Conservative substitutions include for example, replacement of glycine for {HEAD ~ alanine}, valine for isoleucine, leucine for isoleucine, aspartic acid for glutamic acid, lysine for arginine, asparagine for glutamine, phenylalanine for {TAIL ~ tryptophan}, and tryptophan for tyrosine 
Conservative substitutions include for example , replacement of glycine for { HEAD ~ alanine } , valine for isoleucine , leucine for isoleucine , aspartic acid for glutamic acid , lysine for arginine , asparagine for glutamine , phenylalanine for { TAIL ~ tryptophan } , and tryptophan for tyrosine
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH