Abstract
Weak up-converted fluorescence related to bacteriochlorophyll a was recorded from various detergent-isolated and membrane-embedded light-harvesting pigment–protein complexes as well as from the functional membranes of photosynthetic purple bacteria under continuous-wave infrared laser excitation at 1064 nm, far outside the optically allowed singlet absorption bands of the chromophore. The fluorescence increases linearly with the excitation power, distinguishing it from the previously observed two-photon excited fluorescence upon femtosecond pulse excitation. Possible mechanisms of this excitation are discussed.
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Alden RG, Johnson E, Nagarajan V et al (1997) Calculations of spectroscopic properties of the LH2 bacteriochlorophyll—protein antenna complex from Rhodopseudomonas acidophila. J Phys Chem B 101:4667–4680. doi:10.1021/jp970005r
Ashikhmin A, Makhneva Z, Moskalenko A (2014) The LH2 complexes are assembled in the cells of purple sulfur bacterium Ectothiorhodospira haloalkaliphila with inhibition of carotenoid biosynthesis. Photosynth Res 119:291–303. doi:10.1007/s11120-013-9947-6
Ashkin A (1970) Acceleration and trapping of particles by radiation pressure. Phys Rev Lett 24:156–159. doi:10.1103/PhysRevLett.24.156
Beekman LMP, Frese RN, Fowler GJS et al (1997) Characterization of the light-harvesting antennas of photosynthetic purple bacteria by Stark spectroscopy. 2. LH2 complexes: influence of the protein environment. J Phys Chem B 101:7293–7301. doi:10.1021/jp963447w
Bittl R, Schlodder E, Geisenheimer I et al (2001) Transient EPR and absorption studies of carotenoid triplet formation in purple bacterial antenna complexes. J Phys Chem B 105:5525–5535. doi:10.1021/jp0033014
Bopp MA, Jia Y, Li L et al (1997) Fluorescence and photobleaching dynamics of single light-harvesting complexes. Proc Natl Acad Sci 94:10630–10635. doi:10.1073/pnas.94.20.10630
Clayton RK, Clayton BJ (1981) B850 pigment-protein complex of Rhodopseudomonas sphaeroides: extinction coefficients, circular dichroism, and the reversible binding of bacteriochlorophyll. Proc Natl Acad Sci 78:5583–5587
Frank HA, Cogdell RJ (1996) Carotenoids in photosynthesis. Photochem Photobiol 63:257–264. doi:10.1111/j.1751-1097.1996.tb03022.x
Freiberg A, Rätsep M, Timpmann K et al (2003) Self-trapped excitons in LH2 antenna complexes between 5 K and ambient temperature. J Phys Chem B 107:11510–11519. doi:10.1021/jp0344848
Freiberg A, Rätsep M, Timpmann K, Trinkunas G (2009) Excitonic polarons in quasi-one-dimensional LH1 and LH2 bacteriochlorophyll a antenna aggregates from photosynthetic bacteria: a wavelength-dependent selective spectroscopy study. Chem Phys 357:102–112. doi:10.1016/j.chemphys.2008.10.043
Freiberg A, Timpmann K, Trinkunas G (2010) Spectral fine-tuning in excitonically coupled cyclic photosynthetic antennas. Chem Phys Lett 500:111–115. doi:10.1016/j.cplett.2010.09.084
Freiberg A, Rätsep M, Timpmann K (2012) A comparative spectroscopic and kinetic study of photoexcitations in detergent-isolated and membrane-embedded LH2 light-harvesting complexes. Biochim Biophys Acta BBA—Bioenerg 1817:1471–1482. doi:10.1016/j.bbabio.2011.11.019
Freiberg A, Pajusalu M, Rätsep M (2013) Excitons in intact cells of photosynthetic bacteria. J Phys Chem B 117:11007–11014. doi:10.1021/jp3098523
Hartzler DA, Niedzwiedzki DM, Bryant DA et al (2014) Triplet excited state energies and phosphorescence spectra of (bacterio) chlorophylls. J Phys Chem B 118:7221–7232. doi:10.1021/jp500539w
Koyama Y, Kakitani Y, Limantara L, Fujii R (2006) Effects of axial coordination, electronic excitation and oxidation on bond orders in the bacteriochlorin macrocycle, and generation of radical cation on photo-excitation of in vitro and in vivo bacteriochlorophyll a aggregates: resonance Raman studies. In: Grimm B, Porra RJ, Rüdiger W, Scheer H (eds) Chlorophylls Bacteriochlorophylls. Springer, Netherlands, pp 323–335
Krasnovski AAJ (2014) Phosphorescence of triplet chlorophylls. In: Kadish KM, Smith KM, Guilard R (eds) Handbook of porphyrin science. World Scientific Publishing, Hackensack, pp 77–166
Krikunova M, Kummrow A, Voigt B et al (2002) Fluorescence of native and carotenoid-depleted LH2 from Chromatium minutissimum, originating from simultaneous two-photon absorption in the spectral range of the presumed (optically “dark”) S 1 state of carotenoids. FEBS Lett 528:227–229. doi:10.1016/S0014-5793(02)03315-X
Krueger BP, Yom J, Walla PJ, Fleming GR (1999) Observation of the S 1 state of spheroidene in LH2 by two-photon fluorescence excitation. Chem Phys Lett 310:57–64. doi:10.1016/S0009-2614(99)00729-0
Kunz R, Timpmann K, Southall J et al (2013) Fluorescence-excitation and emission spectra from LH2 antenna complexes of Rhodopseudomonas acidophila as a function of the sample preparation conditions. J Phys Chem B 117:12020–12029. doi:10.1021/jp4073697
Leiger K, Reisberg L, Freiberg A (2013) Fluorescence micro-spectroscopy study of individual photosynthetic membrane vesicles and light-harvesting complexes. J Phys Chem B 117:9315–9326. doi:10.1021/jp4014509
Leupold D, Teuchner K, Ehlert J et al (2002) Two-photon excited fluorescence from higher electronic states of chlorophylls in photosynthetic antenna complexes: a new approach to detect strong excitonic chlorophyll a/b coupling. Biophys J 82:1580–1585. doi:10.1016/S0006-3495(02)75509-4
Leupold D, Teuchner K, Ehlert J et al (2006) Stepwise two-photon excited fluorescence from higher excited states of chlorophylls in photosynthetic antenna complexes. J Biol Chem 281:25381–25387. doi:10.1074/jbc.M600080200
Linnanto J, Freiberg A, Korppi-Tommola J (2011) Quantum chemical simulations of excited-state absorption spectra of photosynthetic bacterial reaction center and antenna complexes. J Phys Chem B 115:5536–5544. doi:10.1021/jp111340w
Liu Y, Berns MW, Konig K et al (1995a) Two-photon fluorescence excitation in continuous-wave infrared optical tweezers. Opt Lett 20:2246–2248. doi:10.1364/OL.20.002246
Liu Y, Cheng DK, Sonek GJ et al (1995b) Evidence for localized cell heating induced by infrared optical tweezers. Biophys J 68:2137–2144. doi:10.1016/S0006-3495(95)80396-6
Liu Y, Sonek GJ, Berns MW, Tromberg BJ (1996) Physiological monitoring of optically trapped cells: assessing the effects of confinement by 1064-nm laser tweezers using microfluorometry. Biophys J 71:2158–2167. doi:10.1016/S0006-3495(96)79417-1
Lower SK, El-Sayed MA (1966) The triplet state and molecular electronic processes in organic molecules. Chem Rev 66:199–241. doi:10.1021/cr60240a004
Monger TG, Cogdell RJ, Parson WW (1976) Triplet states of bacteriochlorophyll and carotenoids in chromatophores of photosynthetic bacteria. Biochim Biophys Acta BBA—Bioenerg 449:136–153. doi:10.1016/0005-2728(76)90013-X
Niedzwiedzki DM, Blankenship RE (2010) Singlet and triplet excited state properties of natural chlorophylls and bacteriochlorophylls. Photosynth Res 106:227–238. doi:10.1007/s11120-010-9598-9
Perkins TT (2009) Optical traps for single molecule biophysics: a primer. Laser Photonics Rev 3:203–220. doi:10.1002/lpor.200810014
Pflock TJ, Oellerich S, Southall J et al (2011) The electronically excited states of LH2 complexes from Rhodopseudomonas acidophila strain 10050 studied by time-resolved spectroscopy and dynamic Monte Carlo simulations. I. Isolated, non-interacting LH2 complexes. J Phys Chem B 115:8813–8820. doi:10.1021/jp202353c
Pilát Z, Ježek J, Šerý M et al (2013) Optical trapping of microalgae at 735–1064 nm: photodamage assessment. J Photochem Photobiol B 121:27–31. doi:10.1016/j.jphotobiol.2013.02.006
Polívka T, Sundström V (2004) Ultrafast dynamics of carotenoid excited states—from solution to natural and artificial systems. Chem Rev 104:2021–2072. doi:10.1021/cr020674n
Rätsep M, Wu H-M, Hayes JM et al (1998) Stark hole-burning studies of three photosynthetic complexes. J Phys Chem B 102:4035–4044. doi:10.1021/jp980421r
Rätsep M, Cai Z-L, Reimers JR, Freiberg A (2011) Demonstration and interpretation of significant asymmetry in the low-resolution and high-resolution Q y fluorescence and absorption spectra of bacteriochlorophyll a. J Chem Phys 134:024506. doi:10.1063/1.3518685
Rätsep M, Pajusalu M, Linnanto JM, Freiberg A (2014) Subtle spectral effects accompanying the assembly of bacteriochlorophylls into cyclic light harvesting complexes revealed by high-resolution fluorescence spectroscopy. J Chem Phys 141:155102. doi:10.1063/1.4897637
Rondonuwu FS, Taguchi T, Fujii R et al (2004) The energies and kinetics of triplet carotenoids in the LH2 antenna complexes as determined by phosphorescence spectroscopy. Chem Phys Lett 384:364–371. doi:10.1016/j.cplett.2003.12.024
Sauer K, Cogdell RJ, Prince SM et al (1996) Structure-based calculations of the optical spectra of the LH2 bacteriochlorophyll-protein complex from Rhodopseudomonas acidophila. Photochem Photobiol 64:564–576. doi:10.1111/j.1751-1097.1996.tb03106.x
Schneckenburger H, Hendinger A, Sailer R et al (2000) Cell viability in optical tweezers: high power red laser diode versus Nd:YAG laser. J Biomed Opt 5:40–44. doi:10.1117/1.429966
Scholes GD, Gould IR, Cogdell RJ, Fleming GR (1999) Ab initio molecular orbital calculations of electronic couplings in the LH2 bacterial light-harvesting complex of Rps. acidophila. J Phys Chem B 103:2543–2553. doi:10.1021/jp9839753
Şener M, Hsin J, Trabuco LG et al (2009) Structural model and excitonic properties of the dimeric RC–LH1–PufX complex from Rhodobacter sphaeroides. Chem Phys 357:188–197. doi:10.1016/j.chemphys.2009.01.003
Siebert CA, Qian P, Fotiadis D et al (2004) Molecular architecture of photosynthetic membranes in Rhodobacter sphaeroides: the role of PufX. EMBO J 23:690–700. doi:10.1038/sj.emboj.7600092
Stepanenko I, Kompanetz V, Makhneva Z et al (2009) Two-photon excitation spectroscopy of carotenoid-containing and carotenoid-depleted LH2 complexes from purple bacteria. J Phys Chem B 113:11720–11723. doi:10.1021/jp906565m
Stepanenko IA, Kompanets VO, Chekalin SV et al (2010) Photosynthetic light-harvesting complexes: fluorescent and absorption spectroscopy under two-photon (1200–1500 nm) and one-photon (600–750 nm) excitation by laser femtosecond pulses. Proc SPIE 7994:79941C. doi:10.1117/12.882498
Stepanenko I, Kompanetz V, Makhneva Z et al (2012) Transient absorption study of two-photon excitation mechanism in the LH2 complex from purple bacterium Rhodobacter sphaeroides. J Phys Chem B 116:2886–2890. doi:10.1021/jp2033214
Sternlicht H, Nieman GC, Robinson GW (1963) Triplet–triplet annihilation and delayed fluorescence in molecular aggregates. J Chem Phys 38:1326–1335. doi:10.1063/1.1733853
Takiff L, Boxer SG (1988) Phosphorescence spectra of bacteriochlorophylls. J Am Chem Soc 110:4425–4426. doi:10.1021/ja00221a059
Timpmann K, Ellervee A, Pullerits T et al (2001) Short-range exciton couplings in LH2 photosynthetic antenna proteins studied by high hydrostatic pressure absorption spectroscopy. J Phys Chem B 105:8436–8444. doi:10.1021/jp003496f
Walz T, Jamieson SJ, Bowers CM et al (1998) Projection structures of three photosynthetic complexes from Rhodobacter sphaeroides: LH2 at 6 Å, LH1 and RC-LH1 at 25 Å. J Mol Biol 282:833–845. doi:10.1006/jmbi.1998.2050
Acknowledgments
This work was supported by the Estonian Research Council (Grant IUT02-28) and the Australian Research Council Discovery Project (Grant DP150103137). The authors thank A. Moskalenko and A. Ashikhmin for kindly providing the Ectothiorhodospira haloalkaliphila samples and I. Proskuryakov for useful discussions.
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Leiger, K., Freiberg, A. Up-converted fluorescence from photosynthetic light-harvesting complexes linearly dependent on excitation intensity. Photosynth Res 127, 77–87 (2016). https://doi.org/10.1007/s11120-015-0117-x
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DOI: https://doi.org/10.1007/s11120-015-0117-x