Its action site is located on the postsynaptic membrane and the biological activity of hwtx - i is located in the fifth p - turn containing lys25 and lys 27 . to - conotoxin mviia is a neurotoxin belonging to one of n - type ca2 + channels inhibitors , purified from the venom of the conus marine snails , contains 25 amino acid residues with three disulfide binds . it adopts the pattern of ick and its linkage of the disulfide binds and space conformation are highly similar to hwtx - i -芋螺毒素mviia ( - conotoxinmviia )是從芋螺屬( conus )海底蝸牛毒液中分離提純的一種活性多肽,屬于n -型ca ~ ( 2 + )通道阻斷劑中一種,含25個(gè)氨基酸殘基,三對(duì)二硫鍵,其二硫鍵連接方式、分子的空間構(gòu)象與hwtx -很相似,采取ick結(jié)構(gòu)模體。