硅胶基质聚天冬氨酸固定相的合成及对多肽的分离

Preparation of a Silica-Based Stationary Phase with Polyaspartates and its Separation Behaviors for Peptides

分别将不同分子量的聚琥珀酰亚胺(PSI)化学键合到氨丙基硅胶表面得到4种键合聚天冬氨酸(YCSiP)的固定相材料(即YCSiP-Ⅰ、-Ⅱ、-Ⅲ和-Ⅳ),采用红外光谱、热重分析、扫描电镜和Zeta电位测定等方法进行表征,研究硅胶孔径、PSI的相对分子质量、流动相pH和离子强度等因素对分离多肽的影响.结果表明,在红外光谱中3 072、1 720和1 030 cm^(-1)等处吸收峰对应于v_(N—H)、v_(C=O)和v_(Si—O—Si)的伸缩振动峰,说明聚琥珀酰亚胺结合到硅胶上;YCSiP分离多肽主要受底物与固定相之间的静电作用影响;由小孔径的硅胶和低相对分子质量的聚琥珀酰亚胺制备得到的固定相YCSi P对多肽表现更好的分离性能;随着流动相的离子强度增大,多肽在固定相上的保留均显著减弱,在离子强度为50 mmol/L的流动相中,6种多肽在固定相上的分离效果最好.该研究丰富了硅胶基质聚天冬氨酸固定相材料在多肽分离中的应用.

Four silica-based packings bonded with polyaspartates（YCSiP-Ⅰ,-Ⅱ,-Ⅲ and-Ⅳ） were obtained through immobilization reaction between aminopropyl silica gel and polysuccinimides with different molecular weight,and characterized by FT-IR spectrum,thermal analysis,scanning electron microscope,and zeta potential measurement.Separation of six peptides on these stationary phases and the effects of pore size of silica,molecular weight of polysuccinimide,mobile phase pH and ionic strength on the separation were studied in detail.In the IR spectrum of YCSiP,the absorption bands at 3 072,1 720 and 1 030 cm-1 are attributed to the v（N—H）,v（C=O） and v（Si—O—Si） stretching vibrations,respectively,indicating that polysuccinimide was bound onto silica surface.Chromatographic results indicated that separation of peptides was mainly driven by different electrostatic attractions between peptide molecules and stationary phase materials.YCSiP-Ⅰmaterial derived from smaller-pore silica gel and lower-molecular-weight polysuccinimide showed better separation performance for these six peptides than the others.Moreover,retention of peptides turned weaker along with increasing ionic strength of the mobile phase from 25 to 100 mmol/L,and the best separation of these six peptides was achieved on the YCSiP-Ⅰcolumn in 50 mmol/L phosphate buffer solution.In brief,this study enriched potential applications of polyaspartate-bonded silica materials on peptide separation.