In certain embodiments, {HEAD ~ X4} is selected from D proline, {TAIL ~ D arginine} and D phenylalanine 
In certain embodiments , { HEAD ~ X4 } is selected from D proline , { TAIL ~ D arginine } and D phenylalanine
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH