| abstract |
An α-helical polypeptide suitable for activating or inhibiting cell death of formula (I): ** Formula ** in which: each R1 and R2 are independently H, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl , arylalkyl, cycloalkylalkyl, heteroarylalkyl or heterocyclylalkyl; R3 is a crosslinker that is C1-C20 alkyl, C2-C20 alkenyl or C2-C20 alkynyl; where R3 is substituted with 0 to 6 R5; R5 is halogen, alkyl, OR6, N (R6) 2, SR6, SOR6, SO2R6, CO2R6, R6, an epoxide, a fluorescent moiety or a radioisotope; R6 is H, alkyl or a therapeutic agent; x is an integer selected from 2, 3 or 6; each y is independently an integer from 0 to 100; z is an integer from 1 to 10; and each Xaa is independently an alpha-amino acid; and wherein the polypeptide is transported or actively transported through the cell membrane, as determined in an assay comprising preparing a fluorescently labeled polypeptide, applying the fluorescently labeled polypeptide to an intact cell and testing the cell in as for cell fluorescence by microscopy or high performance cell fluorescence detection. |