Femtosecond spectroscopy of primary charge separation in modified reaction centers of Rhodobacter sphaeroides (R‐26)

FEBS Letters

Shkuropatov, A.Ya.²  Shuvalov, V.A.²  Yartzev, A.P.¹  Matveetz, Ya.A.¹  Chekalin, S.V.¹ 

[1] >Institute of Spectroscopy, Troitzk USSR;Institute of Soil Science and Photosynthesis, USSR Academy of Sciences, Pushchino, Moscow Region, USSR

关键词: Reaction center;    Bacteriochlorophyll;    Bacteriopheophytin;    Charge separation;    BChl;    bacteriochlorophyll;    Bph or H;    bacteriopheophytin;    BL and BM;    BChl molecules located in L and M protein subunits of reaction centers;    respectively;    HL and HM;    Bph located in L and M subunits;    respectively;   

DOI  :  10.1016/0014-5793(87)80698-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Femtosecond measurements of kinetics and spectra of absorbance changes (ΔA) were carried out with modified reaction centers (RCs) from Rhodobacter sphaeroides (R-26) from which nonactive bacteriochlorophyll BM (located in the M protein subunit) was removed. The band of BM at 800 nm in native RCs is shifted in femtosecond measurements and obscures the ΔA of active bacteriochlorophyll BL (L subunit). The spectrum of ΔA in modified RCs at 6 ps delay includes the bleachings of the bands of P (primary electron donor) at 870 nm, of BL at 805 nm and of HL (bacteriopheophytin located in the L subunit) at 755 nm showing the reduction of 0̃.5 mol BL and 0̃.5 mol HL per mol P⁺. These data confirm an earlier suggestion that BL participates as an electron acceptor in the light-induced primary charge separation and agree with recent X-ray analysis of Rhodopseudomonas viridis and R. sphaeroides RCs which shows a location of BL between P and HL.

【 授权许可】

Unknown