| 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 |
