M.W. 804.03

C44H69NO12

[104987-11-3] RTECS: KD4200000

M.I. 13: 9117

Storage:  Store at or below -20 ºC.  Solubility:  Soluble in DMSO or ethanol; store solution at or below -20 ºC.  Disposal:  A

FK-506 is a potent immunosuppresant and in vitro T cell proliferation blocker.  It has been shown to disrupt calcineurin (also known as CaN or phosphatase 2B)-mediated signal transduction in T lymphocytes.  The compound interacts with its FK506-binding protein-12 (FKBP12).  The resulting complex, in turn, interferes with calcineurin substrate interaction.  Dumont, F.J. "FK506, an immunosuppressant targeting calcineurin function." Curr. Med. Chem. 7: 731-748 (2000).

FK-506 inhibits FKBP activity resulting in an increase in the release of sarcoplasmic reticulum-derived calcium.  FK-506 also appears to inhibit Na(+)-Ca2+ exchange.  Prolonged exposure of Xenopus A6 cells to FK-506 significantly inhibits aldosterone-stimulated Na+ transport and Na(+)-K(+)-ATPase activity.  Unlike rapamycin, which also binds to FK506-binding protein-12, FKBP12 with or without bound FK506 has no effect on rat brain PKC activity in vitro.  McCall, E., et al "Effects of FK-506 on contraction and Ca2+ transients in rat cardiac myocytes." Circ. Res. 79: 1110-1121 (1996).  Rokaw, M.D., et al "FK-506 and rapamycin but not cyclosporin inhibit aldosterone-stimulated sodium transport in A6 cells" Am. J. Physiol. 271: C194-202 (1996).  Rokaw, M.D., et al "Rapamycin inhibits protein kinase C activity and stimulates Na+ transport in A6 cells; J. Biol. Chem. 271: 32468-32473 (1996).

FK-506 is subject to various Fujisawa Co. patents in the U. S. and other countries.  Not available in some countries; not available to some institutions; cannot be sold for some uses.

See also our other standard immunosuppressant products: C-6000   Cyclosporin A R-5000   Rapamycin