Characterization of the calcium‐binding sites of calcineurin B
- 27 March 1995
- journal article
- Published by Wiley in FEBS Letters
- Vol. 362 (1), 55-58
- https://doi.org/10.1016/0014-5793(95)00207-p
Abstract
Calcineurin (CaN) is a calcium- and calmodulin-dependent serine/threonine phosphatase whose inhibition by the immunosuppressant-immunophilin complexes (cyclosporin-cyclophilin and FK506-FKBP) is considered key to the mechanism of immunosuppression. CaN is a heterodimer, consisting of a 59 kDa catalytic subunit (A) and a 19 kDa calcium-binding regulatory subunit (B). The latter is postulated to harbor four calcium binding domains of the EF hand type. The titration of the CaN B apoprotein with the isomorphic Cd2+ was followed by 113Cd NMR and these data support one high-affinity metal binding site and three lower-affinity ones. Flow dialysis data with Ca2+ indicate one high affinity calcium binding site with Kd ∼ 2.4 × 10−8 M and three other sites with Kd ∼ 1.5 × 10−5 M. The chemical shifts of all four 113Cd resonances (−75, −93, −106 and −119 ppm) are in the same range as found in other 113Cd substituted calcium-binding proteins, and are indicative of all-oxygen coordination of pentagonal bipyramidal geometryKeywords
This publication has 35 references indexed in Scilit:
- Dual Calcium Ion Regulation of Calcineurin by Calmodulin and Calcineurin BBiochemistry, 1994
- 15N NMR assignments of (Cd2+,)2-calbindin D9k and comparison with (Ca2+)2-calbindin D9k. Cadmium as a substitute for calcium in calcium-binding proteinsMagnetic Resonance in Chemistry, 1993
- 113Cd NMR relaxation study of the protein calbindin D9KJournal of Magnetic Resonance (1969), 1992
- Inhibition of calcineurin by cyclosporin A‐cyclophilin requires calcineurin BFEBS Letters, 1992
- The mechanism of action of cyclosporin A and FK506Immunology Today, 1992
- 113Cd-NMR evidence for cooperative interaction between amino- and carboxyl-terminal domains of calmodulinBiochemical and Biophysical Research Communications, 1989
- Structure of calmodulin refined at 2.2 Å resolutionJournal of Molecular Biology, 1988
- Common structural framework of the two calcium/magnesium binding loops of troponin C and other calcium binding proteinsBiochemistry, 1985
- Calcium and Cadmium Binding to Troponin CEuropean Journal of Biochemistry, 1983
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976