The technique of the reverse-phase performance liquid chromatography (RP-HPLC) was employed to separate and purify the toxic proteins from the venom of Agkistrodon blomhoffii brevicaudus collected in China 3 toxic pro...The technique of the reverse-phase performance liquid chromatography (RP-HPLC) was employed to separate and purify the toxic proteins from the venom of Agkistrodon blomhoffii brevicaudus collected in China 3 toxic proteins marked as AgTx-1, AgTx-2 and AgTx-3 consisting of about 122 amino acid residues were screened The toxicities (LD50,) of the AgTx-1, AgTx-2 and AgTx-3 were 0.075, 0.51 and 6.6 mg per kg weight of mice respectively. Toxicological experiment in the chick biventer cervicis nerve-muscle preparation showed that the acetylcholine (Ach) sensitivity of the preparation was unchanged after the total failure of the indirect contraction caused by AgTx-1 and AgTx-2. suggesting that they were presynaptic blockers, namely β-type of snake toxins. However, the amplitude of indirect contraction of the preparation was gradually reduced due to its incomplete relaxation caused by AgTx-3, indicating that it should belong to the category of cytotoxins. The partial amino acid sequences of 3 toxins have been established. It was found in ref. [1] that the sequences of the first 32 N-terminal ammo acid residues of AgTx-1 and AgTx-2, as well as β -agkistrodotoxin (β-AgTx) reported previously were identical (the residue at the position 30 of β-AgTx should be Trp). In view of the similarity in toxicities, and the amounts in the venom and other properties, it was concluded that AgTx-1 should be β-AgTx and consequently was renamed β1-AgTx. AgTx-2 should be the isoform of β1-AgTx, and correspondingly named β2-AgTx.展开更多
基金Project supported in part by the Grant-in-Aid for Overseas Scientific Research from the Ministry of Education,Science and Culture. Japan
文摘The technique of the reverse-phase performance liquid chromatography (RP-HPLC) was employed to separate and purify the toxic proteins from the venom of Agkistrodon blomhoffii brevicaudus collected in China 3 toxic proteins marked as AgTx-1, AgTx-2 and AgTx-3 consisting of about 122 amino acid residues were screened The toxicities (LD50,) of the AgTx-1, AgTx-2 and AgTx-3 were 0.075, 0.51 and 6.6 mg per kg weight of mice respectively. Toxicological experiment in the chick biventer cervicis nerve-muscle preparation showed that the acetylcholine (Ach) sensitivity of the preparation was unchanged after the total failure of the indirect contraction caused by AgTx-1 and AgTx-2. suggesting that they were presynaptic blockers, namely β-type of snake toxins. However, the amplitude of indirect contraction of the preparation was gradually reduced due to its incomplete relaxation caused by AgTx-3, indicating that it should belong to the category of cytotoxins. The partial amino acid sequences of 3 toxins have been established. It was found in ref. [1] that the sequences of the first 32 N-terminal ammo acid residues of AgTx-1 and AgTx-2, as well as β -agkistrodotoxin (β-AgTx) reported previously were identical (the residue at the position 30 of β-AgTx should be Trp). In view of the similarity in toxicities, and the amounts in the venom and other properties, it was concluded that AgTx-1 should be β-AgTx and consequently was renamed β1-AgTx. AgTx-2 should be the isoform of β1-AgTx, and correspondingly named β2-AgTx.
