PUTATIVE CYTOPLASMIC AMPHIPHILIC DOMAINS IN THE NERVE GROWTH-FACTOR TUMOR-NECROSIS-FACTOR RECEPTOR SUPERFAMILY

Potential cu-helical regions in cytoplasmic domains of the NGF/TNF rec eptor superfamily were searched to identify amphiphilic sequences favo uring association with membrane surfaces, analogous to the predicted s econdary structure of mastoparan (MP). Similar to MP, NGFP (rat, chick , human), human TNFR-1, and human 4-1BB have domains with putative sur face membrane associating sequences. The circular dichroism spectra of mastoparan and a peptide homologous to the putative amphiphilic domai n of NGFR were identical in an aqueous milieu, and both adopted an alp ha-helical conformation in trifluoroethanol.