title: Chemical modification of alpha-bungarotoxin with bifunctional reagent, 1,5-difluoro-2,4-dinitrobenzene.
abstract: alpha-Bungarotoxin (alpha-BuTX) was modified with a bifunctional reagent, 1,5-difluoro-2,4-dinitrobenzene (DFDNB) to prepare the cross-linked derivatives. The modified products, obtained from the reaction at pH 8.5 with a 2-fold molar excess of DFDNB, were purified successively on a Sephadex G-50 and a SP-Sephadex C-25 columns, and, fast protein liquid chromatography (FPLC) on a Mono S column. The preparation was proved to be a homogeneous and dimeric form which arose from the intermolecular cross-linkage of alpha-BuTX through a dinitrophenylene (DPE) group. The cross-linked alpha-BuTX derivative still retained approximately 50% residual lethality and 70% residual binding activity to nicotinic acetylcholine receptor (nAChR). The modified derivative also showed relatively high antigenic activity toward anti-alpha-BuTX antibody as measured by competitive radioimmunoassay (RIA).
authors.affiliation: Department of Biochemistry, Kaohsiung Medical College, Taiwan, Republic of China.
authors.forename: M L
authors.initials: ML
authors.lastname: Yang
authors.forename: C C
authors.initials: CC
authors.lastname: Chang
mesh_terms: D000818:Animals; D002038:Bungarotoxins / Q000276:immunology / Q000378:metabolism* / Q000633:toxicity; D003432:Cross-Linking Reagents; D004139:Dinitrofluorobenzene / Q000031:analogs & derivatives; D005260:Female; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D011817:Rabbits; D013329:Structure-Activity Relationship
chemical_list: D002038:Bungarotoxins; D003432:Cross-Linking Reagents; D004139:Dinitrofluorobenzene; C002041:1,5-difluoro-2,4-dinitrobenzene