title: The low energy emitting states of the Lhca4 subunit of higher plant photosystem I.
abstract: The selectively red excited emission spectrum, at room temperature, of the in vitro reconstituted Lhca4, has a pronounced non-equilibrium distribution, leading to enhanced emission from the directly excited low-energy pigments. Two different emitting forms (or states), with maximal emission at 713 and 735nm (F713 and F735) and unusual spectral properties, have been identified. Both high-energy states are populated when selective excitation is into the F735 state and the fluorescence anisotropy spectrum attains the value of 0.3 in the wavelength region where both emission states are present. This indicates that the two states are on the same Lhca4 complex and have transition dipoles with similar orientation.
authors.affiliation: Istituto di Biofisica del Consiglio Nazionale delle Ricerche - Sezione di Milano, Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy. giuseppe.zucchelli@unimi.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zucchelli
authors.forename: Tomas
authors.initials: T
authors.lastname: Morosinotto
authors.forename: Flavio M
authors.initials: FM
authors.lastname: Garlaschi
authors.forename: Roberto
authors.initials: R
authors.lastname: Bassi
authors.forename: Robert C
authors.initials: RC
authors.lastname: Jennings
mesh_terms: D061146:Chlorophyll Binding Proteins; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry*; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D061146:Chlorophyll Binding Proteins; D045342:Light-Harvesting Protein Complexes; D045331:Photosystem I Protein Complex; D010940:Plant Proteins