Tacrolimus,current lot 99.9% pure, by FermentekTacrolimus is 23-membered macrolide lactone discovered in 1984, by Kino T, Hatanaka H and Hashimoto M. [reference 2]Tacrolimus exhibits potent inhibitory effect on T- lymphocyte activation. It binds to immunophilins FK506 binding proteins (FKBP-12) and a complex of FKBP-12, calcium, calmodulin and calcineurin is formed, inhibiting phosphatase activity of calcineurin. This prevents dephosphorylation and translocation of nuclear factor of activated T cells (NF-AT) and inhibits transcription of early T-cell activation gene, Interleukin-2, Tumour Necrosis Factor (TNF-a) and proto-oncogenes; suppressing expression of IL-2 and IL-7 receptor. This results in inhibition of T-lymphocyte activation. Tacrolimus also inhibits the mixed lymphocyte reaction, generation of cytotoxic T-cells and T-cell dependent B-cell activation.[reference 1] 7AAD 17AA 17DMAG A23187 Actinomycin Aflatoxin B1 Aflatoxin B2 Aflatoxin M1 Alamethicin Anisomycin Apicidin Aphidicolin Ascomycin Bafilomycin Brefeldin Castanospermine Cerulenin Chelerythrine Chromomycin A3 Citrinin Cyclopamine Cytochalasin A Cytochalasin B Cytochalasin C Cytochalasin D Cytochalasin E Dihidrocytochalasin Deoxynivalenol Diacetoxyscirpenol FK506 Forskolin Fumagillin Fumonisin B1 Fumonisin B2 Geldanamycin Genistein Gliotoxin Hypericin HT2 toxin Ionomycin Ca K252A K252B KT5720 KT5823 Leptomycin B Mithramycin A Mitomycin C Moniliformin Mycophenolic Myriocin Nigericin Nonactin Ochratoxin A Oligomycin Parthenolide Patulin Paxilline Penicillic acid Penitrem PKC412 Puromycin Puromycin AN Radicicol Rapamycin Staurosporine Sirolimus Sterigmatocystin T2 toxin Taxol tetnoxin Thapsigargin Thiolutin Thiostrepton Triacsin Trichostatin Tunicamycin Valinomycin Verruculogen Vomitoxin Withaferin A Wortmannin Zearalenone Tacrolimus: Definition from Answers.