CAJ | 학술논문

从大理石芋螺毒液中分离得到一种新型的含有D型氨基酸,并属于M超家族的芋螺毒素--芋螺马芬.应用2D NMR方法测定了芋螺马芬在pH 5条件下的三维结构,由205个距离约束,8个二面角约束以及两个氢键约束得到了20个最优结构.它们骨架原子的均方根偏差为(0.074±0.029)nm.芋螺马芬在pH 5条件下的二级结构是位于C端的一个短的310螺旋,同时在Ala6附近呈一个较为松散的环状区域.将芋螺马芬在pH 5以及pH 3条件下的溶液结构以及表面电荷进行了比较.尽管芋螺马芬在pH 5条件下的溶液结构与在pH 3条件下的相比,在C端有一个相似的二级结构单元,但是整体的骨架结构截然不同,在pH 5条件下,芋螺马芬的表面结构从正面看起来像一个"曲臂".结构的差异揭示了芋螺马芬对pH相当敏感,预示着它在体内的活性可能与酸度密切相关.
종대리석우라독액중분리득도일충신형적함유D형안기산,병속우M초가족적우라독소--우라마분.응용2D NMR방법측정료우라마분재pH 5조건하적삼유결구,유205개거리약속,8개이면각약속이급량개경건약속득도료20개최우결구.타문골가원자적균방근편차위(0.074±0.029)nm.우라마분재pH 5조건하적이급결구시위우C단적일개단적310라선,동시재Ala6부근정일개교위송산적배상구역.장우라마분재pH 5이급pH 3조건하적용액결구이급표면전하진행료비교.진관우라마분재pH 5조건하적용액결구여재pH 3조건하적상비,재C단유일개상사적이급결구단원,단시정체적골가결구절연불동,재pH 5조건하,우라마분적표면결구종정면간기래상일개"곡비".결구적차이게시료우라마분대pH상당민감,예시착타재체내적활성가능여산도밀절상관.
Conomarphin, a novel conopeptide containing D-amino acid, was identified from the venom of Conus marmoreus and classified into M-superfamily of conotoxin. In this article, we reported the 3D structure of conomarphin at pH 5 determined using 2D 1H NMR method in aqueous solution. Twenty converged structures of this peptide were obtained based on 205 distance constraints, 8 dihedral angle constraints, and 2 hydrogen bond constraints. The root mean square deviation (RMSD) values of the backbone atoms were (0.074±0.029) nm. The refined structure of conomarphin at pH 5 contained a short 310-helix at C-terminal of the peptide. It was also characterized by a loose loop centered at Ala6. Comparison of structural and electrostatic potential between conomarphin at pH 3 and pH 5 were presented. Although the solution structure of conomarphin at pH 5 shared part of the same secondary structure element with the structure of conomarphin at pH 3, it adopted a distinctive backbone conformation with the overall molecule resembling a "flexcual arm" when viewed from the front. Structural differences imply that this conopeptide is rather pH sensitive and its bioactivity in vivo might be related to the acidity.