The influence of transition metal binding on the charge storage ability of native bacterial reaction centers (BRCs) was investigated. Binding of manganous ions uniquely prevented the light-induced conformational changes that would yield to long lifetimes of the charge separated state and the drop of the redox potential of the primary electron donor (P). The lifetimes of the stable charge pair in the terminal conformations were shortened by 50-fold and 7-fold upon manganous and cupric ion binding, respectively. Nickel and zinc binding had only marginal effects. Binding of manganese not only prevented the drop of the potential of P/P⁺ but also elevated it by up to 117 mV depending on where the metal was binding. With variable conditions, facilitating either manganese binding or light-induced structural changes a controlled tuning of the potential of P/P⁺ in multiple steps was demonstrated in a range of ~200 mV without the need of a mutation or synthesis. Under the selected conditions, manganese binding was achieved without its photochemical oxidation thus, the energized but still native BRCs can be utilized in photochemistry that is not reachable with regular BRCs. A 42 Å long hydrophobic tunnel was identified that became obstructed upon manganese binding and its likely role is to deliver protons from the hydrophobic core to the surface during conformational changes.

研究了过渡金属结合对天然细菌反应中心（BRC）电荷存储能力的影响。锰离子的结合独特地阻止了光诱导的构象变化，这种变化会导致电荷分离态的长寿命和一次电子供体（P）的氧化还原电势下降。锰和铜离子结合后，末端构象中稳定电荷对的寿命分别缩短了50倍和7倍。镍和锌的结合仅具有边际效应。结合锰不仅可以防止P / P ⁺电位下降但也可以将其升高至117 mV，具体取决于金属的结合位置。在可变条件下，通过促进锰结合或光诱导的结构变化，证明了在约200 mV的范围内无需突变或合成即可在多个步骤中控制P / P ⁺电位的调节。在选定的条件下，实现了锰结合而没有光化学氧化，因此，通电但仍然天然的BRC可以用于常规BRC无法达到的光化学中。鉴定出一条42Å长的疏水通道，该通道因锰结合而受阻，其可能的作用是在构象变化期间将质子从疏水核传递到表面。