ENDOR studies of the primary donor cation radical in mutant reaction centers of Rhodobacter sphaeroides with altered hydrogen-bond interactions

J. Rautter, F. Lendzian, C. Schulz, A. Fetsch, M. Kuhn, X. Lin, J. C. Williams, James Paul Allen, W. Lubitz

Research output: Contribution to journalArticle

92 Citations (Scopus)

Abstract

The electronic structure of the cation radical of the primary electron donor was investigated in genetically modified reaction centers of Rhodobacter sphaeroides. The site-directed mutations were designed to add or remove hydrogen bonds between the conjugated carbonyl groups of the primary donor, a bacteriochlorophyll dimer, and histidine residues of the protein and were introduced at the symmetry-related sites L168 His→Phe, HF(L168), and M197 Phe→His, FH(M197), near the 2-acetyl groups of the dimer and at sites M160 Leu→His, LH(M160), and L131 Leu→His, LH(L131), in the vicinity of the 9-keto carbonyls of the dimer. The single mutants and a complete set of double mutants were studied using EPR, ENDOR, and TRIPLE resonance spectroscopy. The changes in the hydrogen bond situation of the primary donor were accompanied by changes in the dimer oxidation midpoint potential, ranging from 410 to 710 mV in the investigated mutants [Lin, X., Murchison, H. A., Nagarajan, V., Parson, W. W., Williams, J. C., & Allen, J. P. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 10265-10269]. It was found that the addition or removal of a hydrogen bond causes large shifts of the spin density between the two halves of the dimer. Measurements on double mutants showed that the unpaired electron can be gradually shifted from a localization on the L-half of the dimer to a localization on the M-half, depending on the hydrogen bond situation. As a control, the effects of the different hydrogen bonds on P•+ in the mutant HL(M202), which contains a BChlL-BPheM heterodimer as the primary donor with localized spin on the BChl aL [Bylina, E. J., & Youvan, D. C. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7226-7230; Schenck, C. C., Gaul, D., Steffen M., Boxer S. G., McDowell L., Kirmaier C., & Holten D. (1990) in Reaction Centers of Photosynthetic Bacteria (Michel-Beyerle M. E., Ed.) pp 229-238, Springer, Berlin] were studied. In this mutant only small local changes of the spin densities (≤10%) in the vicinity of the hydrogen bonds were observed. The effects of the introduced hydrogen bonds on the spin density distribution of the dimer in the mutants are discussed in terms of different orbital energies of the two BChl a moieties which are directly influenced by hydrogen bond formation. The observed changes of the spin density distribution for the double mutants are additive with respect to the single mutations. This indicates that no major structural changes occur due to the replacement of the amino acid residues. The asymmetric spin density distributions of P•+ were compared with electron transfer rates. A pronounced influence was observed on the P•+ reduction rate by cytochrome C2.

Original languageEnglish
Pages (from-to)8130-8143
Number of pages14
JournalBiochemistry
Volume34
Issue number25
Publication statusPublished - 1995

Fingerprint

Rhodobacter sphaeroides
Electron Spin Resonance Spectroscopy
Cations
Hydrogen
Dimers
Hydrogen bonds
Electrons
Cytochromes c2
Photosynthetic Reaction Center Complex Proteins
Bacteriochlorophylls
Mutation
Berlin
Histidine
Electronic structure
Paramagnetic resonance
Spectrum Analysis
Bacteria
Spectroscopy
Amino Acids
Oxidation

ASJC Scopus subject areas

  • Biochemistry

Cite this

Rautter, J., Lendzian, F., Schulz, C., Fetsch, A., Kuhn, M., Lin, X., ... Lubitz, W. (1995). ENDOR studies of the primary donor cation radical in mutant reaction centers of Rhodobacter sphaeroides with altered hydrogen-bond interactions. Biochemistry, 34(25), 8130-8143.

ENDOR studies of the primary donor cation radical in mutant reaction centers of Rhodobacter sphaeroides with altered hydrogen-bond interactions. / Rautter, J.; Lendzian, F.; Schulz, C.; Fetsch, A.; Kuhn, M.; Lin, X.; Williams, J. C.; Allen, James Paul; Lubitz, W.

In: Biochemistry, Vol. 34, No. 25, 1995, p. 8130-8143.

Research output: Contribution to journalArticle

Rautter, J, Lendzian, F, Schulz, C, Fetsch, A, Kuhn, M, Lin, X, Williams, JC, Allen, JP & Lubitz, W 1995, 'ENDOR studies of the primary donor cation radical in mutant reaction centers of Rhodobacter sphaeroides with altered hydrogen-bond interactions', Biochemistry, vol. 34, no. 25, pp. 8130-8143.
Rautter, J. ; Lendzian, F. ; Schulz, C. ; Fetsch, A. ; Kuhn, M. ; Lin, X. ; Williams, J. C. ; Allen, James Paul ; Lubitz, W. / ENDOR studies of the primary donor cation radical in mutant reaction centers of Rhodobacter sphaeroides with altered hydrogen-bond interactions. In: Biochemistry. 1995 ; Vol. 34, No. 25. pp. 8130-8143.
@article{1ca238938b3540e4a68751b48cfdb7e7,
title = "ENDOR studies of the primary donor cation radical in mutant reaction centers of Rhodobacter sphaeroides with altered hydrogen-bond interactions",
abstract = "The electronic structure of the cation radical of the primary electron donor was investigated in genetically modified reaction centers of Rhodobacter sphaeroides. The site-directed mutations were designed to add or remove hydrogen bonds between the conjugated carbonyl groups of the primary donor, a bacteriochlorophyll dimer, and histidine residues of the protein and were introduced at the symmetry-related sites L168 His→Phe, HF(L168), and M197 Phe→His, FH(M197), near the 2-acetyl groups of the dimer and at sites M160 Leu→His, LH(M160), and L131 Leu→His, LH(L131), in the vicinity of the 9-keto carbonyls of the dimer. The single mutants and a complete set of double mutants were studied using EPR, ENDOR, and TRIPLE resonance spectroscopy. The changes in the hydrogen bond situation of the primary donor were accompanied by changes in the dimer oxidation midpoint potential, ranging from 410 to 710 mV in the investigated mutants [Lin, X., Murchison, H. A., Nagarajan, V., Parson, W. W., Williams, J. C., & Allen, J. P. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 10265-10269]. It was found that the addition or removal of a hydrogen bond causes large shifts of the spin density between the two halves of the dimer. Measurements on double mutants showed that the unpaired electron can be gradually shifted from a localization on the L-half of the dimer to a localization on the M-half, depending on the hydrogen bond situation. As a control, the effects of the different hydrogen bonds on P•+ in the mutant HL(M202), which contains a BChlL-BPheM heterodimer as the primary donor with localized spin on the BChl aL [Bylina, E. J., & Youvan, D. C. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7226-7230; Schenck, C. C., Gaul, D., Steffen M., Boxer S. G., McDowell L., Kirmaier C., & Holten D. (1990) in Reaction Centers of Photosynthetic Bacteria (Michel-Beyerle M. E., Ed.) pp 229-238, Springer, Berlin] were studied. In this mutant only small local changes of the spin densities (≤10{\%}) in the vicinity of the hydrogen bonds were observed. The effects of the introduced hydrogen bonds on the spin density distribution of the dimer in the mutants are discussed in terms of different orbital energies of the two BChl a moieties which are directly influenced by hydrogen bond formation. The observed changes of the spin density distribution for the double mutants are additive with respect to the single mutations. This indicates that no major structural changes occur due to the replacement of the amino acid residues. The asymmetric spin density distributions of P•+ were compared with electron transfer rates. A pronounced influence was observed on the P•+ reduction rate by cytochrome C2.",
author = "J. Rautter and F. Lendzian and C. Schulz and A. Fetsch and M. Kuhn and X. Lin and Williams, {J. C.} and Allen, {James Paul} and W. Lubitz",
year = "1995",
language = "English",
volume = "34",
pages = "8130--8143",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "25",

}

TY - JOUR

T1 - ENDOR studies of the primary donor cation radical in mutant reaction centers of Rhodobacter sphaeroides with altered hydrogen-bond interactions

AU - Rautter, J.

AU - Lendzian, F.

AU - Schulz, C.

AU - Fetsch, A.

AU - Kuhn, M.

AU - Lin, X.

AU - Williams, J. C.

AU - Allen, James Paul

AU - Lubitz, W.

PY - 1995

Y1 - 1995

N2 - The electronic structure of the cation radical of the primary electron donor was investigated in genetically modified reaction centers of Rhodobacter sphaeroides. The site-directed mutations were designed to add or remove hydrogen bonds between the conjugated carbonyl groups of the primary donor, a bacteriochlorophyll dimer, and histidine residues of the protein and were introduced at the symmetry-related sites L168 His→Phe, HF(L168), and M197 Phe→His, FH(M197), near the 2-acetyl groups of the dimer and at sites M160 Leu→His, LH(M160), and L131 Leu→His, LH(L131), in the vicinity of the 9-keto carbonyls of the dimer. The single mutants and a complete set of double mutants were studied using EPR, ENDOR, and TRIPLE resonance spectroscopy. The changes in the hydrogen bond situation of the primary donor were accompanied by changes in the dimer oxidation midpoint potential, ranging from 410 to 710 mV in the investigated mutants [Lin, X., Murchison, H. A., Nagarajan, V., Parson, W. W., Williams, J. C., & Allen, J. P. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 10265-10269]. It was found that the addition or removal of a hydrogen bond causes large shifts of the spin density between the two halves of the dimer. Measurements on double mutants showed that the unpaired electron can be gradually shifted from a localization on the L-half of the dimer to a localization on the M-half, depending on the hydrogen bond situation. As a control, the effects of the different hydrogen bonds on P•+ in the mutant HL(M202), which contains a BChlL-BPheM heterodimer as the primary donor with localized spin on the BChl aL [Bylina, E. J., & Youvan, D. C. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7226-7230; Schenck, C. C., Gaul, D., Steffen M., Boxer S. G., McDowell L., Kirmaier C., & Holten D. (1990) in Reaction Centers of Photosynthetic Bacteria (Michel-Beyerle M. E., Ed.) pp 229-238, Springer, Berlin] were studied. In this mutant only small local changes of the spin densities (≤10%) in the vicinity of the hydrogen bonds were observed. The effects of the introduced hydrogen bonds on the spin density distribution of the dimer in the mutants are discussed in terms of different orbital energies of the two BChl a moieties which are directly influenced by hydrogen bond formation. The observed changes of the spin density distribution for the double mutants are additive with respect to the single mutations. This indicates that no major structural changes occur due to the replacement of the amino acid residues. The asymmetric spin density distributions of P•+ were compared with electron transfer rates. A pronounced influence was observed on the P•+ reduction rate by cytochrome C2.

AB - The electronic structure of the cation radical of the primary electron donor was investigated in genetically modified reaction centers of Rhodobacter sphaeroides. The site-directed mutations were designed to add or remove hydrogen bonds between the conjugated carbonyl groups of the primary donor, a bacteriochlorophyll dimer, and histidine residues of the protein and were introduced at the symmetry-related sites L168 His→Phe, HF(L168), and M197 Phe→His, FH(M197), near the 2-acetyl groups of the dimer and at sites M160 Leu→His, LH(M160), and L131 Leu→His, LH(L131), in the vicinity of the 9-keto carbonyls of the dimer. The single mutants and a complete set of double mutants were studied using EPR, ENDOR, and TRIPLE resonance spectroscopy. The changes in the hydrogen bond situation of the primary donor were accompanied by changes in the dimer oxidation midpoint potential, ranging from 410 to 710 mV in the investigated mutants [Lin, X., Murchison, H. A., Nagarajan, V., Parson, W. W., Williams, J. C., & Allen, J. P. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 10265-10269]. It was found that the addition or removal of a hydrogen bond causes large shifts of the spin density between the two halves of the dimer. Measurements on double mutants showed that the unpaired electron can be gradually shifted from a localization on the L-half of the dimer to a localization on the M-half, depending on the hydrogen bond situation. As a control, the effects of the different hydrogen bonds on P•+ in the mutant HL(M202), which contains a BChlL-BPheM heterodimer as the primary donor with localized spin on the BChl aL [Bylina, E. J., & Youvan, D. C. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7226-7230; Schenck, C. C., Gaul, D., Steffen M., Boxer S. G., McDowell L., Kirmaier C., & Holten D. (1990) in Reaction Centers of Photosynthetic Bacteria (Michel-Beyerle M. E., Ed.) pp 229-238, Springer, Berlin] were studied. In this mutant only small local changes of the spin densities (≤10%) in the vicinity of the hydrogen bonds were observed. The effects of the introduced hydrogen bonds on the spin density distribution of the dimer in the mutants are discussed in terms of different orbital energies of the two BChl a moieties which are directly influenced by hydrogen bond formation. The observed changes of the spin density distribution for the double mutants are additive with respect to the single mutations. This indicates that no major structural changes occur due to the replacement of the amino acid residues. The asymmetric spin density distributions of P•+ were compared with electron transfer rates. A pronounced influence was observed on the P•+ reduction rate by cytochrome C2.

UR - http://www.scopus.com/inward/record.url?scp=0029012645&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029012645&partnerID=8YFLogxK

M3 - Article

VL - 34

SP - 8130

EP - 8143

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 25

ER -