dr Rafał Białek

@article{Szewczyk2020,
title = {On the nature of uncoupled chlorophylls in the extremophilic photosystem I-light harvesting I supercomplex},
author = {Sebastian Szewczyk and Mateusz Abram and Rafał Białek and Patrycja Haniewicz and Jerzy Karolczak and Jacek Gapiński and Joanna Kargul and Krzysztof Gibasiewicz},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0005272819301902},
doi = {10.1016/j.bbabio.2019.148136},
issn = {00052728},
year = {2020},
date = {2020-02-01},
journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics},
volume = {1861},
number = {2},
pages = {148136},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Szewczyk2020b,
title = {Excitation dynamics in Photosystem I trapped in TiO2 mesopores},
author = {Sebastian Szewczyk and Rafał Białek and Wojciech Giera and G Burdziński and Rienk van Grondelle and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1007/s11120-020-00730-1 http://link.springer.com/10.1007/s11120-020-00730-1},
doi = {10.1007/s11120-020-00730-1},
issn = {0166-8595},
year = {2020},
date = {2020-02-01},
journal = {Photosynthesis Research},
number = {0123456789},
publisher = {Springer Netherlands},
abstract = {Excitation decay in closed Photosystem I (PSI) isolated from cyanobacterium Synechocystis sp. PCC 6803 and dissolved in a buffer solution occurs predominantly with a ~ 24-ps lifetime, as measured both by time-resolved fluorescence and transient absorption. The same PSI particles deposited in mesoporous matrix made of TiO2 nanoparticles exhibit significantly accelerated excitation decay dominated by a ~ 6-ps component. Target analysis indicates that this acceleration is caused by ~ 50% increase of the rate constant of bulk Chls excitation quenching. As an effect of this increase, as much as ~ 70% of bulk Chls excitation is quenched before the establishment of equilibrium with the red Chls. Accelerated quenching may be caused by increased excitation trapping by the reaction center and/or quenching properties of the TiO2 surface directly interacting with PSI Chls. Also properties of the PSI red Chls are affected by the deposition in the TiO2 matrix: they become deeper traps due to an increase of their number and their oscillator strength is significantly reduced. These effects should be taken into account when constructing solar cells' photoelectrodes composed of PSI and artificial matrices.},
keywords = {Excitation dynamics, Photosystem I, Primary charge separation, Synechocystis, Target analysis, Time-resolved fluorescence, Transient absorption},
pubstate = {published},
tppubtype = {article}
}

@article{Szewczyk2020c,
title = {Photovoltaic activity of electrodes based on intact photosystem I electrodeposited on bare conducting glass},
author = {Sebastian Szewczyk and Rafał Białek and Gotard Burdziński and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1007/s11120-020-00722-1 http://link.springer.com/10.1007/s11120-020-00722-1},
doi = {10.1007/s11120-020-00722-1},
issn = {0166-8595},
year = {2020},
date = {2020-02-01},
journal = {Photosynthesis Research},
number = {0123456789},
publisher = {Springer Netherlands},
keywords = {cyanobacterium synechocystis sp, Cyanobacterium Synechocystis sp. PCC 6803, Femtosecond-transient absorption, FTO conducting glass, pcc 6803, Photoelectrochemical measurements, Photosystem I, Photovoltaics},
pubstate = {published},
tppubtype = {article}
}

@article{Abram2020,
title = {Remodeling of excitation energy transfer in extremophilic red algal PSI-LHCI complex during light adaptation},
author = {Mateusz Abram and Rafał Białek and Sebastian Szewczyk and Jerzy Karolczak and Krzysztof Gibasiewicz and Joanna Kargul},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0005272819301409},
doi = {10.1016/j.bbabio.2019.148093},
issn = {00052728},
year = {2020},
date = {2020-01-01},
journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics},
volume = {1861},
number = {1},
pages = {148093},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Biaek2020,
title = {In situ spectroelectrochemical investigation of a biophotoelectrode based on photoreaction centers embedded in a redox hydrogel},
author = {Rafał Białek and Vincent Friebe and Adrian Ruff and Michael R Jones and Raoul Frese and Krzysztof Gibasiewicz},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0013468619320614},
doi = {10.1016/j.electacta.2019.135190},
issn = {00134686},
year = {2020},
date = {2020-01-01},
journal = {Electrochimica Acta},
volume = {330},
pages = {135190},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{doi:10.1021/acs.jpcb.0c08714,
title = {Insight into Electron Transfer from a Redox Polymer to a Photoactive Protein},
author = {Rafał Białek and Kalyani Thakur and Adrian Ruff and Michael R Jones and Wolfgang Schuhmann and Charusheela Ramanan and Krzysztof Gibasiewicz},
url = {https://doi.org/10.1021/acs.jpcb.0c08714},
doi = {10.1021/acs.jpcb.0c08714},
year = {2020},
date = {2020-01-01},
journal = {The Journal of Physical Chemistry B},
volume = {124},
number = {49},
pages = {11123-11132},
abstract = {Biohybrid photoelectrochemical systems in photovoltaic or biosensor applications have gained considerable attention in recent years. While the photoactive proteins engaged in such systems usually maintain an internal charge separation quantum yield of nearly 100%, the subsequent steps of electron and hole transfer beyond the protein often limit the overall system efficiency and their kinetics remain largely uncharacterized. To reveal the dynamics of one of such charge-transfer reactions, we report on the reduction of Rhodobacter sphaeroides reaction centers (RCs) by Os-complex-modified redox polymers (P-Os) characterized using transient absorption spectroscopy. RCs and P-Os were mixed in buffered solution in different molar ratios in the presence of a water-soluble quinone as an electron acceptor. Electron transfer from P-Os to the photoexcited RCs could be described by a three-exponential function, the fastest lifetime of which was on the order of a few microseconds, which is a few orders of magnitude faster than the internal charge recombination of RCs with fully separated charge. This was similar to the lifetime for the reduction of RCs by their natural electron donor, cytochrome c2. The rate of electron donation increased with increasing ratio of polymer to protein concentrations. It is proposed that P-Os and RCs engage in electrostatic interactions to form complexes, the sizes of which depend on the polymer-to-protein ratio. Our findings throw light on the processes within hydrogel-based biophotovoltaic devices and will inform the future design of materials optimally suited for this application.},
note = {PMID: 33236901},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Szewczyk2018b,
title = {Acceleration of the excitation decay in Photosystem I immobilized on glass surface},
author = {Sebastian Szewczyk and Wojciech Giera and Rafał Białek and Gotard Burdziński and Krzysztof Gibasiewicz},
url = {http://link.springer.com/10.1007/s11120-017-0454-z},
doi = {10.1007/s11120-017-0454-z},
issn = {0166-8595},
year = {2018},
date = {2018-05-01},
journal = {Photosynthesis Research},
volume = {136},
number = {2},
pages = {171-181},
abstract = {textcopyright 2017 The Author(s) Femtosecond transient absorption was used to study excitation decay in monomeric and trimeric cyanobacterial Photosystem I (PSI) being prepared in three states: (1) in aqueous solution, (2) deposited and dried on glass surface (either conducting or non-conducting), and (3) deposited on glass (conducting) surface but being in contact with aqueous solvent. The main goal of this contribution was to determine the reason of the acceleration of the excitation decay in dried PSI deposited on the conducting surface relative to PSI in solution observed previously using time-resolved fluorescence (Szewczyk et al., Photysnth Res 132(2):111–126, 2017). We formulated two alternative working hypotheses: (1) the acceleration results from electron injection from PSI to the conducting surface; (2) the acceleration is caused by dehydration and/or crowding of PSI proteins deposited on the glass substrate. Excitation dynamics of PSI in all three types of samples can be described by three main components of subpicosecond, 3–5, and 20–26 ps lifetimes of different relative contributions in solution than in PSI-substrate systems. The presence of similar kinetic components for all the samples indicates intactness of PSI proteins after their deposition onto the substrates. The kinetic traces for all systems with PSI deposited on substrates are almost identical and they decay significantly faster than the kinetic traces of PSI in solution. We conclude that the accelerated excitation decay in PSI-substrate systems is caused mostly by dense packing of proteins.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Biaek2018,
title = {Modelling of the cathodic and anodic photocurrents from Rhodobacter sphaeroides reaction centres immobilized on titanium dioxide},
author = {Rafał Białek and David J K Swainsbury and Maciej Wiesner and Michael R Jones and Krzysztof Gibasiewicz},
url = {http://link.springer.com/10.1007/s11120-018-0550-8},
doi = {10.1007/s11120-018-0550-8},
issn = {0166-8595},
year = {2018},
date = {2018-01-01},
journal = {Photosynthesis Research},
volume = {0},
number = {0},
pages = {0},
publisher = {Springer Netherlands},
keywords = {Purple bacteria},
pubstate = {published},
tppubtype = {article}
}

@article{Biaek2016,
title = {Bacteriopheophytin triplet state in Rhodobacter sphaeroides reaction centers},
author = {Rafał Białek and Gotard Burdziński and Michael R Jones and Krzysztof Gibasiewicz},
url = {http://link.springer.com/10.1007/s11120-016-0290-6},
doi = {10.1007/s11120-016-0290-6},
issn = {0166-8595},
year = {2016},
date = {2016-08-01},
journal = {Photosynthesis Research},
volume = {129},
number = {2},
pages = {205--216},
publisher = {Springer Netherlands},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Gibasiewicz2016,
title = {Weak temperature dependence of P + H A − recombination in mutant Rhodobacter sphaeroides reaction centers},
author = {Krzysztof Gibasiewicz and Rafał Białek and Maria Pajzderska and Jerzy Karolczak and Gotard Burdziński and Michael R Jones and Klaus Brettel},
url = {http://www.ncbi.nlm.nih.gov/pubmed/26942583 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC4877430 http://link.springer.com/10.1007/s11120-016-0239-9},
doi = {10.1007/s11120-016-0239-9},
issn = {0166-8595},
year = {2016},
date = {2016-06-01},
journal = {Photosynthesis Research},
volume = {128},
number = {3},
pages = {243--258},
abstract = {In contrast with findings on the wild-type Rhodobacter sphaeroides reaction center, biexponential P (+) H A (-) → PH A charge recombination is shown to be weakly dependent on temperature between 78 and 298 K in three variants with single amino acids exchanged in the vicinity of primary electron acceptors. These mutated reaction centers have diverse overall kinetics of charge recombination, spanning an average lifetime from ~2 to ~20 ns. Despite these differences a protein relaxation model applied previously to wild-type reaction centers was successfully used to relate the observed kinetics to the temporal evolution of the free energy level of the state P (+) H A (-) relative to P (+) B A (-) . We conclude that the observed variety in the kinetics of charge recombination, together with their weak temperature dependence, is caused by a combination of factors that are each affected to a different extent by the point mutations in a particular mutant complex. These are as follows: (1) the initial free energy gap between the states P (+) B A (-) and P (+) H A (-) , (2) the intrinsic rate of P (+) B A (-) → PB A charge recombination, and (3) the rate of protein relaxation in response to the appearance of the charge separated states. In the case of a mutant which displays rapid P (+) H A (-) recombination (ELL), most of this recombination occurs in an unrelaxed protein in which P (+) B A (-) and P (+) H A (-) are almost isoenergetic. In contrast, in a mutant in which P (+) H A (-) recombination is relatively slow (GML), most of the recombination occurs in a relaxed protein in which P (+) H A (-) is much lower in energy than P (+) H A (-) . The weak temperature dependence in the ELL reaction center and a YLH mutant was modeled in two ways: (1) by assuming that the initial P (+) B A (-) and P (+) H A (-) states in an unrelaxed protein are isoenergetic, whereas the final free energy gap between these states following the protein relaxation is large (~250 meV or more), independent of temperature and (2) by assuming that the initial and final free energy gaps between P (+) B A (-) and P (+) H A (-) are moderate and temperature dependent. In the case of the GML mutant, it was concluded that the free energy gap between P (+) B A (-) and P (+) H A (-) is large at all times.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}