Picosecond fluorescence of cryptomonad biliproteins. Effects of excitation intensity and the fluorescence decay times of phycocyanin 612, phycocyanin 645, and phycoerythrin 545

D. Guard-Friar, R. MacColl, D. S. Berns, Bruce Paul Wittmershaus, R. S. Knox

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The fluorescence of purified biliproteins (phycocyanin 645, phycocyanin 612, and phycoerythrin 545) from three cryptomonads, Chroomonas species, Hemiselmis virescens, and Rhodomonas lens, and C-phycocyanin from Anacystis nidulans has been time resolved in the picosecond region with a streak camera system having less than or equal to 2-ps jitter. The fluorescence lifetimes of phycocyanins from Chroomonas species and Hemiselmis virescens are 1.5 +/- 0.2 ns and 2.3 +/- 0.2 ns, respectively, regardless of the fluence of the 30 ps, 532-nm excitation pulse. (Fluence [or photons/cm2] = f intensity [photons/cm2s]dt.). In contrast, that of C-phycocyanin is 2.3 +/- 0.2 ns when the excitation fluence is 8.2 X 10(11) photons/cm2 and decreases to a decay approximated by an exponential decay time of 0.65 +/- 0.1 ns at 7.2 X 10(16) photons/cm2. The cryptomonad phycoerythrin fluorescence decay lifetime is also dependent on intensity, having a decay time of 1.5 +/- 0.1 ns at low fluences and becoming clearly biphasic at higher fluences (greater than 10(15) photons/cm2). We interpret the shortening of decay times for C-phycocyanin and phycoerythrin 545 in terms of exciton annihilation, and have discussed the applicability of exciton annihilation theories to the high fluence effects.

Original languageEnglish (US)
Pages (from-to)787-793
Number of pages7
JournalBiophysical journal
Volume47
Issue number6
DOIs
StatePublished - Jan 1 1985

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Cryptophyta
Phycocyanin
Photons
Fluorescence
Phycoerythrin
Lenses
phycoerythrin 545
phycocyanin 612

All Science Journal Classification (ASJC) codes

  • Biophysics

Cite this

@article{51039f101234475089c12ff8e294559a,
title = "Picosecond fluorescence of cryptomonad biliproteins. Effects of excitation intensity and the fluorescence decay times of phycocyanin 612, phycocyanin 645, and phycoerythrin 545",
abstract = "The fluorescence of purified biliproteins (phycocyanin 645, phycocyanin 612, and phycoerythrin 545) from three cryptomonads, Chroomonas species, Hemiselmis virescens, and Rhodomonas lens, and C-phycocyanin from Anacystis nidulans has been time resolved in the picosecond region with a streak camera system having less than or equal to 2-ps jitter. The fluorescence lifetimes of phycocyanins from Chroomonas species and Hemiselmis virescens are 1.5 +/- 0.2 ns and 2.3 +/- 0.2 ns, respectively, regardless of the fluence of the 30 ps, 532-nm excitation pulse. (Fluence [or photons/cm2] = f intensity [photons/cm2s]dt.). In contrast, that of C-phycocyanin is 2.3 +/- 0.2 ns when the excitation fluence is 8.2 X 10(11) photons/cm2 and decreases to a decay approximated by an exponential decay time of 0.65 +/- 0.1 ns at 7.2 X 10(16) photons/cm2. The cryptomonad phycoerythrin fluorescence decay lifetime is also dependent on intensity, having a decay time of 1.5 +/- 0.1 ns at low fluences and becoming clearly biphasic at higher fluences (greater than 10(15) photons/cm2). We interpret the shortening of decay times for C-phycocyanin and phycoerythrin 545 in terms of exciton annihilation, and have discussed the applicability of exciton annihilation theories to the high fluence effects.",
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Picosecond fluorescence of cryptomonad biliproteins. Effects of excitation intensity and the fluorescence decay times of phycocyanin 612, phycocyanin 645, and phycoerythrin 545. / Guard-Friar, D.; MacColl, R.; Berns, D. S.; Wittmershaus, Bruce Paul; Knox, R. S.

In: Biophysical journal, Vol. 47, No. 6, 01.01.1985, p. 787-793.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Picosecond fluorescence of cryptomonad biliproteins. Effects of excitation intensity and the fluorescence decay times of phycocyanin 612, phycocyanin 645, and phycoerythrin 545

AU - Guard-Friar, D.

AU - MacColl, R.

AU - Berns, D. S.

AU - Wittmershaus, Bruce Paul

AU - Knox, R. S.

PY - 1985/1/1

Y1 - 1985/1/1

N2 - The fluorescence of purified biliproteins (phycocyanin 645, phycocyanin 612, and phycoerythrin 545) from three cryptomonads, Chroomonas species, Hemiselmis virescens, and Rhodomonas lens, and C-phycocyanin from Anacystis nidulans has been time resolved in the picosecond region with a streak camera system having less than or equal to 2-ps jitter. The fluorescence lifetimes of phycocyanins from Chroomonas species and Hemiselmis virescens are 1.5 +/- 0.2 ns and 2.3 +/- 0.2 ns, respectively, regardless of the fluence of the 30 ps, 532-nm excitation pulse. (Fluence [or photons/cm2] = f intensity [photons/cm2s]dt.). In contrast, that of C-phycocyanin is 2.3 +/- 0.2 ns when the excitation fluence is 8.2 X 10(11) photons/cm2 and decreases to a decay approximated by an exponential decay time of 0.65 +/- 0.1 ns at 7.2 X 10(16) photons/cm2. The cryptomonad phycoerythrin fluorescence decay lifetime is also dependent on intensity, having a decay time of 1.5 +/- 0.1 ns at low fluences and becoming clearly biphasic at higher fluences (greater than 10(15) photons/cm2). We interpret the shortening of decay times for C-phycocyanin and phycoerythrin 545 in terms of exciton annihilation, and have discussed the applicability of exciton annihilation theories to the high fluence effects.

AB - The fluorescence of purified biliproteins (phycocyanin 645, phycocyanin 612, and phycoerythrin 545) from three cryptomonads, Chroomonas species, Hemiselmis virescens, and Rhodomonas lens, and C-phycocyanin from Anacystis nidulans has been time resolved in the picosecond region with a streak camera system having less than or equal to 2-ps jitter. The fluorescence lifetimes of phycocyanins from Chroomonas species and Hemiselmis virescens are 1.5 +/- 0.2 ns and 2.3 +/- 0.2 ns, respectively, regardless of the fluence of the 30 ps, 532-nm excitation pulse. (Fluence [or photons/cm2] = f intensity [photons/cm2s]dt.). In contrast, that of C-phycocyanin is 2.3 +/- 0.2 ns when the excitation fluence is 8.2 X 10(11) photons/cm2 and decreases to a decay approximated by an exponential decay time of 0.65 +/- 0.1 ns at 7.2 X 10(16) photons/cm2. The cryptomonad phycoerythrin fluorescence decay lifetime is also dependent on intensity, having a decay time of 1.5 +/- 0.1 ns at low fluences and becoming clearly biphasic at higher fluences (greater than 10(15) photons/cm2). We interpret the shortening of decay times for C-phycocyanin and phycoerythrin 545 in terms of exciton annihilation, and have discussed the applicability of exciton annihilation theories to the high fluence effects.

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SP - 787

EP - 793

JO - Biophysical Journal

JF - Biophysical Journal

SN - 0006-3495

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