The present invention provides peptides comprising a sequence of X-6X-5X-4X-3X-2X-1X1PX3X4PX6X7P-GX10X11AX13X14X15X16LX18X19X20X21X22X23LX25X26YLX29X30X31X32 wherein the amino acids X-6, X-5, X-4X-3, X-2, X-1, X1, X3, X4, X6, X7, X10, X11, X13, X14, X15, X16, X18, X19, X20, X21, X22, X25, X26, X29, X30, X31, and X32 are as defined herein. The present invention further provides pharmaceutical compositions comprising the peptides and methods of using the peptides. Also provided are methods of screening a library of peptide dimers using a peptide dimer display technology.