Binding of an import protein to intact chloroplasts and to isolated chloroplast envelopes of Chlamydomonas reinhardii

FEBS Letters

Su, Qing-iang¹  Boschetti, Arminio¹  Niklaus, Andreas¹  Rothen, René¹ 

[1] Institute of Biochemistry, Univervity of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland

关键词: Chloroplast envelope;    Chlamydomonas reinhardii;    Precursor protein;    Dissociation constant;    SS;    small subunit of ribulose-1;    5-bisphosphate carboxylase;    pSS;    precursor protein of SS;    pPC and pFD;    precursor proteins of plastocyanine and ferredoxin;    respectively;    K D;    dissociation constant;    Enzyme: Ribulose-1;    5-bisphosphate carboxylase/oxygenase (EC 4.1.1 39);   

DOI  :  10.1016/0014-5793(92)80186-K

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The binding affinity of the precursor of the small subunit of ribuloseo-1,5-bisphosphate carboxylase (pSS) to isolated, intact chloroplasts and to isolated chloroplast envelopes from the green alga Chlamydomonas reinhardii was studied under conditions where no import into chloroplasts occurred, pSS bound to both chloroplasts and envelopes with equally high affinity, The dissociation constants were 5.9 ± 2.1×10⁻⁹ M and 2.9 ± 1.4× 10⁻⁹ M, respectively. The number of binding sites per chloroplast was determined to be 8.1 ± 4.1×10⁴. Binding of pSS to isolated envelopes or intact chloroplasts was specific with respect to the type of the membrane and the presence of the transit sequence.

【 授权许可】

Unknown