摘要
禾本科小麦和水稻等作物种子中由于缺乏赖氨酸(Lys)等必需氨基酸而降低了蛋白质品质。本研究广泛收集了禾本科以外的种子,经氨基酸组分分析,筛选出3个赖氨酸(Lys)含量在6.7％以上的植物种。以其中一个富含7.9％Lys.的植物为材料,用改良的IEF和SDS电泳方法纯化出31种蛋白质,其中一种pI6.1-18kD蛋白质的Lys含量为11.4％,并富含苏氨酸、缬氨酸、异亮氨酸等必需氨基酸。编码此蛋白质的基因可作为改良谷类作物的极好基因源。
The nutritional quality of seed proteins from cereals, such as wheat and rice, is compara- tively low due to its deficency in lysine and some essential amino acids. In this research ex- tensive varieties of plant seed samples were collected and screened by analysis of amino acid co- mposition. Three lysing-rich species which contain more than 6.7% of lysine in total seed pro- teins were found. 31 kinds of proteins were purified from a species which contains 7.9% of lysine using the modified methods of IEF and SDS electrophoresis. One protein with PI 6.1 and 18 kD was identified which contains 11.4% of lysine and was rich in threonine, valine and isoleucine. This is the first example of the protein which could complement several limi- ting amino acids of wheat or rice. Further research on the structural gene encoding this pro- tein would have great potential value for improvement of protein quality of thtse cereals.
