Sulfitolysis and thioredoxin‐dependent reduction reveal the presence of a structural disulfide bridge in spinach chloroplast fructose‐1,6‐bisphosphatase

FEBS Letters

Häberlein, Ingo¹  Drescher, Dorothee F¹  Follmann, Hartmut¹ 

[1] University of Kassel, Department of Biochemistry, Heinrich-Plett-Str. 40, D-34109 Kassel, Germany

关键词: Thioredoxin;    Sulfitolysis;    Fructose-1;    6-bisphosphatase;    Protein-protein complex;    Disulfide bridge;    Spinacia oleracea;    FbPase;    fructose-1;    6-bisphosphatase;    mBB;    monobromobimane;    TRf and TRm;    thioredoxin species from spinach chloroplasts;    DTT;    dithiothreitol;   

DOI  :  10.1016/S0014-5793(98)00150-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A significant difference between cytosolic and chloroplastic fructose-1,6-bisphosphatase (FbPase) is an extra peptide in the middle of chloroplast FbPase which contains three additional cysteine residues. Sit-directed mutagenesis experiments have shown that at least two of these cysteine residues are involved in forming the regulatory disulfide bridge [Jacquot, J.-P. et al., FEBS Lett. 401 (1997) 143–147] which is the presupposition for the thioredoxin-dependent control of chloroplast FbPase activity. Here we report that each subunit of the FbPase contains an additional structural disulfide bridge which has been observed by combined application of thioredoxins and sulfitolysis. Observation of the structural disulfide bridges by sulfitolysis was only possible when the FbPase was already specifically reduced by the homologous thioredoxin species TR_m and TR_f from spinach chloroplasts. Interestingly, the accessibility of the structural disulfide bridge for sulfite ions depends on the thioredoxin species engaged in the thioredoxin/FbPase complex.

【 授权许可】

Unknown