wherein Asn and His represent an asparagine residue and a histidine residue, respectively, and X represents {TAIL ~ a hydrogen atom} or {HEAD ~ a sugar chain}, and A and B each represent independently a hydrogen atom or an amino acid residue 
wherein Asn and His represent an asparagine residue and a histidine residue , respectively , and X represents { TAIL ~ a hydrogen atom } or { HEAD ~ a sugar chain } , and A and B each represent independently a hydrogen atom or an amino acid residue
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH