Intermolecular hydrogen bonding between carotenoid and bacteriochlorophyll in LH2

FEBS Letters

Pullerits, Tõnu¹  Sundström, Villy¹  He, Zhi¹ 

[1] Department of Chemical Physics, Lund University, P.O. Box 124, S-22100 Lund, Sweden

关键词: Light-harvesting complex II;    Bacteriochlorophyll;    Carotenoid;    Ab initio calculation;    Hydrogen bond;    LH2;    light-harvesting antenna II;    BChl;    bacteriochlorophyll;    B800;    bacteriochlorophyll absorbing at 800 nm;    HF;    Hartree–Fock calculation;    CIS;    CI-singles approach;    TDDFT;    time-dependent density functional theory;   

DOI  :  10.1016/S0014-5793(01)02400-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have studied van der Waals contacts of the carotenoid rhodopin glucoside (RG) with the bacteriochlorophyll pigments absorbing at 800 nm (B800) in the crystal structure of Rhodopseudomonas acidophila, and the hydrogen positions were determined from quantum chemical calculations at the Hartree–Fock (6-31G) level. We have found strong evidence for hydrogen bonding between the B800 BChl and the RG from neighboring protomer units. The binding energy was estimated to be about 2 kcal/mol (700 cm⁻¹). CI-singles approach and time-dependent density functional theory calculations of the B800–RG dimer indicate a red-shift (ca 2 nm) of the B800 Q _y transition, along with a substantial increase of its oscillator strength, probably due to the hydrogen bonding.

【 授权许可】

Unknown