the dyes. However, T. hirsuta laccase was only able to decolorize simulated Congo Red and RBBR dye baths (91 and 45%, respectively) in 19.5,h without mediators. When using mediators the decolorization capability was enhanced substantially, e.g. Poly R-478 was decolorized by 78% in 25.5,h. On the whole, both laccases showed potential to be used in industrial applications. [source] Biophysical studies of the development of amyloid fibrils from a peptide fragment of cold shock protein BFEBS JOURNAL, Issue 9 2000Deborah K. Wilkins The peptide CspB-1, which represents residues 1,22 of the cold shock protein CspB from Bacillus subtilis, has been shown to form amyloid fibrils when solutions containing this peptide in aqueous (50%) acetonitrile are diluted in water [M. Großet al. (1999) Protein Science8, 1350,1357] We established conditions in which reproducible kinetic steps associated with the formation of these fibrils can be observed. Studies combining these conditions with a range of biophysical methods reveal that a variety of distinct events occurs during the process that results in amyloid fibrils. A CD spectrum indicative of ,,structure is observed within 1 min of the solvent shift, and its intensity increases on a longer timescale in at least two kinetic phases. The characteristic wavelength shift of the amyloid-binding dye Congo Red is established within 30 min of the initiation of the aggregation process and corresponds to one of the phases observed by CD and to changes in the Fourier transform-infrared spectrum indicative of ,,structure. Short fibrillar structures begin to be visible under the electron microscope after these events, and longer, well-defined amyloid fibrils are established on a timescale of hours. NMR spectroscopy shows that there are no significant changes in the concentration of monomeric species in solution during the events leading to fibril formation, but that soluble aggregates too large to be visible in NMR spectra are present throughout the process. A model for amyloid formation by this peptide is presented which is consistent with these kinetic data and with published work on a variety of disease-related systems. These findings support the concept that the ability to form amyloid fibrils is a generic property of polypeptide chains, and that the mechanism of their formation is similar for different peptides and proteins. [source] Specificities of proteases for use in leather manufactureJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2006Farhad Foroughi Abstract Proteases are used in leather manufacture in the processes of soaking, unhairing and bating of hides and skins. However proteases can be relatively non-specific in their usage, and for improved efficacy of enzyme biocatalysis within the industry, an analysis of specific activities of enzymes towards skin proteins was undertaken. Most commercial proteases for soaking showed substantial activity against the substrates elastin,Congo Red and Azocoll but little or no activity against keratin,azure and hide powder black. Enzymes used for unhairing in conjunction with 30% of the usual concentration of sulfide to effect chemical unhairing showed moderate activity against all substrates tested (selected as representative of skin proteins), while proteases used in bating showed activity against Azocoll and elastin,Congo Red but had no keratinase activity and little activity against hide powder black. Bating proteases and soaking proteases displayed similar activities at pH 8. Microbes isolated in the screening of organisms from putrefied skins included one fungal and two bacterial isolates whose extracellular enzymes had efficient unhairing activity without the addition of sulfide. Enzyme activities for these proteases included high activity measured against Azocoll with little or no activity against elastin,Congo Red, keratin,azure and hide powder black. Neither elastase nor keratinase activities were determined as being essential for unhairing. Copyright © 2005 Society of Chemical Industry [source] A new method for assessing foliar uptake of fungicides using Congo Red as a tracerPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6 2001Ju-Hyun Yu Abstract In order to develop a new method for measuring foliar uptake of fungicides, Congo Red was selected as a tracer, and optimum procedures were established for washing, extracting and analyzing it and fungicides from leaf surfaces. Congo Red, a water-soluble dye, was not absorbed into cucumber or rice leaf, even in the presence of various surfactants, and was completely washable from leaf surfaces by aqueous acetonitrile solutions. Congo Red and fungicides in washings were quantified to calculate the amount of foliar uptake of the latter, by comparing the ratio to Congo Red. The optimum concentration of Congo Red in a formulation should be established in order to minimize its influence on fungicide uptake. Although Congo Red has proved to be useful with a conventional droplet application method, it will give more realistic and practical results with the spraying method used in the present study. © 2001 Society of Chemical Industry [source] Light propagation and scattering in porous silicon nanocomposite waveguidesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2005P. Pirasteh Abstract Planar waveguides have been achieved from oxidised porous silicon layers (OPS) which have been impregnated by solvents, Congo Red (CR) dye and poly(p-phenylene vinylene) (PPV) polymer. Optical loss has been investigated by a simple technique based on surface optical scattering measurements. Optical loss has been studied as a function of the wavelength, impregnation type and CR concentration. The main sources of attenuation, such as absorption, scattering from interface roughness, scattering from nano- crystallites and modification of the refractive indexes after filling are discussed. Optical loss measured at 0.633 µm is about 1.8 dB/cm for the OPS waveguides The optical loss decreases with wavelength. Otherwise, the optical loss increases with the concentration of Congo Red dye which is absorbent at this wavelength. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Aggregation characteristics of ovalbumin in ,-sheet conformation determined by spectroscopyBIOPOLYMERS, Issue 2 2002Raimon Sabaté Abstract Protein misfolding and aggregation are involved in a number of the so-called "conformational" diseases (e.g., transmissible spongiform encephalopathies and Alzheimer disease). The development of rational strategies to interfere with aggregation is a potential therapeutic approach that requires complete knowledge of the aggregation process. We studied the aggregation of ovalbumin in ,-sheet conformation using mainly the spectral changes in the spectra of two dyes (Congo Red and pinacyanol) caused by the aggregates. We assumed a linear model of polymerization that fit to the experimental data. The critical aggregation constant, concentration of half-aggregation, nucleation parameter, growth parameter, and number of aggregation and free energy changes (total and per residue) were determined as aggregation-related parameters. ,-Ovalbumin aggregates in a cooperative way. Moreover, the differences between such parameters obtained with Congo Red and pinacyanol suggest that each dye interacts with the protein in its own way. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 113,120, 2002 [source] Linear-dendritic ABA triblock copolymers as nanocarriersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007M. Adeli Abstract Linear-dendritic ABA triblock copolymers containing PEG were used for transport the small guest molecules such as 5,7-dibromo-8-hydoxy quinoline, ibuprofen, and Congo red. Nanocarriers containing guest molecules were soluble in water and in some of the organic solvents. Encapsulated guest molecules were soluble in some of the solvents, which they cannot be solved in them solely, for example, chloroform is a very poor solvent for Congo red, but encapsulated Congo red by nanocarriers is soluble in chloroform. The linear-dendritic copolymers/guest molecule complexes were stable at room temperature for about 10 months; during this time, guest molecules did not release from linear-dendritic copolymers/guest molecule complexes. The controlled release of guest molecules from linear-dendritic copolymers/guest molecule complexes in vitro conditions also was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 267,272, 2007 [source] Radioiodinated clioquinol as a biomarker for ,-amyloid: Zn2+ complexes in Alzheimer's diseaseAGING CELL, Issue 1 2006Carlos Opazo Summary Neocortical ,-amyloid (A,) aggregates in Alzheimer's disease (AD) are enriched in transition metals that mediate assembly. Clioquinol (CQ) targets metal interaction with A, and inhibits amyloid pathology in transgenic mice. Here, we investigated the binding properties of radioiodinated CQ ([125I]CQ) to different in vitro and in vivo Alzheimer models. We observed saturable binding of [125I]CQ to synthetic A, precipitated by Zn2+ (Kd = 0.45 and 1.40 nm for A,1-42 and A,1-40, respectively), which was fully displaced by free Zn2+, Cu2+, the chelator DTPA (diethylene triamine pentaacetic acid) and partially by Congo red. Sucrose density gradient of post-mortem AD brain indicated that [125I]CQ concentrated in a fraction enriched for both A, and Zn, which was modulated by exogenous addition of Zn2+ or DTPA. APP transgenic (Tg2576) mice injected with [125I]CQ exhibited higher brain retention of tracer compared to non-Tg mice. Autoradiography of brain sections of these animals confirmed selective [125I]CQ enrichment in the neocortex. Histologically, both thioflavine-S (ThS)-positive and negative structures were labeled by [125I]CQ. A pilot SPECT study of [123I]CQ showed limited uptake of the tracer into the brain, which did however, appear to be more rapid in AD patients compared to age-matched controls. These data support metallated A, species as the neuropharmacological target of CQ and indicate that this drug class may have potential as in vivo imaging agents for Alzheimer neuropathology. [source] Synthesis and 11C-labelling of (E,E)-1-(3,,4,-dihydroxystyryl)-4-(3,-methoxy-4,-hydroxystyryl) benzene for PET imaging of amyloid deposits,,JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 8 2002Yanming Wang Abstract Carboxylic acid derivatives of the amyloid-binding dye Congo red do not enter the brain well and are thus unable to serve as in vivo amyloid-imaging agents. A neutral amyloid probe, (E,E)-1-(3,,4,-dihydroxystyryl)-4-(3,-methoxy-4,-hydroxystyryl)benzene (3), devoid of any carboxylate groups has been designed and synthesized via a 12-step reaction sequence with a total yield of 30%. The unsymmetric compound 3 has also been labelled with C-11 via [11C]methyl iodide ([11C]CH3I) methylation of a symmetric 4,4,-dimesyl protected precursor followed by deprotection. Preliminary evaluation indicated that compound 3 selectively stained plaques and neurofibrillary tangles in post-mortem AD brain, and exhibited good binding affinity (Ki=38±8 nM) for A,(1,40) fibrils in vitro. In vivo pharmacokinetic studies indicated that [11C]3 exhibited higher brain uptake than its carboxylic acid analogs and good clearance from normal control mouse brain. [11C]3 also exhibited specific in vivo binding to pancreatic amyloid deposits in the NOR-beta transgenic mouse model. These results justify further investigation of 3 and similar derivatives as surrogate markers for in vivo quantitation of amyloid deposits. Copyright © 2002 John Wiley & Sons, Ltd. [source] Laryngeal presentation of systemic apolipoprotein A-I,derived amyloidosis,THE LARYNGOSCOPE, Issue 3 2009Aldert J. C. Hazenberg MD Abstract Objective: To study the clinical and pathological characteristics of two patients with laryngeal apolipoprotein A-I (apoA-I)-derived (AApoAI) amyloidosis with the apolipoprotein A-I variants Leu174Ser and Leu178Pro, respectively. The latter variant has not been associated with amyloid before. Study Design: Descriptive report of two patients who presented with laryngeal amyloid presumed to be of localized AL type, but in who further assessments demonstrated systemic amyloidosis. Methods: The larynx was examined by videolaryngostroboscopy. The voice was analyzed with the GRBAS system, phonation times, and phonetography. Laryngeal biopsies were stained with Congo red and analyzed immunohistochemically. Organ function was assessed and tissue involvement by amyloid further determined by rectal biopsy, abdominal fat tissue aspirate, and serum amyloid P component scintigraphy. Results: The appearance of the laryngeal amyloid was unusual in both patients, occurring as small, irregular floppy proliferations affecting the borders of both vocal folds. Amyloid was stained with antibodies to apoA-I and not with antibodies to immunoglobulin light chains. The 45-year-old woman with the previously described amyloidogenic apoA-I Leu174Ser variant had possible involvement by amyloid in joints, peripheral nerves, and heart. Whereas in the 67-year-old man with apoA-I Leu178Pro there was a clinical suggestion of autonomic and cardiac amyloid and histological corroboration of systemic amyloidosis in abdominal fat. Conclusions: Laryngeal symptoms may be the presenting feature of hereditary systemic AApoAI amyloidosis, and comprehensive investigations including apoA-I genotyping are warranted in patients who present with apparently localized laryngeal amyloidosis. The distinctive appearance of the amyloidotic vocal folds described here may further signal the possibility of hereditary AApoAI type. Laryngoscope, 119:608,615, 2009 [source] First report of an antifungal amidase from Peltophorum ptercoarpumBIOMEDICAL CHROMATOGRAPHY, Issue 5 2010Sze Kwan Lam Abstract A 60,kDa antifungal amidase was purified from Peltophorum ptercoarpum seeds using an isolation procedure that entailed ion-exchange chromatography on Q-Sepharose, ion-exchange chromatography on DEAE-cellulose and FPLC,gel filtration on Superdex 75. Unlike most other antifungal proteins isolated previously, it was adsorbed on Q-Sepharose and DEAE-cellulose. The isolated protein, designated as peltopterin, exhibited an N -terminal amino acid sequence closely resembling those of amidases. It exhibited amidase activity and digested iodoacetamide with an optimum pH and temperature at pH 9 and 50°C, respectively. It also hydrolyzed acrylamide and urea. It impeded mycelial growth in Rhizotonia solani with an IC50 of 0.65,,m. Chitin deposition at hyphal tips in R. solani was observed by staining with Congo red after incubation with peltopterin. Its antifungal activity was stable throughout pH 0,14 and 25,100°C. It potently inhibited HIV-1 reverse transcriptase with an IC50 of 27,nm. Copyright © 2009 John Wiley & Sons, Ltd. [source] Insight Into the Kinetic of Amyloid , (1,42) Peptide Self-Aggregation: Elucidation of Inhibitors' Mechanism of ActionCHEMBIOCHEM, Issue 17 2007Manuela Bartolini Dr. Abstract The initial transition of amyloid , (1,42) (A,42) soluble monomers/small oligomers from unordered/,-helix to a ,-sheet-rich conformation represents a suitable target to design new potent inhibitors and to obtain effective therapeutics for Alzheimer's disease. Under optimized conditions, this reliable and reproducible CD kinetic study showed a three-step sigmoid profile that was characterized by a lag phase (prevailing unordered/,-helix conformation), an exponential growth phase (increasing ,-sheet secondary structure) and a plateau phase (prevailing ,-sheet secondary structure). This kinetic analysis brought insight into the inhibitors' mechanism of action. In fact, an increase in the duration of the lag phase can be related to the formation of an inhibitor,A, complex, in which the non-amyloidogenic conformation is stabilized. When the exponential rate is affected exclusively, such as in the case of Congo red and tetracycline, then the inhibitor affinity might be higher for the pleated ,-sheet structure. Finally, by adding the inhibitor at the end of the exponential phase, the soluble protofibrils can be disrupted and the A, amyloidogenic structure can revert into monomers/small oligomers. Congo red and tetracycline preferentially bind to amyloid in the ,-sheet conformation because both decreased the slope of the exponential growth, even if to a different extent, whereas no effect was observed for tacrine and galantamine. Some very preliminary indications can be derived about the structural requirements for binding to nonamyloidogenic or ,-sheet amyloid secondary structure for the development of potent antiaggregating agents. On these premises, memoquin, a multifunctional molecule that was designed to become a drug candidate for the treatment of Alzheimer's disease, was investigated under the reported circular dichroism assay and its anti-amyloidogenic mechanism of action was elucidated. [source] Dystrophia Smolandiensis: a novel morphological picture of recurrent corneal erosionsACTA OPHTHALMOLOGICA, Issue 4 2010Björn Hammar Abstract. Purpose:, The aim of this study was to describe morphological changes in Dystrophia Smolandiensis, a corneal disease that is characterized by recurrent corneal erosive episodes and the formation of central corneal keloid-like opacities in approximately half of those affected. Methods:, The corneas of seven affected individuals were examined using in-vivo confocal microscopy. Specimens of one primary corneal graft, one regraft and one biopsied keloid-like region , all obtained from members of a large family with the disease , were re-examined with a light microscope. Sections were stained with Congo red and analysed immunohistochemically for fibronectin and S100A4. Results:, Light microscopic examination revealed epithelial hyperplasia, absence of Bowman's layer and subepithelial fibrosis. Fibronectin was expressed in the area of subepithelial fibrosis, and the keratocytes in this area generally expressed S100A4. The biopsy specimen stained positive for Congo red, suggesting an amyloid deposit. In-vivo confocal microscopy confirmed epithelial abnormalities, loss of Bowman's layer and significant alterations of the subbasal nerve plexus in affected individuals. Conclusion:, The morphological picture in Dystrophia Smolandiensis is novel for a condition dominated by recurrent corneal erosions at the clinical level. Although no single morphological feature unique to the disease could be found, the general morphological pattern of pathology (true keloid formation, absence of Bowman's layer, subepithelial fibrosis and abnormal subbasal nerves) probably reflects a novel phenotypic expression of the healing response to recurrent erosion of the corneal epithelium. However, the pathogenesis of Dystrophia Smolandiensis remains to be elucidated fully. [source] Spontaneous pancreatic islet amyloidosis in 40 baboonsJOURNAL OF MEDICAL PRIMATOLOGY, Issue 2 2002G.B. Hubbard Spontaneous amyloidosis occurs in many nonhuman primate species but remains difficult to diagnose and treat. Nonhuman primates continue to offer promise as animal models in which to study amyloidosis in humans. Amyloidosis was not diagnosed clinically but was found histologically in four male and 36 female baboons. The baboons averaged 18 years of age at death (range, 7,28 years). Clinical signs, if present, were hyperglycemia and cachexia. Blood glucose values were elevated in 12 of 30 baboons with available clinical pathology data. Four baboons had been clinically diagnosed as diabetic and three were treated with insulin. Amyloid was found in the islets of Langerhans of the pancreas in 40 baboons; 35 baboons had amyloid only in the islets of Langerhans. Amyloid was found in nonislet tissue of baboons as follows: five, nonislet pancreas; four, intestine and adrenal; three, kidney; two, prostate and spleen; and one each, lymph node, liver, gall bladder, stomach, tongue, urinary bladder, and salivary gland. Sections of paraffin-embedded tissues were evaluated for amyloid with hematoxylin and eosin (HE) and congo red (CR) staining, and using immunohistochemistry for human islet amyloid polypeptide (IAPP), calcitonin gene-related peptide (CGRP), glucagon, pancreatic polypeptide (PP), somatostatin (SS), and porcine insulin. Islet amyloid was positive with HE in 40 baboons, with CR in 39 baboons, and with IAPP and CGRP in 35 baboons. IAPP and CGRP only stained islet amyloid. PP, SS, glucagon, and porcine insulin did not stain amyloid. Islet amyloidosis in the baboon appears to be difficult to diagnose clinically, age-related, and similar to islet amyloidosis in other species. The baboon may be a good model for the study of islet amyloidosis in humans. [source] Conformations within soluble oligomers and insoluble aggregates revealed by resonance energy transferBIOPOLYMERS, Issue 4 2010Jyothi L. Digambaranath Abstract A fluorescently labeled 20-residue polyglutamic acid (polyE) peptide 20 amino acid length polyglutamic acid (E20) was used to study structural changes which occur in E20 as it co-aggregates with other unlabeled polyE peptides. Resonance energy transfer (RET) was performed using an o -aminobenzamide donor at the N-terminus and 3-nitrotyrosine acceptor at the C-terminus of E20. PolyE aggregates were not defined as amyloid, as they were nonfibrillar and did not bind congo red. Circular dichroism measurements indicate that polyE aggregation involves a transition from ,-helical monomers to aggregated ,-sheets. Soluble oligomers are also produced along with aggregates in the reaction, as determined through size exclusion chromatography. Time-resolved and steady-state RET measurements reveal four dominant E20 conformations: (1) a partially collapsed conformation (24 Å donor,acceptor distance) in monomers, (2) an extended conformation in soluble oligomers (>29 Å donor,acceptor distance), (3) a minor partially collapsed conformation (22 Å donor-acceptor distance) in aggregates, and (4) a major highly collapsed conformation (13 Å donor,acceptor distance) in aggregates. These findings demonstrate the use of RET as a means of determining angstrom-level structural details of soluble oligomer and aggregated states of proteins. © 2009 Wiley Periodicals, Inc. Biopolymers 93: 299,317, 2010. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] | ||||||||||||||||