Photosystem I charge separation in the absence of center A and B. III. Biochemical characterization of a reaction center particle containing P-700 and FX

John H. Golbeck, Kevin G. Parrett, Ann E. McDermott

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

The Photosystem I reaction center is a membrane-bound, multiprotein complex containing a primary electron donor (P-700), a primary electron acceptor (A0), an intermediate electron acceptor (A1) and three membrane-bound iron-sulfur centers (FX, FB, and FA). We reported in part I of this series (Golbeck, J.H. and Cornelius, J.M. (1986) Biochim. Biophys. Acta 849, 16-24) that in the presence of 1% lithium dodecyl sulfate (LDS), the reaction center becomes dissociated, resulting in charge separation and recombination between P-700 and FX without the need for prereduction of FA and FB. In this paper, we report (i) the LDS-induced onset of the 1.2-ms 'fast' phase of the P-700 absorption transient is time-dependent, attaining a maximum 3:1 ratio of 'fast' to 'slow' kinetic phases; (ii) the 'fast' kinetic phase, corresponding to the P-700+ FX- backreaction, is stabilized indefinitely by dilution of the LDS-treated particle followed by ultrafiltration over a YM-100 membrane; (iii) without stabilization, the P-700+ FX- reaction deteriorates, leading to the rise of the long-lived P-700 triplet formed from the P-700+AO- backreaction; (iv) the 'slow' kinetic phase correlates with the redox and ESR properties of FA and/or FB, which indicates that in a minority of particles the terminal iron-sulfur protein remains attached to the reaction center core; (v) the ultrafiltered reaction center is severely deficient in all of the low molecular-weight polypeptides, particularly the 19-kDa, 18-kDa and 12-kDa polypeptides relative to the 64-kDa polypeptide(s); (vi) the stabilized particle contains 5.8 mol labile sulfide per mol photoactive P-700, reflecting largely the iron-sulfur content of Fx, but also residual FA and FB, on the reaction center; and (vii) the apoproteins of FA and FB are physically removed from the reaction center particle as indicated by the presence of protein-bound zero-valence sulfur in the YM-100 filtrate. These results are interpreted in terms of a model for Photosystem I in which FA and FB are located on a low-molecular-weight polypeptide and FX is depicted as a [2Fe-2S] cluster shared between the two high-molecular-weight polypeptides Photosystem I-A1 and Photosystem I-A2.

Original languageEnglish (US)
Pages (from-to)149-160
Number of pages12
JournalBBA - Bioenergetics
Volume893
Issue number2
DOIs
StatePublished - Sep 10 1987

Fingerprint

Photosystem I Protein Complex
Peptides
Sulfur
Molecular Weight
Molecular weight
Electrons
Membranes
Kinetics
Iron
Iron-Sulfur Proteins
Multiprotein Complexes
Apoproteins
chlorophyll P 700
Ultrafiltration
Sulfides
varespladib methyl
Genetic Recombination
Dilution
Oxidation-Reduction
Paramagnetic resonance

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry
  • Cell Biology

Cite this

@article{d4e7f6e3647340d8a7d2b9b11a0c6bef,
title = "Photosystem I charge separation in the absence of center A and B. III. Biochemical characterization of a reaction center particle containing P-700 and FX",
abstract = "The Photosystem I reaction center is a membrane-bound, multiprotein complex containing a primary electron donor (P-700), a primary electron acceptor (A0), an intermediate electron acceptor (A1) and three membrane-bound iron-sulfur centers (FX, FB, and FA). We reported in part I of this series (Golbeck, J.H. and Cornelius, J.M. (1986) Biochim. Biophys. Acta 849, 16-24) that in the presence of 1{\%} lithium dodecyl sulfate (LDS), the reaction center becomes dissociated, resulting in charge separation and recombination between P-700 and FX without the need for prereduction of FA and FB. In this paper, we report (i) the LDS-induced onset of the 1.2-ms 'fast' phase of the P-700 absorption transient is time-dependent, attaining a maximum 3:1 ratio of 'fast' to 'slow' kinetic phases; (ii) the 'fast' kinetic phase, corresponding to the P-700+ FX- backreaction, is stabilized indefinitely by dilution of the LDS-treated particle followed by ultrafiltration over a YM-100 membrane; (iii) without stabilization, the P-700+ FX- reaction deteriorates, leading to the rise of the long-lived P-700 triplet formed from the P-700+AO- backreaction; (iv) the 'slow' kinetic phase correlates with the redox and ESR properties of FA and/or FB, which indicates that in a minority of particles the terminal iron-sulfur protein remains attached to the reaction center core; (v) the ultrafiltered reaction center is severely deficient in all of the low molecular-weight polypeptides, particularly the 19-kDa, 18-kDa and 12-kDa polypeptides relative to the 64-kDa polypeptide(s); (vi) the stabilized particle contains 5.8 mol labile sulfide per mol photoactive P-700, reflecting largely the iron-sulfur content of Fx, but also residual FA and FB, on the reaction center; and (vii) the apoproteins of FA and FB are physically removed from the reaction center particle as indicated by the presence of protein-bound zero-valence sulfur in the YM-100 filtrate. These results are interpreted in terms of a model for Photosystem I in which FA and FB are located on a low-molecular-weight polypeptide and FX is depicted as a [2Fe-2S] cluster shared between the two high-molecular-weight polypeptides Photosystem I-A1 and Photosystem I-A2.",
author = "Golbeck, {John H.} and Parrett, {Kevin G.} and McDermott, {Ann E.}",
year = "1987",
month = "9",
day = "10",
doi = "10.1016/0005-2728(87)90034-X",
language = "English (US)",
volume = "893",
pages = "149--160",
journal = "Biochimica et Biophysica Acta - Bioenergetics",
issn = "0005-2728",
publisher = "Elsevier",
number = "2",

}

Photosystem I charge separation in the absence of center A and B. III. Biochemical characterization of a reaction center particle containing P-700 and FX . / Golbeck, John H.; Parrett, Kevin G.; McDermott, Ann E.

In: BBA - Bioenergetics, Vol. 893, No. 2, 10.09.1987, p. 149-160.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Photosystem I charge separation in the absence of center A and B. III. Biochemical characterization of a reaction center particle containing P-700 and FX

AU - Golbeck, John H.

AU - Parrett, Kevin G.

AU - McDermott, Ann E.

PY - 1987/9/10

Y1 - 1987/9/10

N2 - The Photosystem I reaction center is a membrane-bound, multiprotein complex containing a primary electron donor (P-700), a primary electron acceptor (A0), an intermediate electron acceptor (A1) and three membrane-bound iron-sulfur centers (FX, FB, and FA). We reported in part I of this series (Golbeck, J.H. and Cornelius, J.M. (1986) Biochim. Biophys. Acta 849, 16-24) that in the presence of 1% lithium dodecyl sulfate (LDS), the reaction center becomes dissociated, resulting in charge separation and recombination between P-700 and FX without the need for prereduction of FA and FB. In this paper, we report (i) the LDS-induced onset of the 1.2-ms 'fast' phase of the P-700 absorption transient is time-dependent, attaining a maximum 3:1 ratio of 'fast' to 'slow' kinetic phases; (ii) the 'fast' kinetic phase, corresponding to the P-700+ FX- backreaction, is stabilized indefinitely by dilution of the LDS-treated particle followed by ultrafiltration over a YM-100 membrane; (iii) without stabilization, the P-700+ FX- reaction deteriorates, leading to the rise of the long-lived P-700 triplet formed from the P-700+AO- backreaction; (iv) the 'slow' kinetic phase correlates with the redox and ESR properties of FA and/or FB, which indicates that in a minority of particles the terminal iron-sulfur protein remains attached to the reaction center core; (v) the ultrafiltered reaction center is severely deficient in all of the low molecular-weight polypeptides, particularly the 19-kDa, 18-kDa and 12-kDa polypeptides relative to the 64-kDa polypeptide(s); (vi) the stabilized particle contains 5.8 mol labile sulfide per mol photoactive P-700, reflecting largely the iron-sulfur content of Fx, but also residual FA and FB, on the reaction center; and (vii) the apoproteins of FA and FB are physically removed from the reaction center particle as indicated by the presence of protein-bound zero-valence sulfur in the YM-100 filtrate. These results are interpreted in terms of a model for Photosystem I in which FA and FB are located on a low-molecular-weight polypeptide and FX is depicted as a [2Fe-2S] cluster shared between the two high-molecular-weight polypeptides Photosystem I-A1 and Photosystem I-A2.

AB - The Photosystem I reaction center is a membrane-bound, multiprotein complex containing a primary electron donor (P-700), a primary electron acceptor (A0), an intermediate electron acceptor (A1) and three membrane-bound iron-sulfur centers (FX, FB, and FA). We reported in part I of this series (Golbeck, J.H. and Cornelius, J.M. (1986) Biochim. Biophys. Acta 849, 16-24) that in the presence of 1% lithium dodecyl sulfate (LDS), the reaction center becomes dissociated, resulting in charge separation and recombination between P-700 and FX without the need for prereduction of FA and FB. In this paper, we report (i) the LDS-induced onset of the 1.2-ms 'fast' phase of the P-700 absorption transient is time-dependent, attaining a maximum 3:1 ratio of 'fast' to 'slow' kinetic phases; (ii) the 'fast' kinetic phase, corresponding to the P-700+ FX- backreaction, is stabilized indefinitely by dilution of the LDS-treated particle followed by ultrafiltration over a YM-100 membrane; (iii) without stabilization, the P-700+ FX- reaction deteriorates, leading to the rise of the long-lived P-700 triplet formed from the P-700+AO- backreaction; (iv) the 'slow' kinetic phase correlates with the redox and ESR properties of FA and/or FB, which indicates that in a minority of particles the terminal iron-sulfur protein remains attached to the reaction center core; (v) the ultrafiltered reaction center is severely deficient in all of the low molecular-weight polypeptides, particularly the 19-kDa, 18-kDa and 12-kDa polypeptides relative to the 64-kDa polypeptide(s); (vi) the stabilized particle contains 5.8 mol labile sulfide per mol photoactive P-700, reflecting largely the iron-sulfur content of Fx, but also residual FA and FB, on the reaction center; and (vii) the apoproteins of FA and FB are physically removed from the reaction center particle as indicated by the presence of protein-bound zero-valence sulfur in the YM-100 filtrate. These results are interpreted in terms of a model for Photosystem I in which FA and FB are located on a low-molecular-weight polypeptide and FX is depicted as a [2Fe-2S] cluster shared between the two high-molecular-weight polypeptides Photosystem I-A1 and Photosystem I-A2.

UR - http://www.scopus.com/inward/record.url?scp=0001615353&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001615353&partnerID=8YFLogxK

U2 - 10.1016/0005-2728(87)90034-X

DO - 10.1016/0005-2728(87)90034-X

M3 - Article

AN - SCOPUS:0001615353

VL - 893

SP - 149

EP - 160

JO - Biochimica et Biophysica Acta - Bioenergetics

JF - Biochimica et Biophysica Acta - Bioenergetics

SN - 0005-2728

IS - 2

ER -