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Zhang J, Shibata A, Ito M, Shuto S, Ito Y, Mannervik B, Abe H, Morgenstern R. Synthesis and characterization of a series of highly fluorogenic substrates for glutathione transferases, a general strategy. J Am Chem Soc 2011; 133:14109-19. [PMID: 21786801 DOI: 10.1021/ja205500y] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glutathione transferases (GSTs) are used in biotechnology applications as fusion partners for facile purification and are also overexpressed in certain tumors. Consequently, there is a need for sensitive detection of the enzymes. Here we describe a general strategy for the synthesis and characterization of novel fluorogenic substrates for GSTs. The substrates were synthesized by introducing an electrophilic sulfonamide linkage to fluorescent molecules containing an amino group [e.g., 2,4-dinitrobenzenesulfonamide (DNs) derivatives of coumarin, cresyl violet, and rhodamine]. The derivatives were essentially nonfluorescent, and upon GST catalyzed cleavage of the dinitrobenzenesulfonamide, free fluorophore is released (and 1-glutathionyl-2,4-dinitrobenzene + SO(2)). All the coumarin-, cresyl violet- and rhodamine-based fluorogenic probes turned out to be good substrates for most GSTs, especially for GSTA(1-1), in terms of strong fluorescence increases (71-1200-fold), high k(cat)/K(m) values (10(4)-10(7) M(-1) s(-1)) and significant rate enhancements (10(6)-10(9)-fold). The substrates were successfully applied to quantitate very low levels of GST activity in cell extracts and DNs-cresyl violet was also successfully applied to the imaging of microsomal MGST(1) activity in living cells. The cresyl violet stained cells retained their fluorescence after fixation, which is a very useful property. In summary, we describe a general and versatile strategy to generate fluorogenic GST substrates, some of them providing the most sensitive assays so far described for GSTs.
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Affiliation(s)
- Jie Zhang
- Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, Stockholm, Sweden
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Peoples MC, Karnes HT. Microfluidic immunoaffinity separations for bioanalysis. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 866:14-25. [PMID: 17869593 DOI: 10.1016/j.jchromb.2007.08.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 08/13/2007] [Accepted: 08/14/2007] [Indexed: 10/22/2022]
Abstract
Microfluidic devices often rely on antibody-antigen interactions as a means of separating analytes of interest from sample matrices. Immunoassays and immunoaffinity separations performed in miniaturized formats offer selective target isolation with minimal reagent consumption and reduced analysis times. The introduction of biological fluids and other complicated matrices often requires sample pretreatment or system modifications for compatibility with small-scale devices. Miniaturization of external equipment facilitates the potential for portable use such as in patient point-of-care settings. Microfluidic immunoaffinity systems including capillary and chip platforms have been assembled from basic instrument components for fluid control, sample introduction, and detection. The current review focuses on the use of immunoaffinity separations in microfluidic devices with an emphasis on pump-based flow and biological sample analysis.
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Affiliation(s)
- Michael C Peoples
- Department of Pharmaceutics, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0533, USA
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Breadmore MC, Henderson RD, Fakhari AR, Macka M, Haddad PR. Separation of Nile Blue-labelled fatty acids by CE with absorbance detection using a red light-emitting diode. Electrophoresis 2007; 28:1252-8. [PMID: 17367109 DOI: 10.1002/elps.200600580] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The separation of fatty acids derivatised with Nile Blue (NB) by CE with detection using a red light-emitting diode (LED) was examined. NB was selected as the derivatisation agent due to its high molar absorption coefficient of 76,000 M(-1) cm(-1) at 633 nm, making it well suited for sensitive absorbance detection using a red 635 nm LED. NB-labelled fatty acids were separated by both MEKC using SDS micelles, i-PrOH and n-BuOH and by NACE in a number of solvents including MeOH, EtOH and ACN. The sensitivity of NACE was superior to MEKC, with detection limits of 5x10(-7)-7x10(-7) M obtained for each acid, approximately 20 times lower than the MEKC method. The NACE detection limits are approximately 100 times lower than previous reports on the separation of fatty acids by CE using indirect absorbance detection, ten times lower than using indirect fluorescence detection and are inferior only to those obtained using precapillary derivatisation and direct fluorescence detection. The efficiency of the NACE method was also superior to MEKC and allowed the separation of unsaturated fatty acids to be examined, although it was not possible to baseline-resolve linoleic (C18:2) and linolenic (C18:3) acids in a reasonable time. The method was used to analyse the fatty acid profile of two edible oils, namely sunflower and sesame oils, after alkali hydrolysis, where it was possible to identify both the saturated and unsaturated fatty acids in each sample.
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Affiliation(s)
- Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
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Ho NH, Weissleder R, Tung CH. Development of water-soluble far-red fluorogenic dyes for enzyme sensing. Tetrahedron 2006. [DOI: 10.1016/j.tet.2005.10.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Dijana D, Olivera L, Zora N, Zdenka B, Verica MJ, Zoran Z, Dmitar D. Changes in myelinisation of neurons in different brain regions in progesterone-treated rats. ACTA VET-BEOGRAD 2003. [DOI: 10.2298/avb0306367d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Toyo’oka T. Fluorescent tagging of physiologically important carboxylic acids, including fatty acids, for their detection in liquid chromatography. Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(02)00398-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
We describe a new approach to making luminophores that display long emission wavelengths, long decay times, and high quantum yields. These luminophores are covalently linked pairs with a long-lifetime resonance-energy-transfer donor and a long-wavelength acceptor. The donor was a ruthenium (Ru) metal-ligand complex. The acceptor was the Texas Red. The donor and acceptor were covalently linked by polyproline spacers. The long-lifetime donor results in a long-lived component in the acceptor decay, which is due to RET. Importantly, the quantum yield of the luminophores approaches that of the higher quantum yield acceptor, rather than the lower quantum yield typical of metal-ligand complexes. The emission maxima and decay time of such tandem luminophores can be readily adjusted by selection of the donor, acceptor, and distance between them. Luminophores with these useful spectral properties can also be donor-acceptor pairs brought into close proximity by some biochemical association reaction. Luminophores with long-wavelength emission and long lifetimes can have numerous applications in biophysics, clinical diagnostics, DNA analysis, and drug discovery.
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Affiliation(s)
- B P Maliwal
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 21201, USA
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Lakowicz JR, Piszczek G, Kang JS. On the possibility of long-wavelength long-lifetime high-quantum-yield luminophores. Anal Biochem 2001; 288:62-75. [PMID: 11141307 PMCID: PMC6818246 DOI: 10.1006/abio.2000.4860] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We describe an approach to creating a new class of luminophores which display both long wavelength emissions exceeding 600 nm and long lifetimes. These luminophores are based on resonance energy transfer (RET) from a long lifetime donor to a short lifetime but long wavelength acceptor. We demonstrated the possibility of obtaining these desirable spectral properties using donors and acceptors noncovalently bound to DNA. The donor was a ruthenium (Ru) metal-ligand complex in which one of the diimine ligands intercalated into double-helix DNA. The acceptors were either nile blue, TOTO-3, or TO-PRO-3. Upon binding of the acceptor to donor-labeled DNA, we found that the acceptor quantum yield was remarkably enhanced so that the wavelength-integrated intensities of the donor and acceptor bound to DNA were many-fold greater than the intensity of the donor and acceptor alone when separately bound to DNA. The origin of this effect is efficient energy transfer from the donor. Under these conditions the effective overall quantum yield approaches that of the acceptor. Importantly, the increased quantum yield can be obtained while maintaining usefully long apparent acceptor lifetimes of 30 to 80 ns. The effect of an increased quantum yield from a low quantum yield donor may find use in assays to detect macromolecular binding interactions. These results suggest the synthesis of covalently linked donor-acceptor pairs with the desirable spectral properties of long wavelength emission, high quantum yield, and moderately long lifetimes for gated detection.
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Affiliation(s)
- J R Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201, USA
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Affiliation(s)
- D J Anderson
- Department of Chemistry, Cleveland State University, Ohio 44115, USA
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Nagaraj S, Rahavendran SV, Karnes HT. Visible diode laser induced fluorescence detection for capillary electrophoretic analysis of amantadine in human plasma following precolumn derivatization with Cy5.29.OSu. J Pharm Biomed Anal 1998; 18:411-20. [PMID: 10096835 DOI: 10.1016/s0731-7085(98)00054-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Visible diode laser induced fluorescence (VDLIF) detection (620-700 nm) has become important in bioanalysis due to the increased sensitivity and selectivity that can be achieved in biological matrices. A selective and sensitive capillary electrophoretic method employing VDLIF detection has been developed for the analysis of amantadine in plasma. Amantadine was extracted from plasma into toluene under alkaline conditions and the residue was derivatized with the far-red label Cy5.29.OSu. The reaction mixture was dried under nitrogen, reconstituted and then injected onto a laboratory constructed capillary electrophoresis system equipped with a laboratory constructed visible diode laser detector temperature tuned to oscillate at 647.8 nm. The selectivity of the technique was evaluated by demonstrating a lack of interfering peaks in extracts of blank plasma. A calibration curve ranging from 1.8 to 461.1 ng ml(-1) was shown to be linear. The precision and accuracy of the assay (n = 6) were determined to be within 17% R.S.D. and 15% difference from the nominal concentration respectively. The limits of detection for unextracted amantadine and for amantadine from the extracted concentrate from plasma were determined to be 9.5 fmol and 115 amol respectively.
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Affiliation(s)
- S Nagaraj
- Department of Pharmacy and Pharmaceutics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0533, USA
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Dorsey JG, Cooper WT, Siles BA, Foley JP, Barth HG. Liquid Chromatography: Theory and Methodology. Anal Chem 1998. [DOI: 10.1021/a1980022h] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- John G. Dorsey
- Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390
| | - William T. Cooper
- Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390
| | - Barbara A. Siles
- Department of Chemistry, College of William and Mary, Williamsburg, Virginia 23187-8795
| | - Joe P. Foley
- Department of Chemistry, Villanova University, Villanova, Pennsylvania 19085-1699
| | - Howard G. Barth
- Central Research and Development Department, E. I. du Pont de Nemours & Company, P.O. Box 80228, Experimental Station, Wilmington, Delaware 19880
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Rahavendran SV, Karnes HT. Visible diode laser-induced fluorescence detection of phenylacetic acid in plasma derivatized with Nile blue and using precolumn phase transfer catalysis. Anal Chem 1997; 69:3022-7. [PMID: 9253252 DOI: 10.1021/ac9700336] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study reports the application of Nile blue (NB), a farred oxazine label, as a precolumn derivatization reagent for the measurement of free levels of phenylacetic acid (PAA) in plasma. The measurement of PAA in psychiatric populations is important because it provides a marker for 2-phenylethylamine (PEA), which has been implicated in the pathogenesis of schizophrenia and major depression. PAA was derivatized with NB through an amide linkage in the presence of 2-chloro-1-methylpyridinium iodide (carboxylic acid activator, CMP) and triethylamine (base catalyst, TEA), respectively. The formation of the NB-PAA derivative was confirmed using normal phase and reversed phase thin-layer chromatography, reversed phase liquid chromatography, and electrospray mass spectrometry. The formation of the NB-PAA derivative was optimized using a sequential single factor approach. The optimal conditions for the formation and chromatographic separation of the derivative were determined to be 8.0 nmol/mL NB, 390 nmol/mL CMP, 2 mumol/mL TEA, a reaction time of 45 min, and a reaction temperature of 25 degrees C. This derivatization scheme was performed in a phase transfer catalysis mode that enabled the simultaneous extraction, preconcentration, and derivatization of the analyte in a single step. The limit of derivatization of PAA was determined to be 1.0 x 10(-9) M in phosphate-buffered saline, a PAA-free matrix. This derivatization was limited not by the kinetics of the reaction but by the chromatographic separation of the derivative from a side reaction product. The method was used to estimate endogenous free levels of PAA in human plasma samples. The levels of PAA in four sources of plasma were determined to be within 30-70 ng/mL using the method of standard addition and reflected levels that have been reported in the literature. The limit of detection of the derivative was determined to be 7.33 x 10(-11) M using a laboratory-constructed HPLC-VDLIF detector.
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Affiliation(s)
- S V Rahavendran
- Virginia Commonwealth University/Medical College of Virginia, Department of Pharmacy and Pharmaceutics, Richmond 23298-0533, USA
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