Liu X, Maeda S, Hu Z, Aiuchi T, Nakaya K, Kurihara Y
Department of Chemistry, Faculty of Education, Yokohama National University, Japan.
Eur J Biochem. 1993 Jan 15;211(1-2):281-7. doi: 10.1111/j.1432-1033.1993.tb19896.x.
A new sweet protein, named mabinlin II, was extracted with 0.5 M NaCl solution from the seeds of Capparis masaikai Lévl. and purified by ammonium sulfate fractionation, carboxymethylcellulose-Sepharose ion-exchange chromatography and gel filtration. The sweetness of mabinlin II was unchanged by at least 48 h incubation at nearly boiling temperature. Purified mabinlin II thus obtained gave a single band having a molecular mass of 14 kDa on SDS/PAGE. In the presence of dithiothreitol, mabinlin II gave two bands having molecular masses of 4.6 kDa and 5.2 kDa on SDS/PAGE. Two peptides (A chain and B chain) were separated from reduced and S-carboxamidomethylated mabinlin II by HPLC. The amino acid sequences of the A chain and B chain were determined by the automatic Edman-degradation method. The A chain and B chain consist of 33-amino-acid and 72-amino-acid residues, respectively. The A chain is mostly composed of hydrophilic amino acid residues and the B chain also contains many hydrophilic residues. High similarity was found between the amino acid sequences of mabinlin II and 2S seed storage proteins, especially 2S albumin AT2S3 in Arabidopsis thaliana (mouse-ear cress).
一种名为马槟榔 II 的新型甜味蛋白，用 0.5 M NaCl 溶液从马槟榔种子中提取，并通过硫酸铵分级沉淀、羧甲基纤维素 - 琼脂糖离子交换色谱和凝胶过滤进行纯化。马槟榔 II 在接近沸腾的温度下孵育至少 48 小时后甜度不变。如此获得的纯化马槟榔 II 在 SDS/PAGE 上呈现出一条分子量为 14 kDa 的单一带。在二硫苏糖醇存在下，马槟榔 II 在 SDS/PAGE 上呈现出两条分子量分别为 4.6 kDa 和 5.2 kDa 的带。通过 HPLC 从还原和 S - 羧甲基化的马槟榔 II 中分离出两条肽链（A 链和 B 链）。A 链和 B 链的氨基酸序列通过自动 Edman 降解法测定。A 链和 B 链分别由 33 个氨基酸残基和 72 个氨基酸残基组成。A 链主要由亲水性氨基酸残基组成，B 链也含有许多亲水性残基。发现马槟榔 II 的氨基酸序列与 2S 种子贮藏蛋白，特别是拟南芥（鼠耳芥）中的 2S 清蛋白 AT2S3 之间具有高度相似性。
