Trapping the P+BL− Initial Intermediate State of Charge Separation in Photosynthetic Reaction Centers from Rhodobacter capsulatus†

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• 作者：Brett Carter^‡ ; ; Steven G. Boxer^‡ ; ; Dewey Holten^§ ; ; Christine Kirmaier*^§ ;
• 刊名：Biochemistry
• 出版年：2009
• 出版时间：March 31, 2009
• 年：2009
• 卷：48
• 期：12
• 页码：2571-2573
• 全文大小：176K
• 年卷期：v.48,no.12(March 31, 2009)
• ISSN：1520-4995

文摘

The short-lived (<1 ps) initial intermediate state P⁺B_L⁻ in the photoinduced charge separation process of the bacterial photosynthetic reaction center has been trapped in two D_LL-based Rhodobacter capsulatus mutants that have Tyr at position M208 and lack the bacteriopheophytin electron acceptor H_L. Transient state P⁺B_L⁻ is characterized by a 1017 nm bacteriochlorophyll anion absorption band and decays by charge recombination with a lifetime of several hundred picoseconds at 295 K. P⁺B_L⁻ is not observed in an otherwise identical mutant that has Phe at M208, which appears to make the state thermodynamically inaccessible from the excited primary electron donor P*.