Fluorescence of native and carotenoid‐depleted LH2 from Chromatium minutissimum, originating from simultaneous two‐photon absorption in the spectral range of the presumed (optically ‘dark’) S1 state of carotenoids

• Published in: FEBS letters Vol. 528; no. 1-3; pp. 227 - 229
• Main Authors: Krikunova, M, Kummrow, A, Voigt, B, Rini, M, Lokstein, H, Moskalenko, A, Scheer, H, Razjivin, A, Leupold, D
• Format: Journal Article
• Language: English
• Published: 25-09-2002
• Subjects: (B)Chl, (bacterio)chlorophyll; Carotenoid-less; Chromatium minutissimum; EET, excitation energy transfer; Excitation energy transfer; IC, internal conversion; LH2, peripheral purple bacterial light-harvesting complex; NIR, near infra-red; Rhodopsin; TPA, (simultaneous) two-photon absorption; TPF, (simultaneous) two-photon excited fluorescence; Two-photon excited fluorescence
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(02)03315-X

Native and carotenoid‐depleted peripheral purple bacterial light‐harvesting complex (LH2) were investigated by simultaneous two‐photon excited (between 1300–1500 nm) fluorescence (TPF). TPF results from direct bacteriochlorophyll excitation in both samples. The spectral position of the 2Ag
− state of rhodopsin is indicated by a diminuition of the bacteriochlorophyll TPF in native LH2. In conclusion, comparison to carotenoid‐depleted samples is a conditio sine qua non for unambiguous interpretation of similar experiments.