Kornfelt T, Vinther A, Okafo G N, Camilleri P
Novo Nordisk A/S, Gentofte, Denmark.
J Chromatogr A. 1996 Mar 1;726(1-2):223-8. doi: 10.1016/0021-9673(95)01044-0.
By digestion of the highly basic polypeptide aprotinin or bovine pancreatic trypsin inhibitor (BPTI) with endoproteinase Lys-C after unfolding, reduction and pyridylethylation, five fragments are obtained. These fragments are separated by free solution capillary electrophoresis using a phosphate buffer at neutral pH. The effect of the ion-pairing buffer additive phytic acid on the separation was investigated. It is shown that phytic acid through ion-pair formation influences the mobility of only those peptide fragments having a net positive charge at the pH of the separation buffer. The affinity of phytic acid to the peptides correlates with their isoelectric point and the charge to mass ratios. Hence, by changing the concentration of phytic acid, it is possible to manipulate the migration order and the separation of the peptides.
在对高度碱性的多肽抑肽酶或牛胰蛋白酶抑制剂（BPTI）进行展开、还原和吡啶基乙基化处理后，用内肽酶Lys-C进行消化，可得到五个片段。使用中性pH的磷酸盐缓冲液，通过自由溶液毛细管电泳对这些片段进行分离。研究了离子对缓冲添加剂植酸对分离的影响。结果表明，植酸通过离子对的形成仅影响那些在分离缓冲液pH值下带净正电荷的肽片段的迁移率。植酸与肽的亲和力与它们的等电点和电荷质量比相关。因此，通过改变植酸的浓度，可以控制肽的迁移顺序和分离效果。
