Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia.
Biopolymers. 2012;98(6):518-24. doi: 10.1002/bip.22121.
Cyclic disulfide-rich peptides ranging in size from ∼14 to 29 amino acids have been found in a wide variety of organisms and have exciting biological and medicinal applications due to their stability and structure. Many of these peptides can be chemically synthesized, but their small size and limited number of chromophore-containing amino acids make them difficult to quantify by methods routinely used for large proteins. A comparison of the precision and accuracy of gravimetric, UV- and NMR-based methods in current use for the quantification of small peptides is presented for a representative set of cyclic disulfide-rich peptides. The study shows that gravimetric and UV absorbance methods should be used with caution for small peptides and all methods should be carefully validated. For the routine quantification of small disulfide-rich peptides, we recommend comparison of the analytical reverse-phase high-performance liquid chromatography trace or UV absorbance at 214 nm with that of a standard peptide solution quantified by amino acid analysis. An accurate quantification method that is simple and cost effective will assist in comparison of inhibition and activity data between different laboratories and peptides and correct calculation of synthesis yields.
在广泛的生物体中发现了大小在 14 到 29 个氨基酸之间的环状二硫键丰富肽，由于其稳定性和结构，它们具有令人兴奋的生物学和医学应用。许多这些肽可以通过化学合成，但由于它们的小尺寸和有限数量的含生色团氨基酸，使得它们难以通过常规用于大蛋白质的方法进行定量。目前用于定量小肽的基于重量、UV 和 NMR 的方法的精度和准确性的比较，为一组代表性的环状二硫键丰富肽进行了介绍。该研究表明，对于小肽，应谨慎使用重量法和紫外吸收法，并且所有方法都应仔细验证。对于小的富含二硫键的肽的常规定量，我们建议将分析反相高效液相色谱图或在 214nm 处的紫外吸收与通过氨基酸分析定量的标准肽溶液的分析进行比较。简单且经济有效的准确定量方法将有助于比较不同实验室和肽之间的抑制和活性数据，并正确计算合成产率。
