1
|
Preston-Herrera C, Jackson AS, Bachmann BO, Froese JT. Development and application of a high throughput assay system for the detection of Rieske dioxygenase activity. Org Biomol Chem 2021; 19:775-784. [PMID: 33439179 DOI: 10.1039/d0ob02412k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Herein we report the development of a new periodate-based reactive assay system for the fluorescent detection of the cis-diol metabolites produced by Rieske dioxygenases. This sensitive and diastereoselective assay system successfully evaluates the substrate scope of Rieske dioxygenases and determines the relative activity of a rationally designed Rieske dioxygenase variant library. The high throughput capacity of the assay system enables rapid and efficient substrate scope investigations and screening of large dioxygenase variant libraries.
Collapse
Affiliation(s)
| | - Aaron S Jackson
- Department of Chemistry, Ball State University, 2000 W Riverside Ave, Muncie, IN 47306, USA.
| | - Brian O Bachmann
- Department of Chemistry, Vanderbilt University, 7330 Stevenson Center, Station B 351822, Nashville, TN 37235, USA
| | - Jordan T Froese
- Department of Chemistry, Ball State University, 2000 W Riverside Ave, Muncie, IN 47306, USA.
| |
Collapse
|
2
|
Ahmed IA, Rodgers JM, Eng C, Troxler T, Gai F. PET and FRET utility of an amino acid pair: tryptophan and 4-cyanotryptophan. Phys Chem Chem Phys 2019; 21:12843-12849. [PMID: 31179453 PMCID: PMC6587589 DOI: 10.1039/c9cp02126d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Methods based on fluorescence resonance energy transfer (FRET) and photo-induced electron transfer (PET) are widely used in the biological sciences, employing mostly dye-based FRET and PET pairs. While very useful and important, dye-based reporters are not always applicable without concern, for example, in cases where the fluorophore size needs to be minimized. Therefore, development and characterization of smaller, ideally amino acid-based PET and FRET pairs will expand the biological spectroscopy toolbox to enable new applications. Herein, we show that, depending on the excitation wavelength, tryptophan and 4-cyanotrptophan can interact with each other via the mechanism of either energy or electron transfer, hence constituting a dual FRET and PET pair. The biological utility of this amino acid pair is further demonstrated by applying it to study the end-to-end collision rate of a short peptide, the mode of interaction between a ligand and BSA, and the activity of a protease.
Collapse
Affiliation(s)
- Ismail A. Ahmed
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jeffrey M. Rodgers
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Christina Eng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Thomas Troxler
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Feng Gai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
3
|
Kjaer C, Lissau H, Gravesen Salinas NK, Østergaard Madsen A, Stockett MH, Storm FE, Holm Hansen T, Andersen JU, Laursen BW, Mikkelsen KV, Brøndsted Nielsen M, Brøndsted Nielsen S. Luminescence Spectroscopy of Rhodamine Homodimer Dications in Vacuo
Reveals Strong Dye-Dye Interactions. Chemphyschem 2019; 20:533-537. [DOI: 10.1002/cphc.201800933] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/04/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Christina Kjaer
- Department of Physics and Astronomy; Aarhus University; Denmark
| | | | | | | | | | - Freja E. Storm
- Department of Chemistry; University of Copenhagen; Denmark
| | | | | | - Bo W. Laursen
- Department of Chemistry; University of Copenhagen; Denmark
| | | | | | | |
Collapse
|
4
|
Huang J, Su X, Li Z. Enzyme-Free and Amplified Fluorescence DNA Detection Using Bimolecular Beacons. Anal Chem 2012; 84:5939-43. [DOI: 10.1021/ac3004727] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Jiahao Huang
- Department of Mechanical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong
| | - Xuefen Su
- School of Public Health and
Primary Care, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories,
Hong Kong
| | - Zhigang Li
- Department of Mechanical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong
| |
Collapse
|
5
|
Mikhalyov I, Samsonov A. Lipid raft detecting in membranes of live erythrocytes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:1930-9. [DOI: 10.1016/j.bbamem.2011.04.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 03/15/2011] [Accepted: 04/04/2011] [Indexed: 11/27/2022]
|
6
|
Benniston AC, Copley G, Harriman A, Howgego D, Harrington RW, Clegg W. Cofacial Boron Dipyrromethene (Bodipy) Dimers: Synthesis, Charge Delocalization, and Exciton Coupling. J Org Chem 2010; 75:2018-27. [DOI: 10.1021/jo1000803] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
7
|
EDMAN PETER, HÅKANSSON PÄR, WESTLUND PEROLOF, JOHANSSON LENNARTBÅ. Extended Förster theory of donor-donor energy migration in bifluorophoric macromolecules. Part I. A new approach to quantitative analyses of the time-resolved fluorescence anisotropy. Mol Phys 2009. [DOI: 10.1080/00268970009483358] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- PETER EDMAN
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
| | - PÄR HÅKANSSON
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
| | - PER-OLOF WESTLUND
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
| | - LENNART B.-Å. JOHANSSON
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
| |
Collapse
|
8
|
Harriman A, Mallon L, Goeb S, Ulrich G, Ziessel R. Electronic Energy Transfer to the S2Level of the Acceptor in Functionalised Boron Dipyrromethene Dyes. Chemistry 2009; 15:4553-64. [DOI: 10.1002/chem.200802477] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
9
|
Harriman A, Mallon L, Ziessel R. Energy Flow in a Purpose-Built Cascade Molecule Bearing Three Distinct Chromophores Attached to the Terminal Acceptor. Chemistry 2008; 14:11461-73. [DOI: 10.1002/chem.200801384] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
10
|
Glasscock JM, Zhu Y, Chowdhury P, Tang J, Gai F. Using an amino acid fluorescence resonance energy transfer pair to probe protein unfolding: application to the villin headpiece subdomain and the LysM domain. Biochemistry 2008; 47:11070-6. [PMID: 18816063 DOI: 10.1021/bi8012406] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Previously, we have shown that p-cyanophenylalanine (Phe CN) and tryptophan (Trp) constitute an efficient fluorescence resonance energy transfer (FRET) pair that has several advantages over commonly used dye pairs. Here, we aim to examine the general applicability of this FRET pair in protein folding-unfolding studies by applying it to the urea-induced unfolding transitions of two small proteins, the villin headpiece subdomain (HP35) and the lysin motif (LysM) domain. Depending on whether Phe CN is exposed to solvent, we are able to extract either qualitative information about the folding pathway, as demonstrated by HP35, which has been suggested to unfold in a stepwise manner, or quantitative thermodynamic and structural information, as demonstrated by LysM, which has been shown to be an ideal two-state folder. Our results show that the unfolding transition of HP35 reported by FRET occurs at a denaturant concentration lower than that measured by circular dichroism (CD) and that the loop linking helix 2 and helix 3 remains compact in the denatured state, which are consistent with the notion that HP35 unfolds in discrete steps and that its unfolded state contains residual structures. On the other hand, our FRET results on the LysM domain allow us to develop a model for extracting structural and thermodynamic parameters about its unfolding, and we find that our results are in agreement with those obtained by other methods. Given the fact that Phe CN is a non-natural amino acid and, thus, amenable to incorporation into peptides and proteins via existing peptide synthesis and protein expression methods, we believe that the FRET method demonstrated here is widely applicable to protein conformational studies, especially to the study of relatively small proteins.
Collapse
Affiliation(s)
- Julie M Glasscock
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | |
Collapse
|
11
|
Choi JH, Oh KI, Lee H, Lee C, Cho M. Nitrile and thiocyanate IR probes: Quantum chemistry calculation studies and multivariate least-square fitting analysis. J Chem Phys 2008; 128:134506. [DOI: 10.1063/1.2844787] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
|
12
|
Kalinin S, Felekyan S, Antonik M, Seidel CAM. Probability Distribution Analysis of Single-Molecule Fluorescence Anisotropy and Resonance Energy Transfer. J Phys Chem B 2007; 111:10253-62. [PMID: 17676789 DOI: 10.1021/jp072293p] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Analysis of anisotropy in single-molecule fluorescence experiments using the probability distribution analysis (PDA) method is presented. The theory of anisotropy-PDA is an extension of the PDA theory recently developed for the analysis of Förster resonance energy transfer (FRET) signals [Antonik, M.; et al. J. Phys. Chem. B 2006, 110, 6970]. The PDA method predicts the shape of anisotropy histograms for any given expected ensemble anisotropy, signal intensity distribution, and background. Further improvements of the PDA theory allow one to work with very low photon numbers, i.e., starting from the level of background signal. Analysis of experimental and simulated data shows that PDA has the major advantage to unambiguously distinguish between shot noise broadening and broadening caused by heterogeneities in the sample. Fitting of experimental histograms yields anisotropy values of individual species, which can be directly compared with those measured in ensemble experiments. Excellent agreement between the ensemble data and the results of PDA demonstrates a good absolute accuracy of the PDA method. The precision in determination of mean values depends mainly on the total number of photons, whereas the ability of PDA to detect the presence of heterogeneities strongly depends on the time window length. In its present form PDA can be also applied to computed fluorescence parameters such as FRET efficiency and scatter-corrected fluorescence anisotropy. Extension of the PDA theory to low photon numbers makes it possible to apply PDA to dynamic systems, for which high time resolution is required. In this way PDA is developed as a sensitive tool to detect biomolecular heterogeneities in space and time.
Collapse
Affiliation(s)
- Stanislav Kalinin
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine Universität, Universitätsstrasse 1, Geb 26.32, 40225 Düsseldorf, Germany.
| | | | | | | |
Collapse
|
13
|
Benesch J, Hungerford G, Suhling K, Tregidgo C, Mano JF, Reis RL. Fluorescence probe techniques to monitor protein adsorption-induced conformation changes on biodegradable polymers. J Colloid Interface Sci 2007; 312:193-200. [PMID: 17467001 DOI: 10.1016/j.jcis.2007.03.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Revised: 03/09/2007] [Accepted: 03/10/2007] [Indexed: 11/28/2022]
Abstract
The study of protein adsorption and any associated conformational changes on interaction with biomaterials is of great importance in the area of implants and tissue constructs. This study aimed to evaluate some fluorescent techniques to probe protein conformation on a selection of biodegradable polymers currently under investigation for biomedical applications. Because of the fluorescence emanating from the polymers, the use of monitoring intrinsic protein fluorescence was precluded. A highly solvatochromic fluorescent dye, Nile red, and a well-known protein label, fluorescein isothiocyanate, were employed to study the adsorption of serum albumin to polycaprolactone and to some extent also to two starch-containing polymer blends (SPCL and SEVA-C). A variety of fluorescence techniques, steady state, time resolved, and imaging were employed. Nile red was found to leach from the protein, while fluorescein isothiocyanate proved useful in elucidating a conformational change in the protein and the observation of protein aggregates adsorbed to the polymer surface. These effects were seen by making use of the phenomenon of energy migration between the fluorescent tags to monitor interprobe distance and the use of fluorescence lifetime imaging to ascertain the surface packing of the protein on polymer.
Collapse
Affiliation(s)
- Johan Benesch
- 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, 4710-057 Braga, Portugal.
| | | | | | | | | | | |
Collapse
|
14
|
Isaksson M, Hägglöf P, Håkansson P, Ny T, Johansson LBA. Extended Förster theory for determining intraprotein distances: 2. An accurate analysis of fluorescence depolarisation experiments. Phys Chem Chem Phys 2007; 9:3914-22. [PMID: 17637983 DOI: 10.1039/b701591g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The extended Förster theory (EFT) is for the first time applied to the quantitative determination of the intramolecular distances in proteins. It is shown how the EFT (J. Chem. Phys., 1996, 105, 10896) can be adapted to the analyses of fluorescence depolarisation experiments based on the time-correlated single photon counting technique (TCSPC). The protein system studied was the latent form of plasminogen activator inhibitor type I (PAI-1), which was mutated and labelled by the thiol reactive BODIPY(R) derivative {N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl iodoacetamide}. The energy migration occurs within pairs of photophysically identical donor groups that undergo reorientational motions on the timescales of energy migration and fluorescence relaxation. Unlike all models currently used for analysing fluorescence TCSPC data, the EFT explicitly accounts for the time-dependent reorientations that influence the rate of electronic energy transfer/migration in a complex manner. The complexity is related to the "kappa(2) problem", which has been discussed for years. The EFT brings the analyses of DDEM data to the same level of molecular description as in ESR and NMR spectroscopy, i.e. it yields microscopic information about the reorientation correlation times, the order parameters, as well as inter-chromophoric distances.
Collapse
Affiliation(s)
- Mikael Isaksson
- Department of Chemistry, Biophysical Chemistry, University of Umeå, S-901 87 Umeå, Sweden
| | | | | | | | | |
Collapse
|
15
|
Hungerford G, Benesch J, Mano JF, Reis RL. Effect of the labelling ratio on the photophysics of fluorescein isothiocyanate (FITC) conjugated to bovine serum albumin. Photochem Photobiol Sci 2006; 6:152-8. [PMID: 17277838 DOI: 10.1039/b612870j] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The non-linearity of the fluorescence emission on increasing the probe to protein ratio has long been regarded as problematic and has lead to the development of dyes to overcome this effect. One of the causes of this non-linear response can be ascribed to the overlap of the label's own absorption and emission spectra. At higher labelling ratios, this affords the possibility of a reasonably efficient energy migration pathway, thus reducing the observed quantum yield of the dye. In this work we study the photophysics of fluorescein isothiocyanate (FITC) when conjugated to bovine serum albumin (BSA) at different labelling ratios (in the range FITC : BSA 1 : 17-15 : 1) using both steady state and time-resolved fluorescence techniques where on going from under labelled to over labelled samples a decrease in the initial (and steady state) anisotropy is observed, accompanied by an increase in the complexity of the decay kinetics and a decrease in the average lifetime. The band structure, elucidated by synchronous scan fluorescence spectroscopy, is also found to change on increased labelling. These results can be applied to the study of protein conformation and were confirmed by the analysis of denaturing BSA using urea.
Collapse
Affiliation(s)
- Graham Hungerford
- Departamento de Fisica, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
| | | | | | | |
Collapse
|
16
|
Prieto JB, Arbeloa T, Liras M, Martínez VM, Arbeloa FL. Concerning the color change of pyrromethene 650 dye in electron-donor solvents. J Photochem Photobiol A Chem 2006. [DOI: 10.1016/j.jphotochem.2006.04.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
17
|
Tucker MJ, Oyola R, Gai F. A novel fluorescent probe for protein binding and folding studies:p-cyano-phenylalanine. Biopolymers 2006; 83:571-6. [PMID: 16917881 DOI: 10.1002/bip.20587] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recently, it is has been shown that the C=N stretching vibration of a non-natural amino acid, p-cyano-phenylalanine (PheCN), could be used as an infrared reporter of local environment. Here, we further showed that the fluorescence emission of PheCN is also sensitive to solvent and, therefore, could be used as a novel optical probe for protein binding and folding studies. Moreover, we found that the fluorescence quantum yield of PheCN is nearly five times larger than that of phenylalanine and, more importantly, can be selectively excited even when other aromatic amino acids are present, thus making it a more versatile fluorophore. To test the feasibility of using PheCN as a practical fluorescent probe, we studied the binding of calmodulin (CaM) to a peptide derived from the CaM-binding domain of skeletal muscle myosin light chain kinase (MLCK). The peptide (MLCK3CN) contains a single PheCN residue and has been shown to bind to CaM with high affinity. As expected, addition of CaM into a MLCK3CN solution resulted in quenching of the PheCN fluorescence. A series of stochiometric titrations further allowed us to determine the binding affinity (Kd) of this peptide to CaM. Taken together, these results indicated that the PheCN fluorescence is sensitive to environment and could be applicable to a wide variety of biological problems.
Collapse
Affiliation(s)
- Matthew J Tucker
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | |
Collapse
|
18
|
Bene L, Szöllosi J, Szentesi G, Damjanovich L, Gáspár R, Waldmann TA, Damjanovich S. Detection of receptor trimers on the cell surface by flow cytometric fluorescence energy homotransfer measurements. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1744:176-98. [PMID: 15950751 DOI: 10.1016/j.bbamcr.2005.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 02/08/2005] [Accepted: 02/09/2005] [Indexed: 11/26/2022]
Abstract
Fluorescence energy homotransfer offers a powerful tool for the investigation of the state of oligomerization of cell surface receptors on a cell-by-cell basis by measuring the polarized components of fluorescence intensity of cells labeled with fluorescently stained antibodies. Here we describe homotransfer-based methods for the flow cytometric detection and analysis of hetero- and homo-associations of cell surface receptors. Homotransfer efficiencies for two- and three-body energy transfer interactions are defined and their frequency distribution curves are computed from the fluorescence anisotropy distributions of multiple-labeled cells. The fractions of receptors involved in homo-clustering is calculated based on the dependence of the fluorescence anisotropy on the surface concentration of the fluorescently stained antibodies. A homotransfer analysis of the homo- and hetero-clustering of the MHCI and MHCII glycoproteins, the cytokine receptor IL-2Ralpha, transferrin receptor and the receptor-type tyrosine phosphatase CD45 on JY B and Kit-225-K6 T cells is presented. We investigated how various factors such as the type of dye, rotational mobility of the dye and dye-targeting antibody, as well as the wavelength of the exciting light affect the homotransfer. We show that the homotransfer technique combined with the high statistical resolution of flow cytometry is an effective tool for detecting different oligomeric states of receptors by using fluorophores having restricted rotational mobility on the time scale of fluorescence.
Collapse
Affiliation(s)
- László Bene
- Department of Biophysics and Cell Biology, Medical and Health Science Center, Research Center for Molecular Medicine, University of Debrecen, Hungary.
| | | | | | | | | | | | | |
Collapse
|
19
|
Marmé N, Habl G, Knemeyer JP. Aggregation behavior of the red-absorbing oxazine derivative MR 121: A new method for determination of pure dimer spectra. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
20
|
Tucker MJ, Oyola R, Gai F. Conformational Distribution of a 14-Residue Peptide in Solution: A Fluorescence Resonance Energy Transfer Study. J Phys Chem B 2005; 109:4788-95. [PMID: 16851563 DOI: 10.1021/jp044347q] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We demonstrate here that a nitrile-derivatized phenylalanine residue, p-cyanophenylalanine (Phe(CN)), and tryptophan (Trp) constitute a novel donor-acceptor pair for fluorescence resonance energy transfer (FRET). The Förster distance of this FRET pair was determined to be approximately 16 A and hence is well suited for determining relatively short separation distances. To validate the applicability of this FRET pair in conformational studies, we studied the conformational heterogeneity of a 14-residue amphipathic peptide, Mastoparan X (MPx peptide), in water and 7 M urea solution as well as at different temperatures. Specifically, seven nitrile-derivatized mutants of the MPx peptide, each containing a Phe(CN) residue that replaces different positions along the peptide sequence (i.e., from position 5 to 11) and serves as a resonance energy donor to the native Trp residue at position 3, were studied spectroscopically. The FRET efficiencies obtained from these peptides allowed us to gain a global picture regarding the conformational distribution of the MPx peptide in different environments. Our results suggest that the MPx molecules exist in water as an ensemble of rather compact conformations, with a radius of gyration of approximately 4.2 A, whereas in 7 M urea the radius of gyration increases to approximately 6.5 A, indicating that the peptide conformations become more extended under this condition. However, we found that temperature had only a negligible effect on the size of the MPx peptide, underlining the difference between the thermally and chemically denatured states of polypeptides. The application of the Gaussian chain or the wormlike chain model allowed us to further obtain the probability distribution function of the separation distance between any two residues along the peptide sequence. We found that the effective bond length of the MPx peptide, obtained by using the Gaussian chain model, is 2.78 A in water and 4.28 A in 7 M urea.
Collapse
Affiliation(s)
- Matthew J Tucker
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | | | |
Collapse
|
21
|
Kalinin S, Johansson LBA. Utility and considerations of donor-donor energy migration as a fluorescence method for exploring protein structure-function. J Fluoresc 2005; 14:681-91. [PMID: 15649020 DOI: 10.1023/b:jofl.0000047218.51768.59] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This review aims at surveying the use of electronic energy transport between chemically identical fluorophores (i.e. donors) in studies of various protein systems. Applications of intra- and interprotein energy migration are presented that make use of polarised steady-state and time-resolved fluorescence spectroscopic techniques. The donor-donor energy migration (DDEM) and the partial donor-donor energy migration (PDDEM) models for calculating distances between donor groups are exposed together with the most recent development of an extended Forster theory (EFT). Synthetic fluorescence depolarisation data that mimic time-correlated single photon counting experiments were generated using the EFT, and then further re-analysed by the different models. The results obtained were compared with the known parameters used to generate EFT data. Aspects on how to adopt the EFT in the analyses of time-correlated single photon counting experiments are also presented, as well as future aspects on using energy migration for examining protein structure.
Collapse
Affiliation(s)
- Stanislav Kalinin
- Department of Chemistry, Biophysical Chemistry, University of Umeå, S-901 87 Umeå, Sweden
| | | |
Collapse
|
22
|
Dong SY, Ma HM, Duan XJ, Chen XQ, Li J. Detection of Local Polarity of α-Lactalbumin by N-Terminal Specific Labeling with a New Tailor-Made Fluorescent Probe. J Proteome Res 2005; 4:161-6. [PMID: 15707371 DOI: 10.1021/pr049814v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To detect the local polarity such as the N-terminal domain of a protein molecule, 3-(4-chloro-6-hydrazino-1,3,5-triazinylamino)-7-(dimethylamino)-2-methylphenazine has been designed and synthesized as a polarity-sensitive fluorescent probe by using an s-triazine ring as a backbone, neutral red and hydrazine as a polarity-sensitive fluorophore, and a labeling group, respectively. The fluorescence properties of the probe have been characterized. The probe has the following features: (1) stable in various solvents; (2) the long-wavelength emission of >550 nm that can avoid the interferences of the background fluorescence shorter than 500 nm from common biomacromolecules; and (3) the maximum emission wavelength (lambda(em)) sensitive to solvent polarity only but not to pH and temperature. The hydrazino group in such a probe reacts readily with an active carbonyl produced by transamination of a protein molecule, leading to N-terminal specific attachment of the fluorophore and thereby allowing the monitoring of local polarity. With this probe, the polarity of the N-terminal domain in both native and heat-denatured alpha-lactalbumin has been first determined, which corresponds to that with a dielectric constant of about 16, and the hydrophobic core near the N-terminus is found to be conservative for heating. The present strategy may provide a general method to study the local environmental changes of a protein molecule under different denaturation conditions.
Collapse
Affiliation(s)
- Su-Ying Dong
- Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
| | | | | | | | | |
Collapse
|
23
|
Håkansson P, Isaksson M, Westlund PO, Johansson LBÅ. Extended Förster Theory for Determining Intraprotein Distances. 1. The κ2-Dynamics and Fluorophore Reorientation. J Phys Chem B 2004. [DOI: 10.1021/jp040423d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pär Håkansson
- Department of Chemistry; Biophysical Chemistry, University of Umeå, S-901 87 Umeå, Sweden
| | - Mikael Isaksson
- Department of Chemistry; Biophysical Chemistry, University of Umeå, S-901 87 Umeå, Sweden
| | - Per-Olof Westlund
- Department of Chemistry; Biophysical Chemistry, University of Umeå, S-901 87 Umeå, Sweden
| | | |
Collapse
|
24
|
Lakowicz JR, Geddes CD, Gryczynski I, Malicka J, Gryczynski Z, Aslan K, Lukomska J, Matveeva E, Zhang J, Badugu R, Huang J. Advances in surface-enhanced fluorescence. J Fluoresc 2004; 14:425-41. [PMID: 15617385 PMCID: PMC2763917 DOI: 10.1023/b:jofl.0000031824.48401.5c] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report recent achievements in metal-enhanced fluorescence from our laboratory. Several fluorophore systems have been studied on metal particle-coated surfaces and in colloid suspensions. In particular, we describe a distance dependent enhancement on silver island films (SIFs), release of self-quenching of fluorescence near silver particles, and the applications of fluorescence enhancement near metalized surfaces to bioassays. We discuss a number of methods for various shaped silver particle deposition on surfaces.
Collapse
Affiliation(s)
- Joseph R. Lakowicz
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Chris D. Geddes
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Ignacy Gryczynski
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joanna Malicka
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Zygmunt Gryczynski
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Kadir Aslan
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joanna Lukomska
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Evgenia Matveeva
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Jian Zhang
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Ramachandram Badugu
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Jun Huang
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland, 725 West Lombard Street, Baltimore, Maryland 21201
| |
Collapse
|
25
|
Kalinin S, Johansson LBÅ. Energy Migration and Transfer Rates Are Invariant to Modeling the Fluorescence Relaxation by Discrete and Continuous Distributions of Lifetimes. J Phys Chem B 2004. [DOI: 10.1021/jp031096x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
26
|
Isaksson M, Kalinin S, Lobov S, Wang S, Ny T, Johansson LBÅ. Partial donor–donor energy migration (PDDEM): A novel fluorescence method for internal protein distance measurements. Phys Chem Chem Phys 2004. [DOI: 10.1039/b403264k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
27
|
Hägglöf P, Bergström F, Wilczynska M, Johansson LBA, Ny T. The Reactive-center Loop of Active PAI-1 is Folded Close to the Protein Core and can be Partially Inserted. J Mol Biol 2004; 335:823-32. [PMID: 14687577 DOI: 10.1016/j.jmb.2003.11.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plasminogen activator inhibitor 1 (PAI-1) is the main inhibitor of plasminogen activators and plays an important role in many pathophysiological processes. Like other members of the serpin family, PAI-1 has a reactive center consisting of a mobile loop (RCL) with P1 and P1' residues acting as a "bait" for cognate protease. In contrast to the other serpins, PAI-1 loses activity by spontaneous conversion to an inactive latent form. This involves full insertion of the RCL into beta-sheet A. To search for molecular determinants that could be responsible for conversion of PAI-1 to the latent form, we studied the conformation of the RCL in active PAI-1 in solution. Intramolecular distance measurements by donor-donor energy migration and probe quenching methods reveal that the RCL is located much closer to the core of PAI-1 than has been suggested by the recently resolved X-ray structures of stable PAI-1 mutants. Disulfide bonds can be formed in double-cysteine mutants with substitutions at positions P11 or P13 of the RCL and neighboring residues in beta-sheet A. This suggests that the RCL may be preinserted up to residue P13 in active PAI-1, and possibly even to residue P11. We propose that the close proximity of the RCL to the protein core, and the ability of the loop to preinsert into beta-sheet A is a possible reason for PAI-1 being able to convert spontaneously to its latent form.
Collapse
Affiliation(s)
- Peter Hägglöf
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
| | | | | | | | | |
Collapse
|
28
|
Lakowicz JR, Malicka J, D'Auria S, Gryczynski I. Release of the self-quenching of fluorescence near silver metallic surfaces. Anal Biochem 2003; 320:13-20. [PMID: 12895465 PMCID: PMC2753826 DOI: 10.1016/s0003-2697(03)00351-8] [Citation(s) in RCA: 173] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Fluorescein is one of the most widely used fluorescent probes in microscopy, biotechnology, and clinical assays. One difficulty with fluorescein is its self-quenching, which results in decreased intensities with increasing labeling density. In this study we examined human serum albumin (HSA), which contained one to nine covalently linked fluorescein molecules per molecule of HSA. The occurrence of homo resonance energy transfer for labeling ratios greater than 1 were confirmed by decreases in the relative quantum yields, anisotropies, and lifetimes. We found that most of the self-quenching can be partially eliminated by proximity of the labeled protein to metallic silver particles. These results suggest the use of heavily labeled proteins and metallic colloids to obtain ultrabright reagents for use in immunoassays, imaging, and other applications.
Collapse
Affiliation(s)
- Joseph R Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA.
| | | | | | | |
Collapse
|
29
|
Otto H, Lamparter T, Borucki B, Hughes J, Heyn MP. Dimerization and inter-chromophore distance of Cph1 phytochrome from Synechocystis, as monitored by fluorescence homo and hetero energy transfer. Biochemistry 2003; 42:5885-95. [PMID: 12741847 DOI: 10.1021/bi026946y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the dimerization of phytochrome Cph1 from the cyanobacterium Synechocystis by fluorescence resonance energy transfer (FRET). As donor we used the chromophore analogue phycoerythrobilin (PEB) and as acceptor either the natural chromophore phycocyanobilin (PCB; hetero transfer) or PEB (homo transfer). Both chromophores bind in a 1:1 stoichiometry to apo-monomers expressed in Escherichia coli. Energy transfer was characterized by time-resolved fluorescence intensity and anisotropy decay after excitation of PEB by picosecond pulses from a tunable Ti-sapphire laser system. ApoCph1 was first assembled with PEB at a low stoichiometry of 0.1. The remaining sites were then sequentially titrated with PCB. In the course of this titration, the mean lifetime of PEB decreased from 3.33 to 1.25 ns in the P(r) form of Cph1, whereas the anisotropy decay was unaffected. In the P(fr)/P(r) photoequilibrium (about 65% P(fr)), the mean lifetime decreased significantly less, to 1.67 ns. These observations provide strong support for inter-chromophore hetero energy transfer in mixed PEB/PCB dimers. The reduced energy transfer in P(fr) may be due to a structural difference but is at least in part due to the difference in spectral overlap, which was 4.1 x 10(-13) and 1.6 x 10(-13) cm(3) M(-1) in P(r) and P(fr), respectively. From the changes in the mean lifetime, rates of hetero energy transfer of 0.68 and 0.37 ns(-1) were calculated for the P(r) form and the P(fr)/P(r) photoequilibrium, respectively. Sequential titration of apo Cph1 with PEB alone to full occupancy did not affect the intensity decay but led to a substantial increase in depolarization. This is the experimental signature of homo energy transfer. Values for the rate of energy transfer k(HT) (0.47 ns(-1)) and the angle 2theta between the transition dipole moment directions (2theta = 45 +/- 5 degrees) were determined from an analysis of the concentration dependence of the anisotropy at five different PEB/Cph1 stoichiometries. The independently determined rates of hetero and homo energy transfer are thus of comparable magnitude and consistent with the energy transfer interpretation. Using these results and exploiting the 2-fold symmetry of the dimer, the chromophore-chromophore distance R(DA) was calculated and found to be in the range 49 A < R(DA) < 63 A. Further evidence for energy transfer in Cph1 dimers was obtained from dilution experiments with PEB/PEB dimers: the lifetime was unchanged, but the anisotropy increased as the dimers dissociated with increasing dilution. These experiments allowed a rough estimate of 5 +/- 3 microM for the dimer dissociation constant. With the deletion mutant Cph1Delta2 that lacks the carboxy terminal histidine kinase domain less energy transfer was observed suggesting that in this mutant dimerization is much weaker. The carboxy terminal domain of Cph1 that is involved in intersubunit trans-phosphorylation and signal transduction thus plays a dominant role in the dimerization. The FRET method provides a sensitive assay to monitor the association of Cph1 monomers.
Collapse
Affiliation(s)
- Harald Otto
- Biophysics Group, Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | | | | | | | | |
Collapse
|
30
|
Alexiev U, Rimke I, Pöhlmann T. Elucidation of the nature of the conformational changes of the EF-interhelical loop in bacteriorhodopsin and of the helix VIII on the cytoplasmic surface of bovine rhodopsin: a time-resolved fluorescence depolarization study. J Mol Biol 2003; 328:705-19. [PMID: 12706727 DOI: 10.1016/s0022-2836(03)00326-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The conformation of the AB-loop and EF-loop of bacteriorhodopsin and of the fourth cytoplasmic loop (helix VIII) of bovine rhodopsin were assessed by a combination of time-resolved fluorescence depolarization and site-directed fluorescence labeling. The fluorescence anisotropy decays were measured employing a tunable Ti:sapphire laser/microchannel plate based single-photon counting apparatus with picosecond time resolution. This method allows measurement of the diffusional dynamics of the loops directly on a nanosecond time-scale. We implemented the method to study model peptides and two-helix systems representing sequences of bacteriorhodopsin. Thus, we systematically analyzed the anisotropic behavior of four different fluorescent dyes covalently bound to a single cysteine residue on the protein surface and assigned the anisotropy decay components to the modes of motion of the protein and its segments. We have identified two mechanisms of loop conformational changes in the functionally intact proteins bacteriorhodopsin and bovine rhodopsin. First, we found a surface potential-dependent transition between two conformational states of the EF-loop of bacteriorhodopsin, detected with the fluorescent dye bound to position 160. A transition between the two conformational states at 150mM KCl and 20 degrees C requires a surface potential change that corresponds to Deltasigma approximately -1.0e(-)/bacteriorhodopsin molecule. We suggest, that the surface potential-based switch of the EF-loop is the missing link between the movement of helix F and the transient surface potential change detected during the photocycle of bacteriorhodopsin. Second, in the visual pigment rhodopsin, with the fluorescent dye bound to position 316, a particularly striking pH-dependent conformational change of the fourth loop on the cytoplasmic surface was analyzed. The loop mobility increased from pH 5 to 8. The midpoint of this transition is at pH 6.2 and correlates with the midpoint of the pH-dependent equilibrium between the active metarhodopsin II and the inactive metarhodopsin I state.
Collapse
Affiliation(s)
- U Alexiev
- Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | | | | |
Collapse
|
31
|
Kalinin S, Molotkovsky JG, Johansson LBÅ. Distance Measurements Using Partial Donor−Donor Energy Migration within Pairs of Fluorescent Groups in Lipid Bilayers. J Phys Chem B 2003. [DOI: 10.1021/jp022672c] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stanislav Kalinin
- Department of Chemistry, Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden, and Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117988 Moscow, Russia
| | - Julian G. Molotkovsky
- Department of Chemistry, Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden, and Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117988 Moscow, Russia
| | - Lennart B.-Å. Johansson
- Department of Chemistry, Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden, and Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117988 Moscow, Russia
| |
Collapse
|
32
|
Tleugabulova D, Zhang Z, Brennan JD. Characterization of Bodipy Dimers Formed in a Molecularly Confined Environment. J Phys Chem B 2002. [DOI: 10.1021/jp027126y] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dina Tleugabulova
- Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1 Canada
| | - Zheng Zhang
- Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1 Canada
| | - John D. Brennan
- Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1 Canada
| |
Collapse
|
33
|
Kalinin SV, Molotkovsky JG, Johansson LBA. Partial donor-donor energy migration (PDDEM) as a fluorescence spectroscopic tool for measuring distances in biomacromolecules. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2002; 58:1087-1097. [PMID: 11942395 DOI: 10.1016/s1386-1425(01)00613-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A theoretical model is presented, tested and applied for determining the rates of energy migration and distances within pairs of chemically identical fluorophores, so-called donors (D), which are exposed to different physical properties. The model is a general extension of the recently developed donor-donor energy migration (DDEM) model [J. Chem. Soc., Faraday Trans. 92 (1996)1563; J. Chem. Phys. 105 (1996) 10896] that applies to examining structure-function of biomacromolecules, such as proteins. Most fluorescent groups of the same kind incorporated at different positions (alpha and beta) in a macromolecule exhibit shifts of the absorption and/or emission spectra, as well as different relaxation rates of the photophysics. As a consequence, the energy migration between the D(alpha) and D(beta) groups will be partially reversible. We refer to this case, as the partial donor-donor energy migration (PDDEM). The models of PPDEM presented can be used for analysing time-resolved fluorescence relaxation, as well as fluorescence depolarisation experiments. To explore the limitations of the PDDEM model, we have generated and re-analysed synthetic data that mimic time-correlated single photon counting (TCSPC) experiments. It was found that slow and fast rates of energy migration are most accurately recovered from the fluorescence relaxation and the depolarisation experiments, respectively. At comparable transfer and fluorescence rates, both kinds of experiments are equally useful. Real experiments on PDDEM were performed on an asymmetrically quenched bichromophoric molecule (1,32-dihydroxy-dotriacontane-bis-(Rhodamine 101) ester), that spans across the lipid bilayer of a vesicle. The depolarisation data were analysed by the PDDEM model and provide a distance between Rhodamine 101 groups, which agrees with independent studies.
Collapse
|
34
|
Bergström F, Mikhalyov I, Hägglöf P, Wortmann R, Ny T, Johansson LBA. Dimers of dipyrrometheneboron difluoride (BODIPY) with light spectroscopic applications in chemistry and biology. J Am Chem Soc 2002; 124:196-204. [PMID: 11782171 DOI: 10.1021/ja010983f] [Citation(s) in RCA: 263] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A ground-state dimer (denoted D(I)) exhibiting a strong absorption maximum at 477 nm (epsilon = 97 000 M(-1)cm(-1)) can form between adjacent BODIPY groups attached to mutant forms of the protein, plasminogen activator inhibitor type 1 (PAI-1). No fluorescence from excited D(I) was detected. A locally high concentration of BODIPY groups was also achieved by doping lipid phases (micelles, vesicles) with BODIPY-labeled lipids. In addition to an absorption band located at about 480 nm, a new weak absorption band is also observed at ca. 570 nm. Both bands are ascribed to the formation of BODIPY dimers of different conformation (D(I) and D(II)). Contrary to D(I) in PAI-1, the D(II) aggregates absorbing at 570 nm are emitting light observed as a broad band centered at about 630 nm. The integrated absorption band of D(I) is about twice that of the monomer, which is compatible with exciton coupling within a dimer. The Förster radius of electronic energy transfer between a BODIPY excited monomer and the ground-state dimer (D(I)()) is 57 +/- 2 A. A simple model of exciton coupling suggests that in D(I) two BODIPY groups are stacked on top of each other in a sandwich-like configuration with parallel electronic transition dipoles. For D(II) the model suggests that the S(0) --> S(1) transition dipoles are colinear. An explanation for the previously reported (J. Am. Chem. Soc. 1994, 116, 7801) exceptional light spectroscopic properties of BODIPY is also presented. These are ascribed to the extraordinary electric properties of the BODIPY chromophore. First, changes of the permanent electric dipole moment (Delta(mu) approximately -0.05 D) and polarizability (-26 x 10(-40) C m(2) V(-1)) between the ground and the first excited states are small. Second, the S(0) <--> S(1) electronic transition dipole moments are perpendicular to Delta(mu).
Collapse
Affiliation(s)
- Fredrik Bergström
- Department of Chemistry, Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden
| | | | | | | | | | | |
Collapse
|
35
|
Rzeska A, Malicka J, Guzow K, Szabelski M, Wiczk W. New highly fluorescent amino-acid derivatives. J Photochem Photobiol A Chem 2001. [DOI: 10.1016/s1010-6030(01)00591-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
36
|
Mikhalyov I, Bogen ST, Johansson LB. Donor-donor energy migration (DDEM) as a tool for studying aggregation in lipid phases. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2001; 57:1839-1845. [PMID: 11506035 DOI: 10.1016/s1386-1425(01)00411-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A BODIPY-labelled sulfatide (N-(BODIPY-FL-pentanoyl)-galactosylcerebroside-sulfate, hereafter abbreviated as BD-Sulfatide) was solubilised at different concentrations in lipid vesicles of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). Time-correlated single photon counting experiments show that the fluorescence relaxation is mono-exponential (with a lifetime of 6.5 ns) at molar ratios of BD-Sulfatide: DOPC that are less than 1:100. The fluorescence steady-state anisotropy decreases monotonously at molar ratios smaller than 1:1000, which is compatible with donor-donor energy migration (DDEM) among the BODIPY groups. A model that assumes DDEM across the lipid bilayers, as well as in their planes, was used to analyse the time-resolved fluorescence anisotropy. Only two parameters appear in the model namely: the bilayer thickness (d) and the average number density (C2) distribution of BD-Sulfatide in the lipid bilayers. The extracted d-values vary between 35 and 40 A, which is about the reported thickness of a bilayer of DOPC (38 A). Hence, the BODIPY groups are preferentially located in the water-lipid interface. At low concentration the experimental C2-values and those independently calculated are in good agreement, while the experimental values gradually become lower with increasing BD-Sulfatide concentration. These results are compatible with an aggregation of the sulfatides and self-quenching of BODIPY, which is clearly established at higher concentrations of the BD-Sulfatide.
Collapse
Affiliation(s)
- I Mikhalyov
- Department of Chemistry: Biophysical Chemistry, Umeå University, Sweden
| | | | | |
Collapse
|
37
|
Stout TJ, Graham H, Buckley DI, Matthews DJ. Structures of active and latent PAI-1: a possible stabilizing role for chloride ions. Biochemistry 2000; 39:8460-9. [PMID: 10913251 DOI: 10.1021/bi000290w] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Serpins exhibit a range of physiological roles and can contribute to certain disease states dependent on their various conformations. Understanding the mechanisms of the large-scale conformational reorganizations of serpins may lead to a better understanding of their roles in various cardiovascular diseases. We have studied the serpin, plasminogen activator inhibitor 1 (PAI-1), in both the active and the latent state and found that anionic halide ions may play a role in the active-to-latent structural transition. Crystallographic analysis of a stable mutant form of active PAI-1 identified an anion-binding site between the central beta-sheet and a small surface domain. A chloride ion was modeled in this site, and its identity was confirmed by soaking crystals in a bromide-containing solution and calculating a crystallographic difference map. The anion thus located forms a 4-fold ligated linchpin that tethers the surface domain to the central beta-sheet into which the reactive center loop must insert during the active-to-latent transition. Timecourse experiments measuring active PAI-1 stability in the presence of various halide ions showed a clear trend for stabilization of the active form with F(-) > Cl(-) > Br(-) >> I(-). We propose that the "stickiness" of this pin (i.e., the electronegativity of the anion) contributes to the energetics of the active-to-latent transition in the PAI-1 serpin.
Collapse
Affiliation(s)
- T J Stout
- MetaXen, South San Francisco, CA 94080, USA.
| | | | | | | |
Collapse
|
38
|
Fa M, Bergström F, Karolin J, Johansson LB, Ny T. Conformational studies of plasminogen activator inhibitor type 1 by fluorescence spectroscopy. Analysis of the reactive centre of inhibitory and substrate forms, and of their respective reactive-centre cleaved forms. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:3729-34. [PMID: 10848991 DOI: 10.1046/j.1432-1327.2000.01406.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The inhibitors that belong to the serpin family are suicide inhibitors that control the major proteolytic cascades in eucaryotes. Recent data suggest that serpin inhibition involves reactive centre cleavage followed by loop insertion, whereby the covalently linked protease is translocated away from the initial docking site. However under certain circumstances, serpins can also be cleaved like a substrate by target proteases. In this report we have studied the conformation of the reactive centre of plasminogen activator inhibitor type 1 (PAI-1) mutants with inhibitory and substrate properties. The polarized steady-state and time-resolved fluorescence anisotropies were determined for BODIPY(R) probes attached to the P1' and P3 positions of the substrate and active forms of PAI-1. The fluorescence data suggest an extended orientational freedom of the probe in the reactive centre of the substrate form as compared to the active form, revealing that the conformation of the reactive centres differ. The intramolecular distance between the P1' and P3 residues in reactive centre cleaved inhibitory and substrate mutants of PAI-1, were determined by using the donor-donor energy migration (DDEM) method. The distances found were 57+/-4 A and 63+/-3 A, respectively, which is comparable to the distance obtained between the same residues when PAI-1 is in complex with urokinase-type plasminogen activator (uPA). Following reactive centre cleavage, our data suggest that the core of the inhibitory and substrate forms possesses an inherited ability of fully inserting the reactive centre loop into beta-sheet A. In the inhibitory forms of PAI-1 forming serpin-protease complexes, this ability leads to a translocation of the cognate protease from one pole of the inhibitor to the opposite one.
Collapse
Affiliation(s)
- M Fa
- Department of Medical Biosciences, Medical Biochemistry, Umeå University, Sweden
| | | | | | | | | |
Collapse
|
39
|
Fa M, Bergström F, Hägglöf P, Wilczynska M, Johansson LB, Ny T. The structure of a serpin-protease complex revealed by intramolecular distance measurements using donor-donor energy migration and mapping of interaction sites. Structure 2000; 8:397-405. [PMID: 10801484 DOI: 10.1016/s0969-2126(00)00121-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND The inhibitors that belong to the serpin family are widely distributed regulatory molecules that include most protease inhibitors found in blood. It is generally thought that serpin inhibition involves reactive-centre cleavage, loop insertion and protease translocation, but different models of the serpin-protease complex have been proposed. In the absence of a spatial structure of a serpin-protease complex, a detailed understanding of serpin inhibition and the character of the virtually irreversible complex have remained controversial. RESULTS We used a recently developed method for making precise distance measurements, based on donor-donor energy migration (DDEM), to accurately triangulate the position of the protease urokinase-type plasminogen activator (uPA) in complex with the serpin plasminogen activator inhibitor type 1 (PAI-1). The distances from residue 344 (P3) in the reactive-centre loop of PAI-1 to residues 185, 266, 313 and 347 (P1') were determined. Modelling of the complex using this distance information unequivocally placed residue 344 in a position at the distal end from the initial docking site with the reactive-centre loop fully inserted into beta sheet A. To validate the model, seven single cysteine substitution mutants of PAI-1 were used to map sites of protease-inhibitor interaction by fluorescence depolarisation measurements of fluorophores attached to these residues and cross-linking using a sulphydryl-specific cross-linker. CONCLUSIONS The data clearly demonstrate that serpin inhibition involves reactive-centre cleavage followed by full-loop insertion whereby the covalently linked protease is translocated from one pole of the inhibitor to the opposite one.
Collapse
Affiliation(s)
- M Fa
- Department of Medical Biosciences, Medical Biochemistry, Umeâ University, Umeâ, S-90187, Sweden
| | | | | | | | | | | |
Collapse
|
40
|
Bergström F, Hägglöf P, Karolin J, Ny T, Johansson LB. The use of site-directed fluorophore labeling and donor-donor energy migration to investigate solution structure and dynamics in proteins. Proc Natl Acad Sci U S A 1999; 96:12477-81. [PMID: 10535947 PMCID: PMC22954 DOI: 10.1073/pnas.96.22.12477] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The use of molecular genetics for introducing fluorescent molecules enables the use of donor-donor energy migration to determine intramolecular distances in a variety of proteins. This approach can be applied to examine the overall molecular dimensions of proteins and to investigate structural changes upon interactions with specific target molecules. In this report, the donor-donor energy migration method is demonstrated by experiments with the latent form of plasminogen activator inhibitor type 1. Based on the known x-ray structure of plasminogen activator inhibitor type 1, three positions forming the corners of a triangle were chosen. Double Cys substitution mutants (V106C-H185C, H185C-M266C, and M266C-V106C) and corresponding single substitution mutants (V106C, H185C, and M266C) were created and labeled with a sulfhydryl specific derivative of BODIPY (=the D molecule). The side lengths of this triangle were obtained from analyses of the experimental data. The analyses account for the local anisotropic order and rotational motions of the D molecules, as well as for the influence of a partial DD-labeling. The distances, as determined from x-ray diffraction, between the C(alpha)-atoms of the positions V106C-H185C, H185C-M266C, and M266C-V106C were 60.9, 30.8, and 55.1 A, respectively. These are in good agreement with the distances of 54 +/- 4, 38 +/- 3, and 55 +/- 3 A, as determined between the BODIPY groups attached via linkers to the same residues. Although the positions of the D-molecules and the C(alpha)-atoms physically cannot coincide, there is a reasonable agreement between the methods.
Collapse
Affiliation(s)
- F Bergström
- Department of Chemistry, Umeâ University, S-901 87 Umeâ, Sweden
| | | | | | | | | |
Collapse
|
41
|
Dobrikov MI, Bichenkova EV, Douglas KT, Gainutdinov TI, Vlassov VV. Structure of photoreactive binary system of oligonucleotide conjugates assembled on the target nucleotide sequence. J Biomol Struct Dyn 1999; 17:213-21. [PMID: 10563571 DOI: 10.1080/07391102.1999.10508354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Recently we have developed an approach to superspecific photomodification of nucleic acids by binary systems of oligonucleotides conjugated to precursor groups capable of assembling into photoactivatable structure upon simultaneous binding of the conjugates to the target. We have investigated the solution structure of a model binary system 1:2:3, where 1 is the target 12-mer 5'-pdGTATCAGTTTCT, 2 is the photoreactive conjugate 5'-dAGAAACp-NH(CH2)2NH-Az and 3 is the sensitizing conjugate 5'-Pyr-pdTGATAC (Az is p-azidotetrafluorobenzoyl group and Pyr is the pyrenyl-1-methylamino group). The photoreaction within this complex results in crosslinking of reagent 2 with N7-position of the G7 residue of the target thus indicating that the photoreactive Az residue is located in the major groove near the G7 residue. The center-to-center distances between the Pyr and Az moieties in complex 1:2:3 independently determined by the Pyr-group fluorescence quenching and the Az-group sensitized photodecomposition were 11.2 and 12.6 A, respectively.
Collapse
Affiliation(s)
- M I Dobrikov
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Novosibirsk.
| | | | | | | | | |
Collapse
|
42
|
Grechishnikova IV, Bergström F, Johansson LBÅ, Brown RE, Molotkovsky JG. New fluorescent cholesterol analogs as membrane probes. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1420:189-202. [PMID: 10446302 PMCID: PMC4004019 DOI: 10.1016/s0005-2736(99)00088-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
New fluorescent cholesterol analogs, (22E, 20R)-3beta-hydroxy-23-(9-anthryl)-24-norchola-5,22-die ne (R-AV-Ch), and the 20S-isomer (S-AV-Ch) were synthesized, their spectral and membrane properties were characterized. The probes bear a 9-anthrylvinyl (AV) group instead of C22-C27 segment of the cholesterol alkyl chain. Computer simulations show that both of the probes have bulkier tail regions than cholesterol and predict some perturbation in the packing of membranes, particularly for R-AV-Ch. In monolayer experiments, the force-area behavior of the probes was compared with that of cholesterol, pure and in mixtures with palmitoyloleoyl phosphatidylcholine (POPC) and N-stearoyl sphingomyelin (SSM). The results show that pure R-AV-Ch occupies 35-40% more cross-sectional area than cholesterol at surface pressures below film collapse (0-22 mN/m); whereas S-AV-Ch occupies nearly the same molecular area as cholesterol. Isotherms of POPC or SSM mixed with 0.1 mol fraction of either probe are similar to isotherms of the corresponding mixtures of POPC or SSM with cholesterol. The probes show typical AV absorption (lambda 386, 368, 350 and 256 nm) and fluorescence (lambda 412-435 nm) spectra. Steady-state anisotropies of R-AV-Ch and S-AV-Ch in isotropic medium or liquid-crystalline bilayers are higher than the values obtained for other AV probes reflecting hindered intramolecular mobility of the fluorophore and decreased overall rotational rate of the rigid cholesterol derivatives. This suggestion is confirmed by time-resolved fluorescence experiments which show also, in accordance with monolayer data, that S-AV-Ch is better accommodated in POPC-cholesterol bilayers than R-AV-Ch. Model and natural membranes can be labeled by either injecting the probes via a water-soluble organic solvent or by co-lyophilizing probe and phospholipid prior to vesicle production. Detergent-solubilization studies involving 'raft' lipids showed that S-AV-Ch almost identically mimicked the behavior of cholesterol and that of R-AV-Ch was only slightly inferior. Overall, the data suggest that the AV-labeled cholesterol analogs mimic cholesterol behavior in membrane systems and will be useful in related studies.
Collapse
Affiliation(s)
- Irina V. Grechishnikova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow 117871, Russian Federation
| | - Fredric Bergström
- Department of Physical Chemistry, Umeå University, S-901 87 Umeå, Sweden
| | | | | | - Julian G. Molotkovsky
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow 117871, Russian Federation
- Corresponding author. Fax: +7-095-330-6601;
| |
Collapse
|
43
|
Larive CK, Lunte SM, Zhong M, Perkins MD, Wilson GS, Gokulrangan G, Williams T, Afroz F, Schöneich C, Derrick TS, Middaugh CR, Bogdanowich-Knipp S. Separation and analysis of peptides and proteins. Anal Chem 1999; 71:389R-423R. [PMID: 10409086 DOI: 10.1021/a1990013o] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C K Larive
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Protein and peptide interactions with lipids: Structure, membrane function and new methods. Curr Opin Colloid Interface Sci 1998. [DOI: 10.1016/s1359-0294(98)80024-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
45
|
Blackman SM, Piston DW, Beth AH. Oligomeric state of human erythrocyte band 3 measured by fluorescence resonance energy homotransfer. Biophys J 1998; 75:1117-30. [PMID: 9675213 PMCID: PMC1299786 DOI: 10.1016/s0006-3495(98)77601-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The oligomeric state of the erythrocyte anion exchange protein, band 3, has been assayed by resonance energy homotransfer. Homotransfer between oligomeric subunits, labeled with eosin-5-maleimide at Lys430 in the transmembrane domain, has been demonstrated by steady-state and time-resolved fluorescence spectroscopy, and is readily observed by its depolarization of the eosin fluorescence. Polarized fluorescence measurements of HPLC-purified band 3 oligomers indicate that eosin homotransfer increases progressively with increasing species size. This shows that homotransfer also occurs between labeled band 3 dimers as well as within the dimers, making fluorescence anisotropy measurements sensitive to band 3 self-association. Treatment of ghost membranes with either Zn2+ or melittin, agents that cluster band 3, significantly decreases the anisotropy as a result of the increased homotransfer within the band 3 clusters. By comparison with the anisotropy of species of known oligomeric state, the anisotropy of erythrocyte ghost membranes at 37 degrees C is consistent with dimeric and/or tetrameric band 3, and does not require postulation of a fraction of large clusters. Proteolytic removal of the cytoplasmic domain of band 3, which significantly increases the rotational mobility of the transmembrane domain, does not affect its oligomeric state, as reported by eosin homotransfer. These results support a model in which interaction with the membrane skeleton restricts the mobility of band 3 without significantly altering its self-association state.
Collapse
Affiliation(s)
- S M Blackman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232-0615 USA
| | | | | |
Collapse
|