一种新型乳清蛋白肽的核磁共振研究
Research on a Novel Whey Peptide by Nuclear Magnetic Resonance (NMR) Spectroscopy

乳清蛋白经碱性蛋白酶酶解的产物,经超滤、凝胶过滤色谱以及反向高效液相色谱分离纯化得到一种纯度较高的多肽。多肽经液质分析,初步确定其氨基酸序列为Asp-Gln-Trp-Leu,为一种新的肽段。本文采用核磁共振波谱法[包括1H、13C、1H-1H COSY(1H-1H correlation spectroscopy),HMBC(heteronuclear multiple bond correlation),HMQC(heteronuclear multiple quantum coherence),TOCSY(total correlation spectroscopy),NOESY(nuclear overhauser effect spectroscopy)]对其结构进行了解析,并对核磁信号进行了归属。实验结果显示TOCSY、HMBC和NOESY技术在多肽核磁共振信号的归属中发挥着关键的作用。
A novel whey peptide was purified by ultrafiltration,Sephadex G-25 gel filtration chromatography and preparative HPLC from whey protein hydrolytes with alcalase.Its amino acid sequence was determined to be Asp-Gln-Trp-Leu by LC-MS,which is a novel peptide.This study focused on the structural elucidation of this peptide by NMR spectra(1H,13C,1H-1H COSY(1H-1H correlation Spectroscopy),HMBC(heteronuclear multiple bond correlation),HMQC(heteronuclear multiple quantum coherence),TOCSY(total correlation spectroscopy),NOESY(nuclear overhauser effect spectroscopy)).Our results showed that TOCSY,HMBC and NOESY play an important role in the assignment of NMR data for the structural elucidation of peptides.