1. Characterization of ACE-inhibitory peptide associated with antioxidant and anticoagulation properties
Zhipeng Yu, Yongguang Yin, Wenzhu Zhao, Fei Wang, Yiding Yu, Boqun Liu, Jingbo Liu, Feng Chen J Food Sci. 2011 Oct;76(8):C1149-55. doi: 10.1111/j.1750-3841.2011.02367.x.
A bioactive peptide Arg-Val-Pro-Ser-Leu (RVPSL) obtained from egg white protein was characterized by LC-MS and further chemically synthesized by the Fmoc solid phase method and investigated in terms of its angiotensin converting enzyme (ACE)-inhibitory activity, antioxidant property, and anticoagulation activity, as well as its stability in a simulated gastrointestinal digestion. The peptide exhibited an ACE-inhibitory activity with an IC(50) value of 20 μM. Also, the peptide could efficiently quench the (1,1)-diphenyl-2-picrylhydrazyl free radicals and exhibit high anticoagulation activity with a complete inhibition at 100 mM. Moreover, the peptide has a good stability against protease digestion. These results suggest that the peptide RVPSL may have potential to be used in nutraceuticals and functional food. Practical Application: The present research revealed a novel multifunctional peptide hydrolyzed from egg white protein. The peptide RVPSL was not only able to block the amplification of the coagulation cascade, but also able to inhibit ACE activity.
2. Angiotensin I converting enzyme inhibitory peptides from simulated in vitro gastrointestinal digestion of cooked eggs
Kaustav Majumder, Jianping Wu J Agric Food Chem. 2009 Jan 28;57(2):471-7. doi: 10.1021/jf8028557.
Egg proteins are an excellent source of bioactive peptides. The purpose of this work was to study the effect of cooking methods on the production of angiotensin converting enzyme (ACE) inhibitory peptides. Boiled or fried eggs (in the forms of whites, yolks, and whole eggs) were digested by gastrointestinal tract proteases at simulated gut conditions. Fried egg digests showed more potent activity than those of boiled egg digests; the fried whole egg digest had an IC(50) value of 0.009 mg protein/mL. This hydrolysate was further purified by cation exchange chromatography and gel filtration chromatography. Seven peptides, Val-Asp-Phe (IC(50): 6.59 microM), Leu-Pro-Phe (10.59 microM), Met-Pro-Phe (17.98 microM), Tyr-Thr-Ala-Gly-Val (23.38 microM), Glu-Arg-Tyr-Pro-Ile (8.76 microM), Ile-Pro-Phe (8.78 microM), and Thr-Thr-Ile (24.94 microM), were identified by liquid chromatography-mass spectrometry (LC-MS/MS), and their IC(50) values were predicted by using our previously reported structure and activity models. The presence of several tripeptides from in vitro simulated gastrointestinal egg digest indicates that these peptides may be absorbed into the body and exert an in vivo antihypertensive activity, although in vivo study is needed to confirm this assumption. Our results showed that in vitro digestion of cooked eggs could generate a number of potent ACE inhibitory peptides which may have implications for cardiovascular disease prevention, including hypertension.
3. Angiotensin I-converting enzyme inhibitory peptide derived from glycinin, the 11S globulin of soybean (Glycine max)
K G Mallikarjun Gouda, Lalitha R Gowda, A G Appu Rao, V Prakash J Agric Food Chem. 2006 Jun 28;54(13):4568-73. doi: 10.1021/jf060264q.
Angiotensin I-converting enzyme (ACE), a dipeptidyl carboxypeptidase, catalyzes the conversion of Angiotensin I to the potent vasoconstrictor Angiotensin II and plays an important physiological role in regulating blood pressure. Inhibitors of angiotensin 1-converting enzyme derived from food proteins are utilized for pharmaceuticals and physiologically functional foods. ACE inhibitory properties of different enzymatic hydrolysates of glycinin, the major storage protein of soybean, have been demonstrated. The IC50 value for the different enzyme digests ranges from 4.5 to 35 microg of N2. The Protease P hydrolysate contained the most potent suite of ACE inhibitory peptides. The ACE inhibitory activity of the Protease P hydrolysate after fractionation by RP-HPLC and ion-pair chromatography was ascribed to a single peptide. The peptide was homogeneous as evidenced by MALDI-TOF and identified to be a pentapeptide. The sequence was Val-Leu-Ile-Val-Pro. This peptide was synthesized using solid-phase FMOC chemistry. The IC50 for ACE inhibition was 1.69 +/- 0.17 microM. The synthetic peptide was a potent competitive inhibitor of ACE with a Ki of 4.5 +/- 0.25 x 10(-6) M. This peptide was resistant to digestion by proteases of the gastrointestinal tract. The antihypertensive property of this peptide derived from glycinin might find importance in the development of therapeutic functional foods.
