Mech C, Jeschkeit H, Schellenberger A
Eur J Biochem. 1976 Jun 15;66(1):133-8. doi: 10.1111/j.1432-1033.1976.tb10433.x.
Two model peptides Ala-Ser-Asp-Tyr-Leu and Ala-Ser-Glu-Tyr-Leu have been synthesized and coupled with an without protecting groups to the amino groups of polystyrene resins. The yield in the binding operation was 93-97% by using water-soluble carbodiimides as condensing reagents. Edman degradation of the products and quantitative estimation of the amino acid phenylthio-hydantoins, as well as amino acid analysis of the partially and completely degraded resins, showed about 7-10% of the fixed peptides not to be involved in the degradation procedure. That part of the material which was not involved in the Edman degradation during the first step also remained inactive in the following degradation operations. The analytical data presented in the paper explain not only the course of the Edman degradation of peptides linked via the side-chain carboxylic groups to the resin, but they also describe the chemical reactivity of the various carboxylic groups in the binding operation. 22% of the peptides are bound to the resin by side-chain carboxylic groups in the case of the aspartate-containing peptide, 26-27% in the case of the glutamate-containing peptide. 75-77% and 72-75% respectively of the peptides are fixed to the resin via the C-terminal carboxylic group. No more than 3% of the fixed material may be bound bifunctionally to the support.
已合成了两种模型肽Ala-Ser-Asp-Tyr-Leu和Ala-Ser-Glu-Tyr-Leu，并在有或没有保护基团的情况下将它们与聚苯乙烯树脂的氨基偶联。通过使用水溶性碳二亚胺作为缩合试剂，结合操作的产率为93 - 97%。对产物进行埃德曼降解以及对氨基酸苯硫基乙内酰脲进行定量分析，同时对部分降解和完全降解的树脂进行氨基酸分析，结果表明约7 - 10%的固定肽未参与降解过程。在第一步中未参与埃德曼降解的那部分物质在后续的降解操作中也保持无活性。本文给出的分析数据不仅解释了通过侧链羧基与树脂相连的肽的埃德曼降解过程，还描述了结合操作中各种羧基的化学反应性。对于含天冬氨酸的肽，22%的肽通过侧链羧基与树脂结合；对于含谷氨酸的肽，这一比例为26 - 27%。分别有75 - 77%和72 - 75%的肽通过C端羧基固定在树脂上。固定物质中双功能结合到载体上的比例不超过3%。
