STARK-EFFECT SPECTROSCOPY OF BACTERIOCHLOROPHYLL IN LIGHT-HARVESTING COMPLEXES FROM PHOTOSYNTHETIC BACTERIA

被引:61
作者
GOTTFRIED, DS [1 ]
STOCKER, JW [1 ]
BOXER, SG [1 ]
机构
[1] STANFORD UNIV, DEPT CHEM, STANFORD, CA 94305 USA
基金
美国国家科学基金会;
关键词
STARK EFFECT; ELECTRIC FIELD EFFECT; ANTENNA COMPLEX; LIGHT HARVESTING COMPLEX; ENERGY TRANSFER;
D O I
10.1016/S0005-2728(05)80188-4
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The effects of an applied electric field on the Q(y) absorption and fluorescence spectra of three antenna complexes from photosynthetic bacteria have been measured at 77 K: the bacteriochlorophyll a protein (BCP) from Prosthecochloris aestuarii, the B800-850 light-harvesting complex from Rhodobacter sphaeroides and the B875 light-harvesting complex from Rhodobacter capsulatus. For BCP in a glycerol/buffer glass, the value of the change in dipole moment, \DELTA-mu-A\, for three of the resolved absorption bands was found to lie in the range 1.3-2.0 D/f (where f is the local field correction factor), and the Stark spectrum lineshape is well approximated by the second derivative of the absorption. This is similar to what is found for monomeric bacteriochlorophyll a (BChl a) embedded in a polymer film and for the 800 nm monomer BChl a band of Rb. sphaeroides reaction centers; thus, the BChl a chromophores in BCP behave largely as a non-interacting set in an electric field. For B800-850 in a glycerol/buffer glass, the BChl a associated with the 800 nm band has a small \DELTA-mu-A\ = 0.8-0.9 D/f, while the BChl a of the 850 nm band is found to have \DELTA-mu-A\ = 3.1-3.4 D/f; however, the Stark spectra of both components have anomalous lineshapes, which complicates the quantitative analysis. \DELTA-mu-A\ for the 850 nm band is nearly unchanged upon attenuation of the 800 nm band by treatment with lithium dodecyl sulfate. The Stark spectrum of the B875 complex was obtained in whole chromatophore membranes. The lineshape for B875 is also unusual, and it appears that the electrochromism is not dominated by a dipole moment change. In all three antenna complexes, efficient energy transfer occurs from higher-energy states to the lowest-energy excited state, and, at 77 K, fluorescence occurs primarily from this lowest state. The electric field modulated fluorescence of BCP shows nearly the same quantitative effect as that obtained from absorption, with \DELTA-mu-F\ = 1.6 D/f. In contrast, the B800-850 complex shows an unprecedented, very large net decrease in fluorescence in an applied electric field. Possible mechanisms for this unusual result are discussed. B875 also shows an electric field induced fluorescence decrease; however, the Stark fluorescence spectrum is dominated by a first-derivative contribution, not unlike the electromodulated absorption spectrum. Explanations for this, and many of the results for strongly interacting chromophores, may lie in a breakdown of the standard treatments of electrochromism when strong intermolecular coupling dominates.
引用
收藏
页码:63 / 75
页数:13
相关论文
共 61 条
[1]  
ALLEN JP, 1985, ANTENNAS REACTION CT, P82
[2]   CRITICAL REFINEMENT OF THE THEORY OF INTEGRAL ELECTRO-OPTICAL EMISSION MEASUREMENTS [J].
BAUMANN, W ;
BISCHOF, H .
JOURNAL OF MOLECULAR STRUCTURE, 1985, 129 (1-2) :125-136
[3]   CHARACTERIZATION OF EXCITATION-ENERGY TRAPPING IN PHOTOSYNTHETIC PURPLE BACTERIA AT 77-K [J].
BERGSTROM, H ;
VANGRONDELLE, R ;
SUNDSTROM, V .
FEBS LETTERS, 1989, 250 (02) :503-508
[4]   OBSERVATION OF A NEW LOW-ENERGY FLUORESCENT 1(PI,PI-STAR) EXCITED-STATE IN STRONGLY COUPLED PORPHYRIN DIMERS [J].
BILSEL, O ;
RODRIGUEZ, J ;
HOLTEN, D ;
GIROLAMI, GS ;
MILAM, SN ;
SUSLICK, KS .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1990, 112 (10) :4075-4077
[5]   LINEAR DICHROISM OF LIGHT HARVESTING BACTERIOCHLOROPHYLL PROTEINS FROM RHODOPSEUDOMONAS-SPHAEROIDES IN STRETCHED POLYVINYL-ALCOHOL FILMS [J].
BOLT, J ;
SAUER, K .
BIOCHIMICA ET BIOPHYSICA ACTA, 1979, 546 (01) :54-63
[6]   LINEAR AND CIRCULAR-DICHROISM OF MEMBRANES FROM RHODOPSEUDOMONAS-CAPSULATA [J].
BOLT, JD ;
SAUER, K ;
SHIOZAWA, JA ;
DREWS, G .
BIOCHIMICA ET BIOPHYSICA ACTA, 1981, 635 (03) :535-541
[7]   LINEAR AND CIRCULAR-DICHROISM AND FLUORESCENCE POLARIZATION OF THE B875 LIGHT-HARVESTING BACTERIOCHLOROPHYLL-PROTEIN COMPLEX FROM RHODOPSEUDOMON AS SPHAEROIDES [J].
BOLT, JD ;
HUNTER, CN ;
NIEDERMAN, RA ;
SAUER, K .
PHOTOCHEMISTRY AND PHOTOBIOLOGY, 1981, 34 (05) :653-656
[8]  
BOXER SG, 1987, SPRINGER P PHYS, V20, P80
[9]   ISOLATION AND CHARACTERIZATION OF THE PIGMENT-PROTEIN COMPLEXES OF RHODOPSEUDOMONAS-SPHAEROIDES BY LITHIUM DODECYL SULFATE-POLYACRYLAMIDE GEL-ELECTROPHORESIS [J].
BROGLIE, RM ;
HUNTER, CN ;
DELEPELAIRE, P ;
NIEDERMAN, RA ;
CHUA, NH ;
CLAYTON, RK .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1980, 77 (01) :87-91
[10]   THE EFFECTS OF LITHIUM DODECYL-SULFATE AND SODIUM-BOROHYDRIDE ON THE ABSORPTION-SPECTRUM OF THE B800-850 LIGHT-HARVESTING COMPLEX FROM RHODOPSEUDOMONAS-ACIDOPHILA 7750 [J].
CHADWICK, BW ;
ZHANG, CY ;
COGDELL, RJ ;
FRANK, HA .
BIOCHIMICA ET BIOPHYSICA ACTA, 1987, 893 (03) :444-451