Novel, cell-permeable inhibitor of protein kinase Mζ (PKMζ), a constitutively active, atypical PKC isozyme involved in LTP maintenance. Selectively blocks PKMζ-induced synaptic potentiation in hippocampal slices in vitro. Reverses late-phase LTP (IC50 = 1 - 2.5 μM) and produces persistent loss of 1-day-old spatial memory following central administration in vivo. Control Peptide and Biotinylated Peptide also available.. MW (observed): 1928.4.