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Wang J, Jin Y, Li M, Liu S, Lo KKW, Zhao Q. Time-Resolved Luminescent Sensing and Imaging for Enzyme Catalytic Activity Based on Responsive Probes. Chem Asian J 2022; 17:e202200429. [PMID: 35819359 DOI: 10.1002/asia.202200429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/11/2022] [Indexed: 11/07/2022]
Abstract
Enzymes, as a kind of biomacromolecules, play an important role in many physiological processes and relate directly to various diseases. Developing an efficient detection method for enzyme activity is important to achieve early diagnosis of enzyme-relevant diseases and high throughput screening of potential enzyme-relevant drugs. Time-resolved luminescence assay provide a high accuracy and signal-to-noise ratios detection methods for enzyme activity, which has been widely used in high throughput screening of enzyme-relevant drugs and diagnosis of enzyme-relevant diseases. Inspired by these advantages, various responsive probes based on metal complexes and metal-free organic compounds have been developed for time-resolved bioimaging and biosensing of enzyme activity owing to their long luminescence lifetimes, high quantum yields and photostability. In this review, we comprehensively reviewed metal complex- and metal-free organic compound-based responsive probes applied to detect enzyme activity through time-resolved imaging, including their design strategies and sensing principles. Current challenges and future prospects in this rapidly growing field are also discussed.
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Affiliation(s)
- Jiawei Wang
- Nanjing University of Posts and Telecommunications, Institute of Advanced Materials, 9 Wenyuan Road, 210023, Nanjing, CHINA
| | - Yibiao Jin
- Nanjing University of Posts and Telecommunications, Institute of Advanced Materials, 9 Wenyuan Road, 210023, Nanjing, CHINA
| | - Mingdang Li
- Nanjing University of Posts and Telecommunications, Institute of Advanced Materials, 9 Wenyuan Road, 210023, Nanjing, CHINA
| | - Shujuan Liu
- Nanjing University of Posts and Telecommunications, Institute of Advanced Materials, 9 Wenyuan Road, 210023, Nanjing, CHINA
| | - Kenneth Kam-Wing Lo
- City University of Hong Kong, Department of Chemistry, Tat Chee Avenue, Hong Kong, CHINA
| | - Qiang Zhao
- Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, 210023, Nanjing, CHINA
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2
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Nilam M, Hennig A. Enzyme assays with supramolecular chemosensors - the label-free approach. RSC Adv 2022; 12:10725-10748. [PMID: 35425010 PMCID: PMC8984408 DOI: 10.1039/d1ra08617k] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 03/30/2022] [Indexed: 12/20/2022] Open
Abstract
Enzyme activity measurements are essential for many research areas, e.g., for the identification of inhibitors in drug discovery, in bioengineering of enzyme mutants for biotechnological applications, or in bioanalytical chemistry as parts of biosensors. In particular in high-throughput screening (HTS), sensitive optical detection is most preferred and numerous absorption and fluorescence spectroscopy-based enzyme assays have been developed, which most frequently require time-consuming fluorescent labelling that may interfere with biological recognition. The use of supramolecular chemosensors, which can specifically signal analytes with fluorescence-based read-out methods, affords an attractive and label-free alternative to more established enzyme assays. We provide herein a comprehensive review that summarizes the current state-of-the-art of supramolecular enzyme assays ranging from early examples with covalent chemosensors to the most recent applications of supramolecular tandem enzyme assays, which utilize common and often commercially available combinations of macrocyclic host molecules (e.g. cyclodextrins, calixarenes, and cucurbiturils) and fluorescent dyes as self-assembled reporter pairs for assaying enzyme activity.
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Affiliation(s)
- Mohamed Nilam
- Department of Biology/Chemistry, Center for Cellular Nanoanalytics (CellNanOs), Universität Osnabrück Barbarastr. 7 D-49076 Osnabrück Germany
| | - Andreas Hennig
- Department of Biology/Chemistry, Center for Cellular Nanoanalytics (CellNanOs), Universität Osnabrück Barbarastr. 7 D-49076 Osnabrück Germany
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Hennig A, Nau WM. Interaction of Cucurbit[7]uril With Protease Substrates: Application to Nanosecond Time-Resolved Fluorescence Assays. Front Chem 2020; 8:806. [PMID: 33134264 PMCID: PMC7511663 DOI: 10.3389/fchem.2020.00806] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 07/31/2020] [Indexed: 01/04/2023] Open
Abstract
We report the use of the macrocyclic host cucurbit[7]uril (CB7) as a supramolecular additive in nanosecond time-resolved fluorescence (Nano-TRF) assays for proteases to enhance the discrimination of substrates and products and, thereby, the sensitivity. A peptide substrate was labeled with 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) as a long-lived (>300 ns) fluorescent probe and 3-nitrotyrosine was established as a non-fluorescent fluorescence resonance energy transfer (FRET) acceptor that acts as a “dark quencher.” The substrate was cleaved by the model proteases trypsin and chymotrypsin and the effects of the addition of CB7 to the enzyme assay mixture were investigated in detail using UV/VIS absorption as well as steady-state and time-resolved fluorescence spectroscopy. This also allowed us to identify the DBO and nitrotyrosine residues as preferential binding sites for CB7 and suggested a hairpin conformation of the peptide, in which the guanidinium side chain of an arginine residue is additionally bound to a vacant ureido rim of one of the CB7 hosts.
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Affiliation(s)
- Andreas Hennig
- Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Bremen, Germany.,Institute of Chemistry of New Materials, School of Biology/Chemistry, Universität Osnabrück, Osnabrück, Germany.,Center of Cellular Nanoanalytics (CellNanOs), Universität Osnabrück, Osnabrück, Germany
| | - Werner M Nau
- Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Bremen, Germany
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Non-canonical amino acids bearing thiophene and bithiophene: synthesis by an Ugi multicomponent reaction and studies on ion recognition ability. Amino Acids 2017; 49:921-930. [DOI: 10.1007/s00726-017-2392-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 02/01/2017] [Indexed: 01/11/2023]
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Nilam M, Gribbon P, Reinshagen J, Cordts K, Schwedhelm E, Nau WM, Hennig A. A Label-Free Continuous Fluorescence-Based Assay for Monitoring Ornithine Decarboxylase Activity with a Synthetic Putrescine Receptor. SLAS DISCOVERY 2017; 22:906-914. [PMID: 28346093 DOI: 10.1177/2472555216689288] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Polyamines play an important role in cell growth, differentiation, and cancer development, and the biosynthetic pathway of polyamines is established as a drug target for the treatment of parasitic diseases, neoplasia, and cancer chemoprevention. The key enzyme in polyamine biosynthesis is ornithine decarboxylase (ODC). We report herein an analytical method for the continuous fluorescence monitoring of ODC activity based on the supramolecular receptor cucurbit[6]uril (CB6) and the fluorescent dye trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (DSMI). CB6 has a significantly higher binding constant to the ODC product putrescine (>107 M-1) than to the substrate L-ornithine (340 M-1). This enables real-time monitoring of the enzymatic reaction through a continuous fluorescence change caused by dye displacement from the macrocycle by the formed product, which allowed a straightforward determination of enzyme kinetic parameters ( kcat = 0.12 s-1 and KM = 24 µM) and inhibition constants of the two ODC inhibitors α-difluoromethylornithine (DFMO) and epigallocatechin gallate (EGCG). The potential for high-throughput screening (HTS) was demonstrated by excellent Z' factors (>0.9) in a microplate reader format, and the sensitivity of the assay is comparable to or better than most established complementary methods, which invariably have the disadvantage of not being compatible with direct implementation and upscaling to HTS format in the drug discovery process.
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Affiliation(s)
- Mohamed Nilam
- 1 Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | | | | | - Kathrin Cordts
- 3 Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- 4 German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Edzard Schwedhelm
- 3 Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- 4 German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Werner M Nau
- 1 Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Andreas Hennig
- 1 Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
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Sloniec J, Resch-Genger U, Hennig A. Photophysics and Release Kinetics of Enzyme-Activatable Optical Probes Based on H-Dimerized Fluorophores on Self-Immolative Linkers. J Phys Chem B 2013; 117:14336-44. [DOI: 10.1021/jp409388b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jagoda Sloniec
- BAM Federal Institute for Materials Research and Testing, D-12489 Berlin, Germany
| | - Ute Resch-Genger
- BAM Federal Institute for Materials Research and Testing, D-12489 Berlin, Germany
| | - Andreas Hennig
- BAM Federal Institute for Materials Research and Testing, D-12489 Berlin, Germany
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Ghale G, Kuhnert N, Nau WM. Monitoring Stepwise Proteolytic Degradation of Peptides by Supramolecular Domino Tandem Assays and Mass Spectrometry for Trypsin and Leucine Aminopeptidase. Nat Prod Commun 2012. [DOI: 10.1177/1934578x1200700315] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A label-free optical detection method has been designed that allows direct monitoring of enzymatic peptide digestion in vitro. The method is based on the addition of a reporter pair, composed of the macrocyclic host cucurbit[7]uril (CB7) and the fluorescent dye acridine orange (AO), to detect the proteolytic degradation of peptides. The enzymatic activity of trypsin and leucine aminopeptidase (LAP) was investigated using H-LSRFSWGA-OH as a substrate. The substrate as well as the intermediary and final products (i.e., H-FSWGA-OH and phenylalanine) formed during its enzymatic hydrolysis differ in their binding affinity to the receptor CB7, which results in varying degrees of dye displacement and, therefore, different fluorescence intensities. CB7 showed a relatively weak binding constant of K ≈ 104 M–1 with the substrate, a relatively strong binding constant of K ≥ 106 M–1 with H-FSWGA-OH (which is a final product formed by trypsin digestion and the intermediary product formed during the enzymatic activity of LAP), and a moderate binding constant of K ≤ 105 M–1 with phenylalanine. Owing to this differential binding affinity of CB7 with the substrate and the corresponding products, the digestion of a peptide by trypsin was followed as a decrease in fluorescence signal, while the complete degradation of the peptide by LAP was monitored as a decrease and a subsequent increase in fluorescence signal. The kcat/ KM value for trypsin (2.0 × 107 min–1M–1) was derived from the change in fluorescence signal with time. Additionally, the complete degradation of the peptide by LAP was also followed by mass spectrometry. The use of a supramolecular sensing ensemble (macrocyclic host and dye) as a fluorescent reporter pair gives this method the flexibility to adapt for monitoring the stepwise degradation of different biologically relevant peptides by other proteases.
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Affiliation(s)
- Garima Ghale
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| | - Nikolai Kuhnert
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| | - Werner M. Nau
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
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Patsenker LD, Tatarets AL, Povrozin YA, Terpetschnig EA. Long-wavelength fluorescence lifetime labels. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s12566-011-0025-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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9
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Dsouza RN, Pischel U, Nau WM. Fluorescent dyes and their supramolecular host/guest complexes with macrocycles in aqueous solution. Chem Rev 2011; 111:7941-80. [PMID: 21981343 DOI: 10.1021/cr200213s] [Citation(s) in RCA: 797] [Impact Index Per Article: 61.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Roy N Dsouza
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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Abstract
The early detection of many human diseases is crucial if they are to be treated successfully. Therefore, the development of imaging techniques that can facilitate early detection of disease is of high importance. Changes in the levels of enzyme expression are known to occur in many diseases, making their accurate detection at low concentrations an area of considerable active research. Activatable fluorescent probes show immense promise in this area. If properly designed they should exhibit no signal until they interact with their target enzyme, reducing the level of background fluorescence and potentially endowing them with greater sensitivity. The mechanisms of fluorescence changes in activatable probes vary. This review aims to survey the field of activatable probes, focusing on their mechanisms of action as well as illustrating some of the in vitro and in vivo settings in which they have been employed.
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Affiliation(s)
- Christopher R Drake
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Box 0946, San Francisco, CA, 94107, USA
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Ghale G, Ramalingam V, Urbach AR, Nau WM. Determining protease substrate selectivity and inhibition by label-free supramolecular tandem enzyme assays. J Am Chem Soc 2011; 133:7528-35. [PMID: 21513303 DOI: 10.1021/ja2013467] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An analytical method has been developed for the continuous monitoring of protease activity on unlabeled peptides in real time by fluorescence spectroscopy. The assay is enabled by a reporter pair comprising the macrocycle cucurbit[7]uril (CB7) and the fluorescent dye acridine orange (AO). CB7 functions by selectively recognizing N-terminal phenylalanine residues as they are produced during the enzymatic cleavage of enkephalin-type peptides by the metalloendopeptidase thermolysin. The substrate peptides (e.g., Thr-Gly-Ala-Phe-Met-NH(2)) bind to CB7 with moderately high affinity (K ≈ 10(4) M(-1)), while their cleavage products (e.g., Phe-Met-NH(2)) bind very tightly (K > 10(6) M(-1)). AO signals the reaction upon its selective displacement from the macrocycle by the high affinity product of proteolysis. The resulting supramolecular tandem enzyme assay effectively measures the kinetics of thermolysin, including the accurate determination of sequence specificity (Ser and Gly instead of Ala), stereospecificity (d-Ala instead of l-Ala), endo- versus exopeptidase activity (indicated by differences in absolute fluorescence response), and sensitivity to terminal charges (-CONH(2) vs -COOH). The capability of the tandem assay to measure protease inhibition constants was demonstrated on phosphoramidon as a known inhibitor to afford an inhibition constant of (17.8 ± 0.4) nM. This robust and label-free approach to the study of protease activity and inhibition should be transferable to other endo- and exopeptidases that afford products with N-terminal aromatic amino acids.
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Affiliation(s)
- Garima Ghale
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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Tan HY, Cheong BHP, Neild A, Liew OW, Ng TW. Absorbance and fluorometric sensing with capillary wells microplates. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:124301. [PMID: 21198036 DOI: 10.1063/1.3509395] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Detection and readout from small volume assays in microplates are a challenge. The capillary wells microplate approach [Ng et al., Appl. Phys. Lett. 93, 174105 (2008)] offers strong advantages in small liquid volume management. An adapted design is described and shown here to be able to detect, in a nonimaging manner, fluorescence and absorbance assays minus the error often associated with meniscus forming at the air-liquid interface. The presence of bubbles in liquid samples residing in microplate wells can cause inaccuracies. Pipetting errors, if not adequately managed, can result in misleading data and wrong interpretations of assay results; particularly in the context of high throughput screening. We show that the adapted design is also able to detect for bubbles and pipetting errors during actual assay runs to ensure accuracy in screening.
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Affiliation(s)
- Han Yen Tan
- Laboratory for Optics, Acoustics, and Mechanics, Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
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Fernández D, Pallarès I, Vendrell J, Avilés FX. Progress in metallocarboxypeptidases and their small molecular weight inhibitors. Biochimie 2010; 92:1484-500. [PMID: 20466032 DOI: 10.1016/j.biochi.2010.05.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 05/04/2010] [Indexed: 01/11/2023]
Abstract
In what corresponds to a life span, metallocarboxypeptidases (MCPs) have jumped from being mere contaminants in animal pancreas powders (in depression year 1929) to be key players in cellular and molecular processes (in yet-another-depression years 2009-2010). MCPs are unique zinc-dependent enzymes that catalyze the breakdown of the amide bond at the C-terminus of peptide and protein substrates and participate in the recovery of dietary amino acids, tissue organogenesis, neurohormone and cytokine maturation and other important physiological processes. More than 26 genes code for MCPs in the human genome, many of them still waiting to be fully understood in terms of physiological function. A variety of MCPs have been linked to diseases in man: acute pancreatitis and pancreas cancer, type 2 diabetes, Alzheimer's Disease, various types of cancer, and fibrinolysis and inflammation. Many of these discoveries have been made possible thanks to recent advances, as exemplified by plasma carboxypeptidases N and B, known for fifty and twenty years, respectively, which have had their structures released only very recently. Plasma carboxypeptidase B is a biological target for therapy because of its involvement in the coagulation/fibrinolysis processes. Besides, the widespread use of carboxypeptidase A as a benchmark metalloprotease since the early days of Biochemistry has allowed the identification and design of an increasingly vast repertory of small molecular weight inhibitors. With these two examples we wish to emphasize that MCPs have become part of the drug discovery portfolio of pharmaceutical companies and academic research laboratories. This paper will review key developments in the discovery and design of MCP small molecular weight inhibitors, with an emphasis on the discovery of chemically diverse entities. Although encouraging advances have been achieved in the last few years, the specificity and oral bioavailability of the new chemotherapeutic agents seem to pose a challenge to medicinal chemists.
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Affiliation(s)
- Daniel Fernández
- Departament de Bioquímica i Biologia Molecular, Facultat de Biociències and Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
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Resch-Genger U, Grabolle M, Nitschke R, Nann T. Nanocrystals and Nanoparticles Versus Molecular Fluorescent Labels as Reporters for Bioanalysis and the Life Sciences: A Critical Comparison. ADVANCED FLUORESCENCE REPORTERS IN CHEMISTRY AND BIOLOGY II 2010. [DOI: 10.1007/978-3-642-04701-5_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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15
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Brolich MA, Wang L, O'Neill MA. Folding kinetics of recognition loop peptides from a photolyase and cryptochrome-DASH. Biochem Biophys Res Commun 2009; 391:874-8. [PMID: 19945437 DOI: 10.1016/j.bbrc.2009.11.155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2009] [Accepted: 11/21/2009] [Indexed: 11/16/2022]
Abstract
Cryptochromes (CRY) and photolyases (PL) use a common flavin adenine dinucleotide cofactor and homologous protein scaffold to accomplish numerous, seemingly dissimilar functions. PL repairs UV-damaged DNA in a mechanism requiring light and DNA base flipping. CRY cannot repair DNA, and instead function in core biological processes including plant photomorphogenesis, circadian rhythm, and magnetoreception. One subclass, CRY-DASH, does catalyze repair of single-stranded DNA; compromised base flipping may deactivate its tight binding to duplex DNA substrates. We recently demonstrated that the a "recognition loop" involved in DNA binding by both PL and CRY-DASH is among the most flexible regions in the two proteins, and exhibits especially heightened dynamics in CRY-DASH. Here, we establish that these distinct dynamics are encoded by the loop sequences: we quantify the flexibility of the isolated loop peptides through the kinetics and activation parameters for their folding. Mirroring the dynamics within the proteins, the CRY-DASH recognition loop peptide folds 2.5-fold faster than its counterpart in PL, predominantly due to a lower enthalpy of activation. We propose that these distinct dynamics are functionally significant in DNA recognition. Binding duplex DNA in the catalytically-active base-flipped conformation imposes significant order on the recognition loop, and a corresponding entropic penalty. This may be surmounted by the more preorganized PL recognition loop, but may impose too large a barrier for the more dynamic loop in CRY-DASH. These results suggest that evolution of protein dynamics, through local sequence tuning in the recognition loop, may be an important mechanism for functional diversification in PL and CRY.
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Affiliation(s)
- Matthew A Brolich
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
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16
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Unnatural benz-X-azolyl asparagine derivatives as novel fluorescent amino acids: synthesis and photophysical characterization. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.08.086] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Nau WM, Ghale G, Hennig A, Bakirci H, Bailey DM. Substrate-Selective Supramolecular Tandem Assays: Monitoring Enzyme Inhibition of Arginase and Diamine Oxidase by Fluorescent Dye Displacement from Calixarene and Cucurbituril Macrocycles. J Am Chem Soc 2009; 131:11558-70. [DOI: 10.1021/ja904165c] [Citation(s) in RCA: 184] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Werner M. Nau
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
| | - Garima Ghale
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
| | - Andreas Hennig
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
| | - Hüseyin Bakirci
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
| | - David M. Bailey
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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18
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Sahoo H, Hennig A, Florea M, Roth D, Enderle T, Nau WM. Single-label kinase and phosphatase assays for tyrosine phosphorylation using nanosecond time-resolved fluorescence detection. J Am Chem Soc 2007; 129:15927-34. [PMID: 18044894 DOI: 10.1021/ja074975w] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The collision-induced fluorescence quenching of a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo) by hydrogen atom abstraction from the tyrosine residue in peptide substrates was introduced as a single-labeling strategy to assay the activity of tyrosine kinases and phosphatases. The assays were tested for 12 different combinations of Dbo-labeled substrates and with the enzymes p60c-Src Src kinase, EGFR kinase, YOP protein tyrosine phosphatase, as well as acid and alkaline phosphatases, thereby demonstrating a broad application potential. The steady-state fluorescence changed by a factor of up to 7 in the course of the enzymatic reaction, which allowed for a sufficient sensitivity of continuous monitoring in steady-state experiments. The fluorescence lifetimes (and intensities) were found to be rather constant for the phosphotyrosine peptides (ca. 300 ns in aerated water), while those of the unphosphorylated peptides were as short as 40 ns (at pH 7) and 7 ns (at pH 13) as a result of intramolecular quenching. Owing to the exceptionally long fluorescence lifetime of Dbo, the assays were alternatively performed by using nanosecond time-resolved fluorescence (Nano-TRF) detection, which leads to an improved discrimination of background fluorescence and an increased sensitivity. The potential for inhibitor screening was demonstrated through the inhibition of acid and alkaline phosphatases by molybdate.
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Affiliation(s)
- Harekrushna Sahoo
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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Nau WM, Hennig A, Koner AL. Squeezing Fluorescent Dyes into Nanoscale Containers—The Supramolecular Approach to Radiative Decay Engineering. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/4243_2007_007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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20
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Lebakken CS, Vogel KW. A fluorescence lifetime based binding assay to characterize kinase inhibitors. ACTA ACUST UNITED AC 2007; 12:828-41. [PMID: 17644772 DOI: 10.1177/1087057107304480] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The authors present a fluorescence lifetime-based kinase binding assay that identifies and characterizes compounds that bind to the adenosine triphosphate (ATP)-binding pocket of a range of tyrosine and serine/threonine kinases. The assay is based on displacement of an Alexa Fluor 647 conjugate of staurosporine from the ATP-binding site of a kinase, which is detected by a change in the fluorescence lifetime of the probe between the free (displaced) and kinase-bound states. The authors screened 257 kinases for specific binding and displacement of the Alexa Fluor 647-staurosporine probe and found that approximately half of the kinases tested could potentially be assayed with this method. They present inhibitor binding data against 4 selected serine/threonine kinases and 4 selected tyrosine kinases, using 6 commonly used kinase inhibitors. Two of these kinases were chosen for further studies, in which inhibitor binding data were compared to inhibition of kinase activity using 2 separate activity assay formats. Rank-order potencies of compounds were similar, but not identical, between the binding and activity assays. It was postulated that these differences could be caused by the fact that the assays are measuring distinct phenomena, namely, activity versus binding, and in a purified recombinant kinase preparation, there can exist a mixture of active and nonactivated kinases. To explore this possibility, the authors compared binding affinity for the probe using 2 kinases in their respective nonactivated and activated (phosphorylated) forms and found a kinase-dependent difference between the 2 forms. This assay format therefore represents a simple method for the identification and characterization of small-molecule kinase inhibitors that may be useful in screening a wide range of kinases and may be useful in identifying small molecules that bind to kinases in their active or nonactivated states.
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