Spermine is a potent modulator of proton transport through LHCII
2015
Tsiavos, Theodoros | Ioannidis, Nikolaos E. | Tsortos, Achilleas | Gizeli, Electra | Kotzabasis, Kiriakos
The effect of spermine on proton transport across large unilamellar liposomes containing incorporated complexes of the PSII antenna has been studied with the application of a pH-sensitive dye entrapped inside the vesicles. Both monomeric LHCbs and trimeric LHCII increased the permeability of proteoliposomes to protons when in a partly aggregated state within the lipid membrane. We have previously shown that a spermine-induced conformational change in LHCII results in its aggregation and ultimately in the enhancement of excitation energy as heat (qE). In this paper, spermine-induced aggregation of LHCII was found to facilitate proton transport across the proteoliposomes, indicating that a second protective mechanism (other than qE) might exist and might be regulated in vivo by polyamines when photosynthesis is saturated in excess light.
显示更多 [+] 显示较少 [-]