| Abstract
| - The CO stretch mode of various substrate complexes of cytochromeP-450cam-CO wasmeasured using FT infrared spectroscopy. At room temperature mostof the complexes show a single,but often asymmetric infrared band. The representative wavenumberof this band for the various complexesincreases when the high-spin content, induced by the substrates in theoxidized protein, decreases.Additionally, the increase of the CO stretch wavenumber (1939 to1956 cm-1) correlates with thedecreaseof the Soret band wavenumber (22 440 to 22 373cm-1). It is suggested that the polarityof the hemepocket is modulated by the substrates due to changed accessibility ofthe heme environment for watermolecules. The increased water content compensates positiveelectrostatic potentials near the CO ligand,which results in loosening the contact of CO to the Ihelix.
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