In {TAIL ~ other embodiments}, X5 is selected from {HEAD ~ a neutral D amino acid} and a positively charged D amino acid 
In { TAIL ~ other embodiments } , X5 is selected from { HEAD ~ a neutral D amino acid } and a positively charged D amino acid
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH