Formulation: A solid
Formal Name: D-phenylalanyl-L-cysteinyl-L-tyrosyl-D-tryptophyl-L-ornithyl-L-threonyl-3-mercapto-L-valyl-L-threoninamide-cyclic (2→7)-disulfide, trifluoroacetate salt
Purity: ≥98%
Formula Markup: C50H67N11O11S2• XCF3COOH
Formula Weight: 1062,3
Shelf life (days): 1460
Notes: CTOP is a peptide antagonist of the μ-opioid receptor (IC50 = 2.8 nM).{23794} It is selective for μ-opioid receptors over δ-opioid receptors (IC50 = 13,500 nM) and somatostatin receptors (IC50 = 24,000 nM). CTOP inhibits the antinociceptive effect of morphine in the tail flick test in mice (ED50 = 0.018 nmol) and reverses morphine-induced increases in locomotor activity (ED50 = 0.02 nmol).{47504} It also induces withdrawal symptoms in a mouse model of chronic, but not acute, morphine dependence.