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Publication Citation: Cytochrome c at Model Membrane Surfaces: Exploration via Second Harmonic Generation - Circular Dichroism and Surface-Enhanced Resonance Raman Spectroscopy

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Author(s): T Petralli-Mallow; Anne L. Plant; M Lewis; J Hicks;
Title: Cytochrome c at Model Membrane Surfaces: Exploration via Second Harmonic Generation - Circular Dichroism and Surface-Enhanced Resonance Raman Spectroscopy
Published: July 11, 2000
Abstract: The novel nonlinear optical method second harmonic generation-circular dichroism (SHG-CD) has been used to follow the adsorption and redox properties of a peripheral membrane protein horse heart cytochrome c, adsorbed at several model membrane surfaces. SHG-CD response is shown to be effected by the oxidation state of the heme within surface-adsorbed cytochrome c, as is consistent with the sensitivity of SHG to the chirality of the heme. SHG-CD measurements show that adsorbed cytochrome c is reducible by ascorbate at alkanethiol surfaces, but not at a phospholipid/alkanethiol hybrid bilayer membranes (HBMs). The adsorption of cytochrome c at the model membrane surfaces was verified by surface plasmon resonance. Surface enhanced resonance Raman measurements show that cytochrome c adsorbed on a hybrid bilayer membrane retains the Fe-heme conformation associated with solution-phase cytochrome c and is reducible by applying potential to the supporting electrode. The inability of ascorbic acid to reduce cytochrome c associated with the HBM is attributed not to a change in its redox potential, but rather to the nature of the interaction of cytochrome c with the HBM.
Citation: Langmuir
Volume: 16
Issue: 14
Pages: pp. 5960 - 5966
Keywords: cytochrome c;hybrid bilayer membrane;nonlinear optics;second harmonic generation;surface enhanced resonance Raman
Research Areas: Spectroscopy, Life Sciences Research, Raman