LIVF17 P19 QE21 YFWLV64 DE67 H69 HN70 LMIVF103 G116 P125 LMIVF131 DNESG134 YFWL136 LIVFM139 YFL156 FLYIV159 WFY161 FYWLV164 G199 WYFL200 # found 20 key residues