Skip to main content
Log in

On the structure of bacteriochlorophyll molecular aggregates in the chlorosomes of green bacteria. A molecular modelling study

  • Group 5: Chlorosomes and Pigments
  • Regular Papers
  • Published:
Photosynthesis Research Aims and scope Submit manuscript

Abstract

The supramolecular structure of methyl (31 R)-BChlided aggregation has been explored by molecular modelling in order to elucidate the unusual structure of the BChl rods in the chlorosomal antennae of green bacteria. The aggregate construction progressed from a BChlide monomer in 5c coordination which was stepwise combined to form trimeric, pentameric and decameric chlorin stacks, all incorporating Mg····O-H as a basic interaction element which links two chlorins between the 31-hydroxyl oxygen and the Mg. Up to the level of the trimer, the structures were optimized by both a semiempirical quantum chemical method (PM3) and a force field method, while larger structures were only modelled by the force field (MM+). Strong interactions were found by extended stacking of chlorins which are in van der Waals contact. Extended hydrogen bonding networks upon stack pairing brought about by OH····O=C bonds (bond length ca. 2.2Å, angle 139–153°) between appropriately situated chlorin pairs and by electrostatic interactions lead to very large energy stabilizations. The structural features of a modelled 40mer BChl aggregate are in full accord with all spectroscopic and low-resolution structural information on the in-vitro and chlorosomal BChl aggregates. Most important, from the rotation angle between stacks of ca. 16° and the stack-to-stack distance of 7.6 Å a tubular structure can be extrapolated to form on further extension of the aggregate. It has a predicted diameter of about 5.4 nm (Mg-Mg distance), i.e. very similar to that found for the rod elements in the chlorosomes ofChloroflexus.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

BChl:

bacteriochlorophyll

BChlide:

bacteriochlorophyllide

References

  • Abraham RJ and Smith KM (1983) NMR spectra of porphyrins. 21. Applications of the ring-current model to porphyrin and chlorophyll aggregation. J Am Chem Soc 105: 5734–5741

    Google Scholar 

  • Allinger NL (1977) Conformational analysis. 130. NM2. A hydrocarbon force field utilizing V1 and V2 torsional terms. J Am Chem Soc 99: 8127–8134

    Google Scholar 

  • Blankenship RE, Brune DC and Wittmershaus BP (1988) Chlorosome antennas in green photosynthetic bacteria. In: Stevens SE and Bryant DA (eds) Light-Energy Transduction in Photosynthesis: Higher Plants and Bacterial Models, pp 32–46. American Society of Plant Physiologists, Rockville, MD

    Google Scholar 

  • Brune DC, Nozawa T and Blankenship RE (1987) Antenna organization in green photosynthetic bacteria. 1. Oligomeric bacterichlorophyllc as a model for the 740nm absorbing bacteriochlorophyllc inChloroflexus aurantiacus chlorosomes. Biochemistry 26: 8644–8652

    Google Scholar 

  • Bystrova MI, Mal'gosheva IN and Krasnovskii AA (1979) Study of molecular mechanism of self-assembly of aggregated forms of bacteriochlorophyllc. Mol Biol 13: 440–451

    Google Scholar 

  • Chiefari J, Griebenow K, Griebenow N, Balaban TS, Holzwarth AR and Schaffner K (1995) Models for the pigment organization in the chlorosomes of photosynthetic bacteria-stereochemical control of in-vitro Bacteriochlorophyll-c s aggregation. Z Naturforsch (in press)

  • Chow H-C, Serlin R and Strouse CE (1975) The crystal and molecular structure and absolute configuration of ethyl chlorophyllidea dihydrate. A model for the different spectral forms of chlorophylla. J Am Chem Soc 97: 7230–7237

    Google Scholar 

  • Dearing A (1988) Computer-aided molecular modelling: Research study or research tool? J Comp Mol Design 2: 179–189

    Google Scholar 

  • Dewar MJ, Zoebich EG, Healy EF and Stewart JJP (1985) AM1: A new general purpose quantum mechanical molecular model. J Am Chem Soc 107: 3902–3909

    Google Scholar 

  • Fages F, Griebenow N, Griebenow K, Holzwarth AR and Schaffner K (1990) Characterization of light-harvesting pigments ofChloroflexus aurantiacus. Two new chlorophylls: Oleyl (octadec-9-enyl) and cetyl (hexadecanyl) bacteriochlorophyllides-c. J Chem Soc Perkin Trans I 1990: 2791–2797

    Google Scholar 

  • Feick RG and Fuller RC (1984) Topography of the photosynthetic apparatus ofChloroflexus aurantiacus. Biochemistry 23: 3693–3700

    Google Scholar 

  • Griebenow K and Holzwarth AR (1989) Pigment organization and energy transfer in green bacteria. 1. Isolation of native chlorosomes free of bound bacteriochlorophyll a fromChloroflexus aurantiacus by gel-electrophoretic filtration (GEF). Biochim Biophys Acta 973: 235–240

    Google Scholar 

  • Griebenow K, Holzwarth AR, vanMourik F and vanGrondelle R (1991) Pigment organization and energy transfer in green bacteria. 2. Circular and linear dichroism spectra of protein-containing and protein-free chlorosomes isolated fromChloroflexus aurantiacus strain OK-70-fl*. Biochim Biophys Acta 1058: 194–202

    Google Scholar 

  • Hildebrandt P, Griebenow K, Holzwarth AR and Schaffner K (1991) Resonance Raman spectroscopic evidence for the identity of the bacteriochlorophyllc organization in protein-free and protein-containing chlorosomes fromChloroflexus aurantiacus. Z Naturforsch 46C: 228–232

    Google Scholar 

  • Hildebrandt P, Tamiaki H, Holzwarth AR and Schaffner K (1994) Resonance Raman spectroscopic study of metallochlorin aggregates. Implications for the supramolecular structure of chlorosomal bacteriochlorophyll-c antennae of green bacteria. J Phys Chem 98: 2191–2197

    Google Scholar 

  • Holzwarth AR, Griebenow K and Schaffner K (1990) A photosynthetic antenna system which contains a protein-free chromophore aggregate. Z Naturforsch 45C: 203–206

    Google Scholar 

  • Holzwarth AR, Griebenow K and Schaffner K (1992) Chlorosomes, photosynthetic antennae with novel selforganized pigment structures. J Photochem Photobiol A 65: 61–71

    Google Scholar 

  • Hunter CA and Sander JKM (1990) The nature of ⧄-⧄ interactions. J Am Chem Soc 112: 5525–5534

    Google Scholar 

  • Jörgensen WL (1989) Free energy calculations: A breakthrough for modeling organic chemistry in solution. Acc Chem Res 24: 184–189

    Google Scholar 

  • Kratky C and Dunitz JD (1977) Ordered aggregation states of chlorophylla and some derivatives. J Mol Biol 113: 431–442

    Google Scholar 

  • Kratky C and Dunitz JD (1986) Comparison of the results of two independent analyses of the ethylchlorophyllidea dihydratecrys-tal structure. Acta Cryst 31B: 1586–1589

    Google Scholar 

  • Lutz M and VanBrakel G (1988) Ground-state molecular interactions of bacteriochlorophyllc in chlorosomes of green bacteria and in model systems: A resonance Raman study. In: Olson JM, Ormerod JG, Amesz J, Stackebrandt E and Truper HG (eds) Green Photosynthetic Bacteria, pp 23–34. Plenum Press, New York

    Google Scholar 

  • Mayo SL, Olafson BD and Goddard WAIII (1990) DREIDING: A generic force field for molecular simulations. J Phys Chem 94: 8897–8909

    Google Scholar 

  • Nozawa T, Suzuki M, Kanno S and Shirai S (1990) CP/MAS 13C-NMR studies on the structure of bacteriochlorophyllc in chlorosomes fromChloroflexus aurantiacus. Chem Lett 1990: 1805–1808

    Google Scholar 

  • Olson JM (1980) Chlorophyll organization in green photosynthetic bacteria. Biochim Biophys Acta 594: 33–51

    Google Scholar 

  • Olson JM and Pedersen JP (1988) Bacteriochlorophyllc aggregates in carbon tetrachloride as models for chlorophyll organization in green photosynthetic bacteria. In: Scheer H and Schneider S (eds) Photosynthetic Light-Harvesting Systems, pp 365–373. De Gruyter, Berlin

    Google Scholar 

  • Olson JM and Pedersen JP (1990) Bacteriochlorophyllc monomers, dimers, and higher aggregates in dichloromethane, chloroform, and carbon tetrachloride. Photosynth Res 25: 25–37

    Google Scholar 

  • Olson JM, Gerola PD, vanBrakel GH, Meiburg RF and Vasmel H (1985) Bacteriochlorophylla- andc-protein complexes from chlorosomes of green sulfur bacteria compared with bacteriochlorophyllc aggregates in CH2Cl2-hexane. In: Michel-Beyerle ME (ed) Antennas and Reaction Centers of Photosynthetic Bacteria, pp 67–73. Springer Ser Chem Phys, Vol 42. Springer, Berlin

    Google Scholar 

  • Olson JM, Pedersen JP, Causgrove TP, Brune DC and Blankenship RE (1990) Bacteriochlorophyllc monomers, dimers, and higher aggregates in dichloromethane and carbon tetrachloride. In: Baltscheffsky M (ed) Current Research in Photosynthesis, pp 37–40. Kluwer Academic Publishers, Dordrecht

    Google Scholar 

  • Smith KM, Goff DA, Fajer J and Barkigia KM (1983a) Isolation and characterization of two new bacteriochlorophyllsd bearing neopentyl substituents. J Am Chem Soc 105: 1674–1676

    Google Scholar 

  • Smith KM, Kehres LA and Fajer J (1983b) Aggregation of the bacteriochlorophyllsc, d, ande. Models for the antenna chlorophylls of green and brown photosynthetic bacteria. J Am Chem Soc 105: 1387–1389

    Google Scholar 

  • Staehelin LA, Golecki JR, Fuller RC and Drews G (1978) Visualization of supramolecular architecture of chlorosomes (Chlorobium type vesicles) in freeze-fractured cells ofChloroflexus aurantiacus. Arch Mikrobiol 119: 269–277

    Google Scholar 

  • Staehelin LA, Golecki JR and Drews G (1980) Supramolecular organization of chlorosomes (Chlorobium vesicles) and of their membrane attachment sites inChlorobium limicola. Biochim Biophys Acta 589: 30–45

    Google Scholar 

  • Stewart JJP (1990a) Semi-empirical molecular orbital methods. In: Lipkovitz K and Boyd DB (eds) Reviews of Computational Chemistry, pp 45–81. VCM Publishers, New York

    Google Scholar 

  • Stewart JJP (1990b) MOPAC: A semiempirical molecular orbital program. J Computer-Aided Mol Design 4: 1–103

    Google Scholar 

  • Strouse CE (1974) The crystal and molecular structure of ethyl chlorophyllidea. 2H2O and its relationship to the structure and aggreation of chlorophylla. Proc Natl Acad Sci USA 71: 325–328

    Google Scholar 

  • Tamiaki H, Holzwarth AR and Schaffner K (1992) A synthetic zinc chlorin aggregate as a model for the supramolecular antenna complexes in the chlorosomes of green bacteria. J Photochem Photobiol B 15: 355–360

    Google Scholar 

  • Tamiaki H, Holzwarth AR and Schaffner K (1994a) Dimerization of synthetic zinc aminochlorins in non-polar organic solvents. Photosynth Res 41: 245–251 (this issue)

    Google Scholar 

  • Tamiaki H, Takeuchi S, Tanikaga R, Balaban ST, Holzwarth AR and Schaffner K (1994b) Diastereoselective control of aggregation of 31-Epimeric zinc methyl bacteriopheophorbides-d in apolar solvents. Chem Lett 1994: 401–402

    Google Scholar 

  • Uehara K, Ozaki Y, Okada K and Olson JM (1991) FT-IR studies on the aggregation of bacteriochlorophyllc fromChlorobium limicola. Chem Lett 1991: 909–912

    Google Scholar 

  • VanDorssen RJ, Gerola PD, Olson JM and Amesz J (1986) Optical and structural properties of chlorosomes of the photosynthetic green sulfur bacteriumChlorobium limicola. Biochim Biophys Acta 848: 77–82

    Google Scholar 

  • Wechsler T, Suter F, Fuller RC and Zuber H (1985) The complete amino acid sequence of the bacteriochlorophyllc binding polypeptide from chlorosomes of the green photosynthetic bacteriumChloroflexus aurantiacus. FEBS Lett 181: 173–178

    Google Scholar 

  • Worcester DL, Michalski TJ and Katz JJ (1986) Small-angle neutron scattering studies of chlorophyll micelles: Models for bacterial antenna chlorophyll. Proc Natl Acad Sci USA 83: 3791–3795

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

Dedicated to J.J. Katz, pioneer in the study of chlorophyll aggregation.

Dedicated to J.J. Katz, pioneer in the study of chlorophyll aggregation.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Holzwarth, A.R., Schaffner, K. On the structure of bacteriochlorophyll molecular aggregates in the chlorosomes of green bacteria. A molecular modelling study. Photosynth Res 41, 225–233 (1994). https://doi.org/10.1007/BF02184163

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02184163

Key words

Navigation