Skip to main content

Temperature dependence of the formation of the g ~ 5 EPR signal in the oxygen evolving complex of photosystem II

Abstract

The temperature dependence of the formation of the g ~ 5 S2 state electron paramagnetic resonance (EPR) signal in photosystem II (PSII) was investigated. The g ~ 5 signal was produced at an illumination above 200 K. The half inhibition temperature of the formation of the g ~ 5 EPR signal was approximately 215 K. The half inhibition temperature is close to that of the transition from the S2 state-to-S3 state in the untreated PSII, and not to that of the transition from S1 state -to-S2 state in the untreated PSII. The upshift of the half inhibition temperature of the transition from the S1 state -to-S2 state (g ~ 5) reflects the structural change upon transition from the S1 state to the S2 state. The activation energy of the g ~ 5 state formation was estimated as 40.7 ± 4.4 kJ/mol, which is comparable to the reported activation energy for the S2 formation in the untreated PSII. The activation enthalpy and entropy were estimated to be 39.0 ± 4.4 kJ/mol and − 103 ± 19 J/mol K at 210 K, respectively. Based on these parameters, the formation process of the g ~ 5 state is discussed in this study.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

References

Download references

Funding

This work was partly supported by a Nanotechnology Platform Program < Molecule and Material Synthesis > (JPMXP0S21MS1007) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan (to H.M), and JSPS KAKENHI Grant No. JP20H05096 (to H.M.).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hiroyuki Mino.

Ethics declarations

Conflict of interest

The authors declare no competing financial interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Mino, H. Temperature dependence of the formation of the g ~ 5 EPR signal in the oxygen evolving complex of photosystem II. Photosynth Res (2022). https://doi.org/10.1007/s11120-022-00916-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11120-022-00916-9

Keywords

  • Photosystem II
  • Oxygen-evolving complex
  • Mn cluster
  • EPR
  • ESR