Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning 530008, China.
Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning 530008, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2020 Apr 15;1143:122042. doi: 10.1016/j.jchromb.2020.122042. Epub 2020 Feb 25.
Purification of small bioactive peptides from complex biological samples is a difficult task due to the interference of concentrated large biomolecules. In this study, a magnetic immobilized metal affinity chromatography matrix modified by poly (ethylene glycol) methyl ether (IMACM@mPEG) was prepared and applied for the rapid purification of angiotensin I-converting enzyme (ACE) inhibitory peptides from casein hydrolysate. The proposed IMACM@mPEG considerably reduced the non-specific adsorption of large proteins and exhibited improved purification efficiency towards ACE inhibitory peptides. A novel peptide with moderate ACE inhibitory activity (IC value of 274 ± 5 μM) was identified as LLYQEPVLGPVR. Lineweaver-Burk plot confirmed the non-competitive inhibition pattern of LLYQEPVLGPVR. The purified peptide was digested after simulated gastrointestinal digestion and produced shorter peptides which contributed to enhanced ACE inhibitory activity. These results indicated that the IMACM@mPEG is an effective method for the prepurification of ACE inhibitory peptide and the purified peptide LLYQEPVLGPVR may have potential as nutraceutical ingredient in functional foods for hypertension treatments.
从复杂的生物样品中纯化小生物活性肽是一项艰巨的任务，因为浓缩的大分子生物会产生干扰。在本研究中，制备了一种通过聚乙二醇甲醚（mPEG）修饰的磁性固定化金属亲和层析基质（IMACM@mPEG），并将其用于从酪蛋白水解物中快速纯化血管紧张素转化酶（ACE）抑制肽。所提出的 IMACM@mPEG 大大减少了大蛋白的非特异性吸附，并表现出对 ACE 抑制肽更高的纯化效率。鉴定出一种具有中等 ACE 抑制活性（IC 值为 274±5 μM）的新型肽，其序列为 LLYQEPVLGPVR。Lineweaver-Burk 图证实了LLYQEPVLGPVR 的非竞争性抑制模式。在模拟胃肠道消化后对纯化肽进行消化，产生了具有增强 ACE 抑制活性的较短肽。这些结果表明，IMACM@mPEG 是一种有效的 ACE 抑制肽预纯化方法，纯化的 LLYQEPVLGPVR 肽可能具有作为高血压治疗功能性食品的营养成分的潜力。
