二苯乙内酰脲

P28 紫色 Formation of a peptide bond 肽键形成–4侧链具有的反应–形成二硫键-其它反应 Tyr,His,Arg Review Isoelectric Point Titration滴定 of an amino acid 滴定 Gly幻灯片 18 His Lys Glu Reaction of amino acids Section 4 Protein isolation and purification 蛋白质分离及提纯 Working With Proteins Experimental techniques for protein analysis and characterization Purification steps A cell contains many types of proteins In the lab we want to isolate a single protein for experiments Purification steps We first grow cells or isolate tissues that contain the protein of interest We break open the cells to produce a crude extract Use centrifugation离心 to separate soluble from insoluble material We fractionate 分离 the protein mixture based on properties of such as size, charge affinity or solubility.

丹磺酰氯与氨基酸反应生成荧光性质强和稳定的磺胺衍生物，用于多肽链NH 用于多肽链 3末端氨基酸的标记烃基化反应(1) 2，4-二硝基氟苯2，4-dinitrofluorobenzene，二硝基氟苯(二硝基氟苯 DNFB也叫做试剂。DNFB在弱碱性溶液也叫做Sanger试剂试剂中与氨基酸发生取代反应，生成黄色化合物二硝基二硝基苯基氨基酸(dinitro phenyl amino acid， DNP氨基酸氨基酸)苯基氨基酸氨基酸(2)苯异硫氰酸酯(phenylisothiocyanate， PITC)在弱碱性条件下，与氨基酸反应在弱碱性条件下，生成苯乙内酰硫脲 PTH衍生物，(phenylthiohydantoin， PTH)衍生物，即PTH-氨基酸，此反应又称之Edman反应，该反应是蛋白质或多肽氨基酸序列测定常用的反应。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。