Department of Life Sciences and Food for Health Ireland (FHI), University of Limerick, Limerick, Ireland.
Peptides. 2013 Jan;39:157-63. doi: 10.1016/j.peptides.2012.11.016. Epub 2012 Dec 3.
Selected synthetic dipeptides and milk protein hydrolysates were evaluated for their dipeptidyl peptidase IV (DPP-IV) inhibitory properties, and their superoxide (SO) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities. DPP-IV inhibition was seen with eight out of the twelve dipeptides and 5 of the twelve hydrolysates studied. Trp-Val inhibited DPP-IV, however, inhibition was not observed with the reverse peptide Val-Trp. The most potent hydrolysate inhibitors were generated from casein (CasH2) and lactoferrin (LFH1). Two Trp containing dipeptides, Trp-Val and Val-Trp, and three lactoferrin hydrolysates scavenged DPPH. The dipeptides had higher SO EC(50) values compared to the milk protein hydrolysates (arising from three lactoferrin and one whey protein hydrolysates). Higher molecular mass fractions of the milk protein hydrolysates were associated with the SO scavenging activity. Trp-Val and one lactoferrin hydrolysate (LFH1) were multifunctional displaying both DPP-IV inhibitory and antioxidant (SO and DPPH scavenging) activities. These compounds may have potential as dietary ingredients in the management of type 2 diabetes by virtue of their ability to scavenge reactive oxygen species and to extend the half-life of incretin molecules.
选择合成二肽和乳蛋白水解物来评估它们对二肽基肽酶 IV（DPP-IV）的抑制特性，以及它们对超氧化物（SO）和 2,2-二苯基-1-苦基肼（DPPH）自由基的清除活性。在所研究的 12 个二肽和 5 个水解物中，有 8 个具有 DPP-IV 抑制作用。色氨酰缬氨酸抑制了 DPP-IV，但是没有观察到相反的肽缬氨酰-色氨酸。最有效的水解物抑制剂是由酪蛋白（CasH2）和乳铁蛋白（LFH1）生成的。两种含有色氨酸的二肽，色氨酰缬氨酸和缬氨酰-色氨酸，以及三种乳铁蛋白水解物可清除 DPPH。与乳蛋白水解物（来自三种乳铁蛋白和一种乳清蛋白水解物）相比，二肽的 SO EC（50）值更高。乳蛋白水解物的高分子质量分数与 SO 清除活性有关。色氨酰缬氨酸和一种乳铁蛋白水解物（LFH1）具有多功能性，同时具有 DPP-IV 抑制和抗氧化（SO 和 DPPH 清除）活性。这些化合物由于能够清除活性氧物种并延长肠促胰岛素分子的半衰期，因此可能具有作为 2 型糖尿病饮食成分的潜力。
