谷物中生物活性脂多糖的定量分析研究

Studies on Quantitative Determination of Biologically Active Lipopolysaccharide in Cereal

研究发现被谷物脂多糖激活的东方鲎变形细胞溶解物，具有水解Ｂｚ－Ｖａｌ－Ｇｌｙ－Ａｒｇ－ＰＮＡ，Ｂｏｃ－Ｌｅｕ－Ｇｌｙ－Ａｒｇ－ＰＮＡ和Ｂｏｃ－Ｖａｌ－Ｌｅｕ－Ｇｌｙ－Ａｒｇ－ＰＮＡ等对硝基苯胺肽类底物的酰胺酶活性，这些肽类底物的羧基端都为Ｇｌｙ－Ａｒｇ顺序。利用东方鲎变形细胞溶解物和Ｂｚ－Ｖａｌ－Ｇｌｙ－Ａｒｇ－ＰＮＡ底物，建立了定量分析谷物及其产品中脂多糖的方法。分析结果表明，米粉和米糠的脂多糖含量高于面粉和麸皮的含量。

Amebocyte lysate from Tachypleus tridentatus activated by cereal lipopolysaccharide was found to hydrolyze Bz-Val-Gly-Arg-p-nitroanilide(PNA),Boc-Leu-Gly-Arg-PNA,and Boc-Val-Leu-Gly-Arg-PNA,all of which have the COOH-terminal Gly-Arg sequence.This amidase activity was due to a clotting enzyme contained in the lysate.Furthermore,the amidase activity increased with the increasing the concentration of the lipopolysaccharide added to the lysate.A method has been developed to determine lipopolysaccharide quantitatively in cereal and its products,using Tachypleus lysate and Bz-Val-Gly-Arg-PNA.The lipopolysaccharide content of rice flour and rice bran was higher than that of wheat flour and wheat bran.