A novel and mild isolation procedure of chlorosomes from the green sulfur bacterium Chlorobaculum tepidum

作者：Tokita Seiji^*; Shimada Keizo; Watabe Kazuyuki; Matsuura Katsumi; Mimuro Mamoru

来源：Photosynthesis Research, 2011, 108(2-3): 183-190.

DOI：10.1007/s11120-011-9679-4

• Isolation method
• Chlorosomes
• FMO protein
• Low-temperature absorption
• Chlorobaculum tepidum

In this article, we developed a new and mild procedure for the isolation of chlorosomes from a green sulfur bacterium Chlorobaculum tepidum. In this procedure, Fenna-Matthews-Olson (FMO) protein was released by long cold treatment (6 degrees C) of cells under the presence of a chaotrope (2 M NaSCN) and 0.6 M sucrose. Chlorosomes were released by an osmotic shock of the cold-treated cells after the formation of spheroplasts without mechanical disruption. Chlorosomes were finally purified by a sucrose step-wise density gradient centrifugation. We obtained two samples with different density (20 and 23% sucrose band, respectively) and compared them by SDS-PAGE, absorption spectroscopy at 80 K, fluorescence and CD spectroscopy at room temperature. Cells whose absorption maximum was longer than 750 nm yielded higher amount of the 20% sucrose fraction than those having an absorption maximum shorter than 750 nm.

• 出版日期2011-9