Abstract：
:Dimers of bacteriochlorophyll a (Bchla) with optical absorption maximum at 853 nm and a nonconservative circular dichroism spectrum are formed in a solution of formamide/water that contains micelles of Triton X-100. The apparent equilibrium constant and the corresponding Gibbs energy change for the Bchl self-organization are 4.9 x 10(6) M(-1) and -9.2 kcal/mol, respectively. The experimental absorption and circular dichroism spectra of the in vitro Bchl dimer (termed Bchl-853) are similar to the spectra of the bacterial light-harvesting complex B850 and the primary electron donor P-860 and probably point to a common structural motif. Indeed, simulation of the dimers' spectra (optical absorption and circular dichroism), achieved by using an extended version of the exciton theory, suggests the same geometry as recently elucidated for P-860 by x-ray diffraction crystallography. The proposed geometry is predicted to have the minimum energy in the gas phase. In conclusion, the spectral properties of the bathochromically shifted forms of Bchla are likely a result of strong dipolar interactions in self-organized structures of Bchls.
journal_name
Proc Natl Acad Sci U S Aauthors
Scherz A,Rosenbach-Belkin Vdoi
10.1073/pnas.86.5.1505keywords:
subject
Has Abstractpub_date
1989-03-01 00:00:00pages
1505-9issue
5eissn
0027-8424issn
1091-6490journal_volume
86pub_type
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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doi：10.1073/pnas.182157199
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
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更新日期：1990-05-01 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：2012-09-18 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：2005-03-08 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：2013-08-20 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：2012-07-31 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：1985-12-01 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：1999-09-28 00:00:00
