+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Comparison of alpha helix orientation in the chromatophore quantasome and reaction center of rhodopseudomonas viridis by circular dichroism and polarized ir spectroscopy



Comparison of alpha helix orientation in the chromatophore quantasome and reaction center of rhodopseudomonas viridis by circular dichroism and polarized ir spectroscopy



Biochimica et Biophysica Acta 809(2): 271-276



A comparison of the protein structure in chromatophores, quantasomes and reaction centreers of Rhodopseudomonas viridis is made by investigating ultraviolet circular dichroism and polarized infrared spectra of the intact chromatophore membrane, the isolated quantasome and the reaction centre reconstituted into phosphatidyl choline vesicles. A quantasome (photoreceptor unit) is made of a reaction centre surrounded by a ring of antenna complexes. Conformational analysis of the circular dichroism data indicates that intact chromatophores and quantasomes contain more .alpha.-helical structure (57%) than reaction centres (47%). Infrared dichroism data show that .alpha.-helical segments are on the average closer to the membrane normal in quantasomes (.vphi.alpha. = 28.degree.) than in reaction centres (.vphi.alpha. = 38.degree. C). This suggests a higher content of .alpha.-helices and a better orientation of transmembrane .alpha.-helical rods in the antennae surrounding the reaction centre. Our data are discussed in view of the results previously obtained by infrared dichroism of reaction centre films of Rps. sphaeroides (Nabedryk, E., Tiede, D.M., Dutton. P.L. and Breton, J. (1984) in Advances in Photosynthesis Research (Sybesma, C., ed.), Vol. II. pp. 177-180, Martinus Nijhoff/Dr. W. Junk Publishers, Dordrecht, The Netherlands) and by X-rays of reaction centre crystals of Rps. viridis (Deisenhofer, J., Epp, O., Miki. K., Huber, R. and Michel, H. (1984) J. Mol. Biol. 180, 385-398). Our results also imply that the secondary structure and orientation of the protein is comparable in bacteriochlorophyll a- and bacteriochlorophyll b-containing reaction centres. Furthermore, our data on the orientation of the .alpha.-helices in the reaction centre of Rps. viridis imply that the C-2 symmetry axis observed in the model derived from X-ray crystallography is oriented in vivo along the normal to the membrane plane.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 005004982

Download citation: RISBibTeXText


Related references

Orientation of the chromophores in the reaction center of rhodopseudomonas viridis comparison of low temperature linear dichroism spectra with a model derived from x ray crystallography. Biochimica et Biophysica Acta 810(2): 235-245, 1985

Circular dichroism of the 1300-nm band of oxidized reaction centers from Rhodopseudomonas viridis. Biochemistry (American Chemical Society) 24: 95-9, 1985

Circular dichroism of the 1300 nanometer band of oxidized reaction centers from rhodopseudomonas viridis. Biochemistry 24(17): 4495-4499, 1985

Asymmetry of reaction center particles and their orientation in chromatophore membranes a linear dichroism study 2. orientation of reaction centers in photosynthetic membranes. Studia Biophysica 82(1): 9-16, 1981

The orientations of reaction center transition moments in the chromatophore membrane of rhodopseudomonas sphaeroides based on new linear dichroism and photo selection measurements. Biochimica et Biophysica Acta 546(2): 189-206, 1979

Arrangement and interaction of pigment molecules in reaction centers of Rhodopseudomonas viridis. Photodichroism and circular dichroism of reaction centers at 100 k. Biochimica et Biophysica Acta 545(2): 296-308, 1979

Orientation of reaction center and antenna chromophores in the photosynthetic membrane of Rhodopseudomonas viridis. Biochimica et Biophysica Acta 545(2): 249-264, 1979

Protein prosthetic group interactions in bacterial reaction centers resonance raman spectroscopy of the reaction center of rhodopseudomonas viridis. Biochimica et Biophysica Acta 977(1): 10-18, 1989

The structure of tri-proline in water probed by polarized Raman, Fourier transform infrared, vibrational circular dichroism, and electric ultraviolet circular dichroism spectroscopy. Biopolymers 71(5): 558-568, 2003

Conformational analysis of myo toxin alpha muscle degenerating toxin of prairie rattlesnake crotalus viridis viridis venom predictions from amino acid sequence circular dichroism and raman spectroscopy. Journal of Biological Chemistry 254(18): 8922-8926, 1979

A theoretical examination of the electronic structure and spectroscopy of the photosynthetic reaction center from rhodopseudomonas viridis. Journal of the American Chemical Society 113(22): 8210-8215, 1991

Asymmetry of reaction center particles and their orientation in chromatophore membranes a linear dichroism study 1. asymmetry of shape. Studia Biophysica 80(3): 193-200, 1980

Orientation dependence of the epr signal from the reduced iron quinone complex in a single crystal of the reaction center protein from rhodopseudomonas viridis. Febs Letters 243(1): 1-4, 1989