Caldwell J E, Abildgaard F, Dzakula Z, Ming D, Hellekant G, Markley J L
Graduate Program in Biophysics, University of Wisconsin-Madison 53706, USA.
Nat Struct Biol. 1998 Jun;5(6):427-31. doi: 10.1038/nsb0698-427.
The fruit of Pentadiplandra brazzeana Baillon contains a small, sweet-tasting protein named brazzein. The structure of brazzein in solution was determined by proton nuclear magnetic resonance spectroscopy at pH 5.2 and 22 degrees C. The brazzein fold, which contains one alpha-helix and three strands of antiparallel beta-sheet, does not resemble that of either of the other two sweet-tasting proteins with known structures, monellin and thaumatin. Instead, the structure of brazzein resembles those of plant gamma-thionins and defensins and arthropod toxins. Sequence comparisons predict that members of a newly-identified family of serine proteinase inhibitors share the brazzein fold.
布拉齐甜蛋白（Pentadiplandra brazzeana Baillon）的果实含有一种名为布拉齐因（brazzein）的小的、甜味蛋白质。通过在pH 5.2和22摄氏度下的质子核磁共振光谱法确定了溶液中布拉齐因的结构。布拉齐因的折叠结构包含一个α-螺旋和三条反平行β-折叠链，与另外两种已知结构的甜味蛋白质莫内林（monellin）和索马甜蛋白（thaumatin）的折叠结构均不相似。相反，布拉齐因的结构类似于植物γ-硫堇蛋白和防御素以及节肢动物毒素的结构。序列比较预测，新鉴定的丝氨酸蛋白酶抑制剂家族成员具有布拉齐因的折叠结构。
