Effect of biogenic polyamine spermine on the structure and function of photosystem I

Characterization of the structural changes and photochemical activity of photosystem I under Al3+ effect

“…The observed structural changes were probably related to the electrostatic Al 3+ -proteins interaction [66]. The interaction of cations with PSI proteins was also reported in the presence of Pb 2+ and spermine, a heavy metal and an organic cation, respectively [28,57]. Moreover, Hu et al [20] have suggested that the conformational changes of protein secondary structures in PSI complex were accompanied by energetic disconnection of LHCI from PSI core and denaturation of PSI complex under heat stress.…”

“…See Section 2 for details. [28,43,57]. From the lowest Al 3+ concentration, some changes in the structural components of the amide I band were observed.…”

“…This technique was widely used to give detailed information about the secondary structures of PSI proteins [28,43,56,57]. The decomposition of amide I bands and the quantitative secondary structures analysis measured from control (free PSI) and Al 3+ -PSI complexes with different Al 3+ concentrations are Fig.…”

The role of putrescine in the regulation of proteins and fatty acids of thylakoid membranes under salt stress

“…Several studies have shown that external PAs can regulate changes of endogenous PAs and reorganization of the photosynthetic apparatus in response to adverse environments 1 11 14 . Our previous study found that PAs in chloroplasts play crucial roles in protecting thylakoid membranes against the deleterious influences of salt stress 1 .…”

“…The role of PAs in stress resistance and their association with thylakoid membrane proteins indicate that PAs are also likely to interact directly with photosystem components. Yaakoubi et al 14 demonstrated that Spm can interact with photosystem I (PSI) sub-membrane fractions and protect PSI photochemical activity against photoinhibition induced by high light stress. Application of exogenous Put has been reported to alter the content of light-harvesting complex II (LHCII) monomers and oligomers as well as PSI and PSII core proteins in thylakoid membranes of Scenedesmus , thereby improving photo-adaptability of that species 15 .…”