Decay of the Transient CuB-CO Complex Is Accompanied by Formation of the Heme Fe-CO Complex of Cytochrome cbb3-CO at Ambient Temperature: Evidence from Time-Resolved Fouri
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- 作者：Stavros Stavrakis ; Konstantinos Koutsoupakis ; Eftychia Pinakoulaki ; Andrea Urbani ; Matti Saraste ; and Constantinos Varotsis
- 刊名：Journal of the American Chemical Society
- 出版年：2002
- 出版时间：April 17, 2002
- 年：2002
- 卷：124
- 期：15
- 页码：3814 - 3815
- 全文大小：41K
- 年卷期：v.124,no.15(April 17, 2002)
- ISSN：1520-5126
文摘
Time-resolved step-scan Fourier infrared spectroscopy has been used to study the CO-bound cbb3-type cytochrome c oxidase from Pseudomonas stutzeri at room temperature. We observe a single band in the FTIR spectrum at 1956 cm-1 (
-form). The time-resolved data indicate that upon photolysis, CO is transferred from heme b3 (
CO = 1956 cm-1) to CuB (CO = 2064 cm-1). The decay of the 2065 cm-1 peak (t1/2 = 120 ± 16 ms) and the development of the 1956 cm-1 peak (t1/2 = 144 ± 8 ms ) suggest that formation of the Fe-CO complex is concurrent with the decay of the CuB-CO complex. The intensity ratio of the Fe-CO/CuB-CO (2.15) remains constant for all data points, and thus we conclude that no fraction of CO escapes the binuclear center at 293 K.
-form). The time-resolved data indicate that upon photolysis, CO is transferred from heme b3 (CO = 1956 cm-1) to CuB (CO = 2064 cm-1). The decay of the 2065 cm-1 peak (t1/2 = 120 ± 16 ms) and the development of the 1956 cm-1 peak (t1/2 = 144 ± 8 ms ) suggest that formation of the Fe-CO complex is concurrent with the decay of the CuB-CO complex. The intensity ratio of the Fe-CO/CuB-CO (2.15) remains constant for all data points, and thus we conclude that no fraction of CO escapes the binuclear center at 293 K.