0 ▁Asian ▁Games ▁Category : 2 0 1 9 ▁A FC ▁Asian ▁Cup ▁players ▁Category : Associ ation ▁football ▁mid field ers ▁Category : As ian ▁Games ▁compet itors ▁for ▁China <0x0A> </s> ▁The ▁fragment ▁cry st all izable ▁region ▁( F c ▁region ) ▁is ▁the ▁tail ▁region ▁of ▁an ▁ant ib ody ▁that ▁interact s ▁with ▁cell ▁surface ▁re cept ors ▁called ▁F c ▁re cept ors ▁and ▁some ▁prote ins ▁of ▁the ▁complement ▁system . ▁This ▁property ▁allows ▁ant ib od ies ▁to ▁activ ate ▁the ▁imm une ▁system . ▁In ▁Ig G , ▁Ig A ▁and ▁Ig D ▁ant ib ody ▁is ot ypes , ▁the ▁F c ▁region ▁is ▁composed ▁of ▁two ▁identical ▁protein ▁fragments , ▁derived ▁from ▁the ▁second ▁and ▁third ▁constant ▁domains ▁of ▁the ▁ant ib ody ' s ▁two ▁heavy ▁ch ains ; ▁Ig M ▁and ▁Ig E ▁F c ▁regions ▁contain ▁three ▁heavy ▁chain ▁constant ▁domains ▁( CH ▁domains ▁ 2 – 4 ) ▁in ▁each ▁pol ype pt ide ▁chain . ▁The ▁F c ▁regions ▁of ▁Ig G s ▁bear ▁a ▁highly ▁conser ved ▁N - gly cos yl ation ▁site . ▁G ly cos yl ation ▁of ▁the ▁F c ▁fragment ▁is ▁essential ▁for ▁F c ▁re ceptor - medi ated ▁activity . ▁The ▁N - gly c ans ▁attached ▁to ▁this ▁site ▁are ▁pre domin antly ▁core - f uc os yl ated ▁di ant enn ary ▁structures ▁of ▁the ▁complex ▁type . ▁In ▁addition , ▁small ▁amounts ▁of ▁these ▁N