• 作者： 張均昌; 林乾喻
• 作者服務機構： 私立高雄醫學院生物化學科
• 中文摘要： 從雨傘節(Bungarus multicinctus)毒分離出來的β-Bungarotoxin (β-Bgt),分子中唯一色胺酸(Tryptophan)與5個
  組織胺酸(Histidine)中的一個殘基，分別以2-Hydroxy-5-nitrobenzyl bromide (HNB-Br)及p-Bromophenacyl bromide
  (PBP-Br）修飾時，磷脂?A活性與致死毒性均顯著下降，但抗原性並不受影響，表示β-Bgt分子中唯一色胺酸與其中
  之一組織胺酸殘基，可能與磷脂?A活性及致死毒性有密切關係，而與抗原決定基無關。
  色胺酸修飾毒素(HNB-0 1-Bgt），因致死毒性極低，為一良好之免疫原，免疫家兔時可產生極高力價之抗β-Bgt血清
  抗體含量可達8.1 mg/ml且同時它可中和極高之β-Bgt及雨傘節毒之致死毒性。
  測定單價抗體Fab與β-Bgt反應形成之可溶性複合物之分子量結果，得知β-Bgt分子中具有四個抗原基。
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• 英文摘要： The tryptophan and histidine residues in β-bungarotoxin isolated from the venom of Bungarusmulticinctus were subjected to chemical modification. Both phospholipase A activity and lethal toxicityof β-bungarotoxin were markedly decreased as the single tryptophan and one out of the five histidineresidues were modified with 2-hydroxy-5-nitrobenzyl bromide and p-bromophenacyl bromide, respectively.The antigenic activity of modified derivatives, however, remained virtually unchanged, indicating that bothamino acid residues might not be closely related to the antigenic sites of the toxin. The less toxic tryptophan-modified derivative, 2-hydroxy-5-nitrobenzyl-β-bungarotoxin, could beused as a good immunogen for the production of high content (8.1 mg per ml) of precipitating antibodyagainst the native toxin in the rabbits. The antisera not only could neutralize the lethal toxicity of nativetoxin but also that of crude Bungarus multicinctus venom to high extent. An estimate of the molecular weight of soluble complex formed from Fab with β-bungarotoxinindicates that β-bungarotoxin exhibits four antigenic sites per molecule.
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