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Start Over Creator Qu, Y.-G.

1. Energy transfer of aromatic amino acids in photosystem 2 core antenna complexes CP43 and CP47

Creator:
Qu, Y.-G., Qin, X.-C., Wang, W.-F., Li, L.-B., and Kuang, T.-Y.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
absorpton, β-carotene, chlorophyll, fluorescence, model, proteins, tryptophan, and tyrosine
Language:
Multiple languages
Description:
Energy transfer of aromatic amino acids in photosystem 2 (PS2) core antenna complexes CP43 and CP47 was studied using absorption spectroscopy, fluorescence spectroscopy, and the 0.35 nm crystal structure of PS2 core complex. The energy of tyrosines (Tyrs) was not effectively transferred to tryptophans (Trps) in CP43 and CP47. The fluorescence emission spectrum of CP43 and CP47 by excitation at 280 nm should be a superposition of the Tyr and Trp fluorescence emission spectra. The aromatic amino acids in CP43 and CP47 could transfer their energy to chlorophyll (Chl) a molecules by the Dexter mechanism and the Föster mechanism, and the energy transfer efficiency in CP47 was much higher than that in CP43. In CP47 the Föster mechanism must be the dominant energy transfer mechanism between aromatic amino acids and Chl a molecules, whereas in CP43 the Dexter mechanism must be the dominant one. Hence solar ultraviolet radiation brings not only damages but also benefits to plants. and Y. G. Qu .... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Structural characteristics of extra-membrane domains and guanidine hydrochloride-induced denaturation of photosystem 2 core antenna complexes CP43 and CP47

Creator:
Qu, Y.-G., Gong, Y.-D., Guo, S.-K., Li, L.-B., and Kuang, T.-Y.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
aromatic amino acid, chlorophyll, circular dichronism, CP43, CP47, denaturation, energy transfer, extramembrane domain, fluorescence, guanidine hydrochloride, and β-carotene
Language:
Multiple languages
Description:
The structural characteristics of the extra-membrane domains and guanidine hydrochloride-induced denaturation of photosystem 2 (PS2) core antenna complexes CP43 and CP47 were investigated using fluorescence emission and circular dichroism (CD) spectra. The extra-membrane domains of CP43 and CP47 possessed a certain degree of secondary and tertiary structure and not a complete random coil conformation. The tertiary structure and the chlorophyll (Chl) a microenvironment of CP47 were more sensitive to guanidine hydrochloride (GuHCl) than that of CP43. Changes in energy transfer from β-carotene to Chl a corresponded well to changes in the tertiary structure while their correlation with changes in the secondary structure was rather poor. Unlike most of water-soluble proteins, both CP43 and CP47 are partly resistant to denaturation induced by guanidine hydrochloride (GuHCl); the denaturation of CP43 or CP47 is not a two-state process. Those features most probably reflect their character as intrinsic membrane proteins. and Y.-G. Qu ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public