Robert Blankenship | Washington University in St. Louis (original) (raw)
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Papers by Robert Blankenship
Biochemistry, Dec 2, 2015
Journal of Physical Chemistry B, Jun 14, 2010
Biochemistry, May 25, 2017
Biochemistry, Dec 20, 2016
Journal of Physical Chemistry B, Jun 22, 2015
Journal of the American Society for Mass Spectrometry, Aug 9, 2016
FEBS Letters, Aug 1, 2015
Proceedings of the National Academy of Sciences of the United States of America, Jun 22, 2016
![Research paper thumbnail of Corrigendum to “Spectroscopic studies of two spectral variants of light-harvesting complex 2 (LH2) from the photosynthetic purple sulfur bacterium Allochromatium vinosum” [Biochimica et Biophysica Acta — Bioenergetics (2012): 1817, 1576]](https://attachments.academia-assets.com/119478640/thumbnails/1.jpg)
](Biochimica Et Biophysica Acta - Bioenergetics, 2014
Biochimica et Biophysica Acta (BBA) - Bioenergetics, 2019
Biochimica et biophysica acta, Jul 1, 2018
The major light harvesting antenna in all cyanobacterial species is the phycobilisome (PBS). The ... more The major light harvesting antenna in all cyanobacterial species is the phycobilisome (PBS). The smallest PBS identified to date is that of Acaryochloris marina (A. marina), composed of a single four-hexamer rod. We have determined the crystal structure of phycocyanin (AmPC), the major component of the A. marina PBS (AmPBS) to 2.1 Å. The basic unit of the AmPC is a heterodimer of two related subunits (α and β), and we show that the asymmetric unit contains a superposition of two α and two β isoforms, the products of the simultaneous expression of different genes. This is the first time to our knowledge that isolated proteins crystallized with such identifiable heterogeneity. We believe that the presence of the different isoforms allows the AmPBS to have a significant bathochromic shift in its fluorescence emission spectrum, allowing, in the total absence of allophycocyanin, a better overlap with absorption of the chlorophyll d-containing reaction centers. We show that this bathochro...
Photosynthesis research, Jan 3, 2018
Three photosynthetic membranes, called intra-cytoplasmic membranes (ICMs), from wild-type and the... more Three photosynthetic membranes, called intra-cytoplasmic membranes (ICMs), from wild-type and the ∆pucBA mutant of the purple phototrophic bacterium Rps. palustris were investigated using optical spectroscopy. The ICMs contain identical light-harvesting complex 1-reaction centers (LH1-RC) but have various spectral forms of light-harvesting complex 2 (LH2). Spectroscopic studies involving steady-state absorption, fluorescence, and femtosecond time-resolved absorption at room temperature and at 77 K focused on inter-protein excitation energy transfer. The studies investigated how energy transfer is affected by altered spectral features of the LH2 complexes as those develop under growth at different light conditions. The study shows that LH1 → LH2 excitation energy transfer is strongly affected if the LH2 complex alters its spectroscopic signature. The LH1 → LH2 excitation energy transfer rate modeled with the Förster mechanism and kinetic simulations of transient absorption of the ICM...
Microorganisms, Jan 21, 2017
Rhodoferax antarcticus is an Antarctic purple nonsulfur bacterium and the only characterized anox... more Rhodoferax antarcticus is an Antarctic purple nonsulfur bacterium and the only characterized anoxygenic phototroph that grows best below 20 °C. We present here a high-quality draft genome of Rfx. antarcticus strain ANT.BR(T), isolated from an Antarctic microbial mat. The circular chromosome (3.8 Mbp) of Rfx. antarcticus has a 59.1% guanine + cytosine (GC) content and contains 4036 open reading frames. In addition, the bacterium contains a sizable plasmid (198.6 kbp, 48.4% GC with 226 open reading frames) that comprises about 5% of the total genetic content. Surprisingly, genes encoding light-harvesting complexes 1 and 3 (LH1 and LH3), but not light-harvesting complex 2 (LH2), were identified in the photosynthesis gene cluster of the Rfx. antarcticus genome, a feature that is unique among purple phototrophs. Consistent with physiological studies that showed a strong capacity for nitrogen fixation in Rfx. antarcticus, a nitrogen fixation gene cluster encoding a molybdenum-type nitroge...
Journal of the American Society for Mass Spectrometry, Jan 9, 2016
Native mass spectrometry (MS) is an emerging approach to study protein complexes in their near-na... more Native mass spectrometry (MS) is an emerging approach to study protein complexes in their near-native states and to elucidate their stoichiometry and topology. Here, we report a native MS study of the membrane-embedded reaction center (RC) protein complex from the purple photosynthetic bacterium Rhodobacter sphaeroides. The membrane-embedded RC protein complex is stabilized by detergent micelles in aqueous solution, directly introduced into a mass spectrometer by nano-electrospray (nESI), and freed of detergents and dissociated in the gas phase by collisional activation. As the collision energy is increased, the chlorophyll pigments are gradually released from the RC complex, suggesting that native MS introduces a near-native structure that continues to bind pigments. Two bacteriochlorophyll a pigments remain tightly bound to the RC protein at the highest collision energy. The order of pigment release and their resistance to release by gas-phase activation indicates the strength of ...
Biochemistry, Jan 17, 2015
We report a top-down proteomic analysis of the membrane-bound peripheral light-harvesting complex... more We report a top-down proteomic analysis of the membrane-bound peripheral light-harvesting complex LH2 isolated from the purple photosynthetic bacterium Rhodobacter (Rb.) sphaeroides. The LH2 complex is coded for by the puc operon. The Rb. sphaeroides genome contains two puc operons, designated puc1BAC and puc2BA. Although previous work has shown consistently that the LH2 β polypeptide coded by the Puc2B gene was assembled into LH2 complexes, there are contradictory reports whether the Puc2A polypeptides are incorporated into LH2 complexes. Furthermore, post-translational modifications (PTM) of this protein offer the prospect that it could coordinate bacteriochlorophyll a (Bchl a) by a modified N-terminal residue. Here we describe the LH2-complex components on the basis of electron-capture dissociation (ECD) fragmentation to confirm the identity and sequence of the protein subunits. We found that both gene products of the β polypeptides are expressed and assembled in the mature LH2 c...
FEBS letters, 2015
The peridinin-chlorophyll a-protein (PCP) is one of the major light harvesting complexes (LHCs) i... more The peridinin-chlorophyll a-protein (PCP) is one of the major light harvesting complexes (LHCs) in photosynthetic dinoflagellates. We analyzed the oligomeric state of PCP isolated from the dinoflagellate Symbiodinium, which has received increasing attention in recent years because of its role in coral bleaching. Size-exclusion chromatography (SEC) and small angle neutron scattering (SANS) analysis indicated PCP exists as monomers. Native mass spectrometry (native MS) demonstrated two oligomeric states of PCP, with the monomeric PCP being dominant. The trimerization may not be necessary for PCP to function as a light-harvesting complex.
The Journal of Physical Chemistry B, 2015
Biochemistry, Dec 2, 2015
Journal of Physical Chemistry B, Jun 14, 2010
Biochemistry, May 25, 2017
Biochemistry, Dec 20, 2016
Journal of Physical Chemistry B, Jun 22, 2015
Journal of the American Society for Mass Spectrometry, Aug 9, 2016
FEBS Letters, Aug 1, 2015
Proceedings of the National Academy of Sciences of the United States of America, Jun 22, 2016
Biochimica Et Biophysica Acta - Bioenergetics, 2014
Biochimica et Biophysica Acta (BBA) - Bioenergetics, 2019
Biochimica et biophysica acta, Jul 1, 2018
The major light harvesting antenna in all cyanobacterial species is the phycobilisome (PBS). The ... more The major light harvesting antenna in all cyanobacterial species is the phycobilisome (PBS). The smallest PBS identified to date is that of Acaryochloris marina (A. marina), composed of a single four-hexamer rod. We have determined the crystal structure of phycocyanin (AmPC), the major component of the A. marina PBS (AmPBS) to 2.1 Å. The basic unit of the AmPC is a heterodimer of two related subunits (α and β), and we show that the asymmetric unit contains a superposition of two α and two β isoforms, the products of the simultaneous expression of different genes. This is the first time to our knowledge that isolated proteins crystallized with such identifiable heterogeneity. We believe that the presence of the different isoforms allows the AmPBS to have a significant bathochromic shift in its fluorescence emission spectrum, allowing, in the total absence of allophycocyanin, a better overlap with absorption of the chlorophyll d-containing reaction centers. We show that this bathochro...
Photosynthesis research, Jan 3, 2018
Three photosynthetic membranes, called intra-cytoplasmic membranes (ICMs), from wild-type and the... more Three photosynthetic membranes, called intra-cytoplasmic membranes (ICMs), from wild-type and the ∆pucBA mutant of the purple phototrophic bacterium Rps. palustris were investigated using optical spectroscopy. The ICMs contain identical light-harvesting complex 1-reaction centers (LH1-RC) but have various spectral forms of light-harvesting complex 2 (LH2). Spectroscopic studies involving steady-state absorption, fluorescence, and femtosecond time-resolved absorption at room temperature and at 77 K focused on inter-protein excitation energy transfer. The studies investigated how energy transfer is affected by altered spectral features of the LH2 complexes as those develop under growth at different light conditions. The study shows that LH1 → LH2 excitation energy transfer is strongly affected if the LH2 complex alters its spectroscopic signature. The LH1 → LH2 excitation energy transfer rate modeled with the Förster mechanism and kinetic simulations of transient absorption of the ICM...
Microorganisms, Jan 21, 2017
Rhodoferax antarcticus is an Antarctic purple nonsulfur bacterium and the only characterized anox... more Rhodoferax antarcticus is an Antarctic purple nonsulfur bacterium and the only characterized anoxygenic phototroph that grows best below 20 °C. We present here a high-quality draft genome of Rfx. antarcticus strain ANT.BR(T), isolated from an Antarctic microbial mat. The circular chromosome (3.8 Mbp) of Rfx. antarcticus has a 59.1% guanine + cytosine (GC) content and contains 4036 open reading frames. In addition, the bacterium contains a sizable plasmid (198.6 kbp, 48.4% GC with 226 open reading frames) that comprises about 5% of the total genetic content. Surprisingly, genes encoding light-harvesting complexes 1 and 3 (LH1 and LH3), but not light-harvesting complex 2 (LH2), were identified in the photosynthesis gene cluster of the Rfx. antarcticus genome, a feature that is unique among purple phototrophs. Consistent with physiological studies that showed a strong capacity for nitrogen fixation in Rfx. antarcticus, a nitrogen fixation gene cluster encoding a molybdenum-type nitroge...
Journal of the American Society for Mass Spectrometry, Jan 9, 2016
Native mass spectrometry (MS) is an emerging approach to study protein complexes in their near-na... more Native mass spectrometry (MS) is an emerging approach to study protein complexes in their near-native states and to elucidate their stoichiometry and topology. Here, we report a native MS study of the membrane-embedded reaction center (RC) protein complex from the purple photosynthetic bacterium Rhodobacter sphaeroides. The membrane-embedded RC protein complex is stabilized by detergent micelles in aqueous solution, directly introduced into a mass spectrometer by nano-electrospray (nESI), and freed of detergents and dissociated in the gas phase by collisional activation. As the collision energy is increased, the chlorophyll pigments are gradually released from the RC complex, suggesting that native MS introduces a near-native structure that continues to bind pigments. Two bacteriochlorophyll a pigments remain tightly bound to the RC protein at the highest collision energy. The order of pigment release and their resistance to release by gas-phase activation indicates the strength of ...
Biochemistry, Jan 17, 2015
We report a top-down proteomic analysis of the membrane-bound peripheral light-harvesting complex... more We report a top-down proteomic analysis of the membrane-bound peripheral light-harvesting complex LH2 isolated from the purple photosynthetic bacterium Rhodobacter (Rb.) sphaeroides. The LH2 complex is coded for by the puc operon. The Rb. sphaeroides genome contains two puc operons, designated puc1BAC and puc2BA. Although previous work has shown consistently that the LH2 β polypeptide coded by the Puc2B gene was assembled into LH2 complexes, there are contradictory reports whether the Puc2A polypeptides are incorporated into LH2 complexes. Furthermore, post-translational modifications (PTM) of this protein offer the prospect that it could coordinate bacteriochlorophyll a (Bchl a) by a modified N-terminal residue. Here we describe the LH2-complex components on the basis of electron-capture dissociation (ECD) fragmentation to confirm the identity and sequence of the protein subunits. We found that both gene products of the β polypeptides are expressed and assembled in the mature LH2 c...
FEBS letters, 2015
The peridinin-chlorophyll a-protein (PCP) is one of the major light harvesting complexes (LHCs) i... more The peridinin-chlorophyll a-protein (PCP) is one of the major light harvesting complexes (LHCs) in photosynthetic dinoflagellates. We analyzed the oligomeric state of PCP isolated from the dinoflagellate Symbiodinium, which has received increasing attention in recent years because of its role in coral bleaching. Size-exclusion chromatography (SEC) and small angle neutron scattering (SANS) analysis indicated PCP exists as monomers. Native mass spectrometry (native MS) demonstrated two oligomeric states of PCP, with the monomeric PCP being dominant. The trimerization may not be necessary for PCP to function as a light-harvesting complex.
The Journal of Physical Chemistry B, 2015