Investigation of reaction mechanisms of cytochrome c and mitochondria with transient absorption spectroscopy

摘要

We performed Transient Absorption Spectroscopy (TAS) on samples of cytochrome c in its reduced and oxidized statesas well as mitochondria, and we use kinetic analysis to determine the decay rates of the transients. We also tested thesamples following red light exposures to determine if there were any changes in transient decay rates. Mitochondria wereisolated from hTERT-RPE1 cells and were tested in a glutamate buffer solution while cytochrome c was tested in a SodiumPhosphate solution (Na_2PO_4). Femtosecond TAS was performed with a pump pulse with wavelength centered at 418 nmand a supercontinuum probe pulse with a spectrum between 440 and 760 nm. Red light illuminations were performed witha 635 nm continuous wave light source at an intensity of 1.6 mW/cm~2 for 0.5 hours. We find transients and kinetic decayrates for reduced and oxidized cytochrome c that are consistent with previous literature. However, we do not find anytransients for mitochondria under our current TAS testing parameters, and we expect that this may be due to low Signalto-Noise ratio or choice of pump wavelength.