A difference Fourier-transform infrared study of two redox-active tyrosine residues in photosystem II.
AUTOR(ES)
MacDonald, G M
RESUMO
Photosystem II, the photosynthetic water-oxidizing complex, contains two redox-active tyrosine residues. Although current models suggest that these tyrosines are located in symmetric positions in the reaction center, there are functional differences between them. To elucidate those structural factors that give rise to this functional asymmetry, we have used difference Fourier-transform infrared spectroscopy to obtain the vibrational difference spectrum associated with the oxidation of each of these redox-active residues. Isotopic labeling was employed to definitively assign vibrational lines to the redox-active tyrosines. This work has shown that the vibrational spectra of the two redox-active species are significantly different from each other. This result suggests that the structure of the redox-active residue helps to determine its role in electron transfer in the reaction center.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=47914Documentos Relacionados
- Millisecond Fourier-transform infrared difference spectra of bacteriorhodopsin's M412 photoproduct.
- Chemical complementation identifies a proton acceptor for redox-active tyrosine D in photosystem II
- Proximity of the manganese cluster of photosystem II to the redox-active tyrosine YZ.
- Fourier-Transform Raman and Fourier-Transform Infrared Spectroscopy (An Investigation of Five Higher Plant Cell Walls and Their Components).
- Human colorectal cancers display abnormal Fourier-transform infrared spectra.