Tai S S, Wu L S, Chen E C, Tzen J T
Graduate Institute of Agricultural Biotechnology, National Chung-Hsing University, Taichung, Taiwan 40227 ROC.
J Agric Food Chem. 1999 Dec;47(12):4932-8. doi: 10.1021/jf990366z.
Insoluble 11S globulin and soluble 2S albumin, conventionally termed alpha-globulin and beta-globulin, are the two major storage proteins and constitute 80-90% of total seed proteins in sesame. Two full-length cDNA clones were sequenced and deduced to encode sesame 11S globulin and 2S albumin precursors, respectively. Deduced amino acid composition reveals that 2S albumin, but not 11S globulin, is a sulfur-rich protein. Three abundant polypeptides of 50-60 kDa were resolved on SDS-PAGE when seed-purified 11S globulin was prepared in nonreducing conditions. Immunological analysis suggests that these three polypeptides are encoded by homologous genes. Immunodetection on the overexpressed protein of the 11S globulin clone in Escherichia coli indicates that this clone encodes the precursor protein of one of the three purified 11S globulin polypeptides.
不溶性11S球蛋白和可溶性2S白蛋白，传统上称为α-球蛋白和β-球蛋白，是芝麻中的两种主要贮藏蛋白，占芝麻种子总蛋白的80-90%。对两个全长cDNA克隆进行了测序，推断它们分别编码芝麻11S球蛋白和2S白蛋白前体。推导的氨基酸组成表明，2S白蛋白是一种富含硫的蛋白质，而11S球蛋白不是。在非还原条件下制备种子纯化的11S球蛋白时，在SDS-PAGE上分离出三种50-60 kDa的丰富多肽。免疫分析表明，这三种多肽由同源基因编码。对大肠杆菌中11S球蛋白克隆的过表达蛋白进行免疫检测表明，该克隆编码三种纯化的11S球蛋白多肽之一的前体蛋白。
