Professor Bosse 65 Jahre

Holzwarth, Herbert

doi:10.1515/freq.1982.36.9.234

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…transfer becomes increasingly complex with an increased aggregation of biliproteins, ranging from monomers containing 2-6 chromophores up to intact phycobilisomes containing hundreds of chromophores. Following the early work of Merkelo et al (1969), mode-locked lasers have been used by several groups (see Breton and Geacintov, 1980;Brody, 1981;Holzwarth et al, 1982;Searle et al, 1978Searle et al, , 1979Pellegrino et al, 1981;Kobayashi er al., 1979) to obtain a more detailed picture on the excitation migration and fluorescence in biliproteins. Earlier picosecond studies have been reviewed by Breton and Geacintov (1980) and in a monograph edited by Alfano (1982).…”

Section: Introductionmentioning

confidence: 99%

Thermal Denaturation of Monomeric and Trimeric Phycocyanins Studied by Static and Polarized Time‐resolved Fluorescence Spectroscopy

Hefferle¹,

John²,

Scheer³

et al. 1984

Photochem & Photobiology

View full text Add to dashboard Cite

C-Phycocyanin (PC) and allophycocyanin (APC). as well as the a-subunit of PC. have been isolated from the blue-green alga (cyanobacterium). Spirulina platensis. The effects of partial thermal denaturation of PC and of its state of aggregation have been studied by ps time-resolved, polarized fluorescence spectroscopy. All measurements have been performed under low photon fluxes (< 10' ' photonsipulse x cm') to minimize singlet-singlet annihilation processes. A complex decay is obtained under most conditions, which can be fitted satisfactorily with a bi-exponential (7' = 70400 ps. T? = 1000-3000 ps) for both the isotropic and the polarized part, but with different intensities and time constants for the two decay curves. The data are interpreted in the frameworkof the model first developed by Teak and Dale (Biochern. J . 116, 161 (1970)], which divides the spectroscopically different chromophores in (predominantly) sensitizing (s) and fluorescing U, ones. If one assumes temperature dependent losses in the energy transfer from the s to the f and between f chromophores. both the biexponential nature of the isotropic fluorescence decay and the polarization data can be rationalized. In the isotropic emission (corresponding to the population of excited states) the short lifetime is related to the s-,f transfer. the longer one to the "free" decay of the final acceptor(s) (= f). The polarized part is dominated by an extremely short decay time. which is related to s+f transfer, as well as to resonance transfer between the f-chromophores.-<, . <, 22 1

show abstract

Section: Introductionmentioning

confidence: 99%