TY - JOUR
T1 - Morphology and spectroscopy of chlorosomes from Chlorobium tepidum by alcohol treatments
AU - Wang, Zheng Yu
AU - Marx, Giselher
AU - Umetsu, Mitsuo
AU - Kobayashi, Masayuski
AU - Mimuro, Mamoru
AU - Nozawa, Tsunenori
N1 - Funding Information:
We are grateful to Prof. M. Konno for the DLS and EM measurements. The technical assistance of Y. Imamura is gratefully acknowledged. This work is partly supported by a Grant-in-Aid from the Ministry of Education, Science and Culture, Japan (No. 07750872).
PY - 1995/12/12
Y1 - 1995/12/12
N2 - Chlorosomes from Chlorobium tepidum have been treated with alcohol-saturated buffers, followed by dilution to the buffers with half the saturated concentrations. Morphologic changes during this process have been statistically investigated by dynamic light scattering technique combined with electron microscopy to obtain the complete information on shape, size and distribution, while spectral properties have been studied by absorption, CD and magnetic circular dichroism. Three alcohols (1-hexanol, 1-butanol and phenol) have been found to produce nearly reversible conversion of absorption spectra despite the more than 15-times difference in the alcohol concentration. It is shown that the degree of saturation, not the alcohol concentration, is the key factor for the complete conversion of bacteriochlorophyll c in chlorosomes from the aggregated state to the monomeric form. We have observed substantial changes in the shape, size and distribution at each step of the treatment with 1-hexanol, indicating that the whole process is morphologically irreversible. Comparison of the morphologic changes with the corresponding spectroscopic behaviour suggests that the relative overall size rather than the shape and distribution may be a more important factor affecting the spectral properties.
AB - Chlorosomes from Chlorobium tepidum have been treated with alcohol-saturated buffers, followed by dilution to the buffers with half the saturated concentrations. Morphologic changes during this process have been statistically investigated by dynamic light scattering technique combined with electron microscopy to obtain the complete information on shape, size and distribution, while spectral properties have been studied by absorption, CD and magnetic circular dichroism. Three alcohols (1-hexanol, 1-butanol and phenol) have been found to produce nearly reversible conversion of absorption spectra despite the more than 15-times difference in the alcohol concentration. It is shown that the degree of saturation, not the alcohol concentration, is the key factor for the complete conversion of bacteriochlorophyll c in chlorosomes from the aggregated state to the monomeric form. We have observed substantial changes in the shape, size and distribution at each step of the treatment with 1-hexanol, indicating that the whole process is morphologically irreversible. Comparison of the morphologic changes with the corresponding spectroscopic behaviour suggests that the relative overall size rather than the shape and distribution may be a more important factor affecting the spectral properties.
KW - (Green bacterium)
KW - Alcohol treatment
KW - Antenna
KW - Chlorosome
KW - Hydrodynamic diameter
KW - Morphology
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U2 - 10.1016/0005-2728(95)00113-1
DO - 10.1016/0005-2728(95)00113-1
M3 - Article
AN - SCOPUS:0028804243
VL - 1232
SP - 187
EP - 196
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 3
ER -