کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1988460 | 1063307 | 2007 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Near edge X-ray absorption fine structure spectroscopy (NEXAFS) of pigment–protein complexes: Peridinin–chlorophyll a protein (PCP) of Amphidinium carterae Near edge X-ray absorption fine structure spectroscopy (NEXAFS) of pigment–protein complexes: Peridinin–chlorophyll a protein (PCP) of Amphidinium carterae](/preview/png/1988460.png)
Peridinin–chlorophyll a protein (PCP) is a unique water soluble antenna complex that employs the carotenoid peridinin as the main light-harvesting pigment. In the present study the near edge X-ray absorption fine structure (NEXAFS) spectrum of PCP was recorded at the carbon K-edge. Additionally, the NEXAFS spectra of the constituent pigments, chlorophyll a and peridinin, were measured. The energies of the lowest unoccupied molecular levels of these pigments appearing in the carbon NEXAFS spectrum were resolved. Individual contributions of the pigments and the protein to the measured NEXAFS spectrum of PCP were determined using a “building block” approach combining NEXAFS spectra of the pigments and the amino acids constituting the PCP apoprotein. The results suggest that absorption changes of the pigments in the carbon near K-edge region can be resolved following excitation using a suitable visible pump laser pulse. Consequently, it may be possible to study excitation energy transfer processes involving “optically dark” states of carotenoids in pigment–protein complexes by soft X-ray probe optical pump double resonance spectroscopy (XODR).
Journal: Journal of Biochemical and Biophysical Methods - Volume 70, Issue 3, 10 April 2007, Pages 369–376