Partial degradation of the extrinsic 23-kDa protein of the Photosystem II complex of spinach

Mitsue Miyao, Yoko Fujimura, Norio Murata

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)

Abstract

Chymotrypsin eliminated nine amino acid residues at the amino-terminal side of the extrinsic 23-kDa protein of the oxygen-evolving Photosystem II complex of spinach. The resultant 22-kDa fragment was able to bind to the Photosystem II complex but with lowered binding affinity. However, once the 22-kDa fragment bound to the complex, it retained most functions of the 23-kDa protein; the fragment provided a binding site for the extrinsic 18-kDa protein, preserved a tight trap for Ca2+ in the complex, and shifted the optimum Cl- concentration for oxygen evolution from 30 to 10 mM, although it was less effective in sustaining oxygen evolution at Cl- concentrations below 10 mM. These observations suggest that the elimination of nine amino acid residues at the amino-terminal region of the 23-kDa protein does not significantly alter the conformation of the protein, except for partial modification of its binding site and its interaction with Cl-.

Original languageEnglish
Pages (from-to)465-474
Number of pages10
JournalBBA - Bioenergetics
Volume936
Issue number3
DOIs
Publication statusPublished - 1988 Dec 7
Externally publishedYes

Keywords

  • (Spinach)
  • Extrinsic 23 kDa protein
  • Oxygen evolution
  • Photosynthesis
  • Photosystem II

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

Fingerprint

Dive into the research topics of 'Partial degradation of the extrinsic 23-kDa protein of the Photosystem II complex of spinach'. Together they form a unique fingerprint.

Cite this