Evidence for two calcium transport systems in the photosynthetic bacterium Chromatium vinosum

FEBS Letters

Cobb, Andrea D.¹  Knaff, David B.¹  Smith, James A.¹  Peach, Cindy R.¹ 

[1] Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA

关键词: Ca2+ transport;    La3+;    Ruthenium red;    (C. vinosum);    BChl;    bacteriochlorophyll;    CCCP;    carbonyl cyanide-m-chlorophenylhydrazone;    DCCD;    N;    N'-dicyclohexylcarbodiimide;    DMSO;    dimethyl sulfoxide;   

DOI  :  10.1016/0014-5793(86)81158-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Light-dependent Ca²⁺ efflux via the Ca²⁺/H⁺ antiport in the photosynthetic purple sulfur bacterium Chromatium vinosum was inhibited by three phenothiazines: chlorpromazine; trifluoperazine and phenothiazine. The inhibitors had no effect on Ca²⁺ uptake by C. vinosum in the dark nor any effect on the light-dependent efflux of either Na⁺ or Tl⁺ catalyzed, respectively, by the C. vinosum Na⁺/H⁺ or K⁺/H⁺ antiports. Ruthenium red and LaCl₃, neither of which inhibited light-dependent Ca²⁺ efflux in C. vinosum, markedly inhibited Ca²⁺ uptake in the dark by C. vinosum cells. Ruthenium red had no effect on the uptake of either Na⁺or the K⁺ analog T1⁺ by C. vinosum cells in the dark. These results have been interpreted in terms of two separate Ca²⁺ transport systems in C. vinosum: (i) a phenothiazine-sensitive and ruthenium red, La³⁺-insensitive Ca²⁺/H⁺ antiport responsible for Ca²⁺ efflux in the light; and (ii) a ruthenium red and La³⁺-sensitive but phenothiazine-insensitive Ca²⁺ uptake system.

【 授权许可】

Unknown