Linked Life Data

8312265

Source:http://linkedlifedata.com/resource/pubmed/id/8312265

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1994-3-22
pubmed:abstractText
We report the fluorescence decay kinetics and the vibrational properties of chlorophyll a bound to the 47-kDa antenna protein (CP47) of spinach photosystem II. The chlorophyll fluorescence of CP47 samples decays with four lifetimes (tau = 75.8 ps, 1.05 ns, 3.22 ns, and 5.41 ns). The 75.8-ps and 3.22-ns components are associated with chlorophyll a bound to relatively intact centers, the 1.05-ns component corresponds to chlorophyll bound to centers that are slightly perturbed, and the the 5.41-ns phase probably originates from centers that are severely denatured. The resonance Raman spectrum of CP47 at 441.6 nm (this work) and at 406.7 nm [de Paula, J. C., Ghanotakis, D. F., Bowlby, N. R., Dekker, J. P., Yocum, C. F., & Babcock, G. T. (1990) in Current Research in Photosynthesis (Baltscheffsky, M., Ed.), Vol. I, pp 643-646, Kluwer Academic Publishers, Dordrecht, The Netherlands] shows heterogeneity in the C = O stretching region. This part of the spectrum monitors the environment of the keto group at position 9 of the chlorophyll a molecule. We show that several structurally distinct pools of chlorophyll a are bound to CP47. Four of these may be distinguished by their C9 = O stretching frequencies (nu C = O = 1670, 1688, 1693, and 1701 cm-1). By analyzing the resonance enhancement pattern of these modes, we ascribe the 1693-cm-1 vibration to denatured centers. Of the remaining populations, we propose that the 1670-cm-1 vibration is consistent with a hydrogen bond between the C9 = O group of chlorophyll a and the protein. We elaborate on the role of this chromophore-protein interaction in the mechanism of energy transfer within the 47-kDa antenna protein.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1455-66
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Structure-function relationships in the 47-kDa antenna protein and its complex with the photosystem II reaction center core: insights from picosecond fluorescence decay kinetics and resonance Raman spectroscopy.
pubmed:affiliation
Department of Chemistry, Haverford College, Pennsylvania 19041.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't