Abstract:
:Stepwise two-photon excitation of chlorophyll a and b in the higher plant main light-harvesting complex (LHC II) and the minor complex CP29 (as well as in organic solution) with 100-fs pulses in the Q(y) region results in a weak blue fluorescence. The dependence of the spectral shape of the blue fluorescence on excitation wavelength offers a new approach to elucidate the long-standing problem of the origin of spectral "chlorophyll forms" in pigment-protein complexes, in particular the characterization of chlorophyll a/b-heterodimers. As a first result we present evidence for the existence of strong chlorophyll a/b-interactions (excitonically coupled transitions at 650 and 680 nm) in LHC II at ambient temperature. In comparison with LHC II, the experiments with CP29 provide further evidence that the lowest energy chlorophyll a transition (at approximately 680 nm) is not excitonically coupled to chlorophyll b.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Leupold D,Teuchner K,Ehlert J,Irrgang KD,Renger G,Lokstein Hdoi
10.1016/S0006-3495(02)75509-4subject
Has Abstractpub_date
2002-03-01 00:00:00pages
1580-5issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(02)75509-4journal_volume
82pub_type
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