LIVF17 P19 QEK21 GSA25 PKA54 YFWL64 DEN67 H69 HN70 WLFIYV100 LMIVF103 GN116 P125 LMIVF131 YFHW136 LIVFM139 FYL156 FLYIV159 WF161 FYWLV164 GA199 # found 21 key residues