Following [FeFe] Hydrogenase Active Site Intermediates by Time-Resolved Mid-IR Spectroscopy

详细信息    查看全文

• 作者：Mohammad Mirmohades ; Agnieszka Adamska-Venkatesh ; Constanze Sommer ; Edward Reijerse ; Reiner Lomoth ; Wolfgang Lubitz ; Leif Hammarström
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2016
• 出版时间：August 18, 2016
• 年：2016
• 卷：7
• 期：16
• 页码：3290-3293
• 全文大小：278K
• 年卷期：0
• ISSN：1948-7185

文摘

Time-resolved nanosecond mid-infrared spectroscopy is for the first time employed to study the [FeFe] hydrogenase from Chlamydomonas reinhardtii and to investigate relevant intermediates of the enzyme active site. An actinic 355 nm, 10 ns laser flash triggered photodissociation of a carbonyl group from the CO-inhibited state H_ox-CO to form the state H_ox, which is an intermediate of the catalytic proton reduction cycle. Time-resolved infrared spectroscopy allowed us to directly follow the subsequent rebinding of the carbonyl, re-forming H_ox-CO, and determine the reaction half-life to be t_1/2 ≈ 13 ± 5 ms at room temperature. This gives direct information on the dynamics of CO inhibition of the enzyme.