Novel angiotensin I-converting enzyme inhibitory peptides derived from an edible mushroom, Pleurotus cystidiosus O.K. Miller identified by LC-MS/MS

Abstract

BackgroundAngiotensin I-converting enzyme (ACE) inhibitors have been reported to reduce mortality in patients with hypertension. Compared to chemosynthetic drugs, ACE inhibitors derived from natural sources such as food proteins are believed to be safer for consumption and to have fewer adverse effects. Some edible mushrooms have been reported to significantly reduce blood pressure after oral administration. In addition, mushrooms are known to be rich in protein content. This makes them a potential source of ACE inhibitory peptides. Hence, the objective of the current study was to isolate and characterise ACE inhibitory peptides from an edible mushroom, Pleurotus cystidiosus.MethodsACE inhibitory proteins were isolated from P. cystidiosus based on the bioassay guided purification steps, i.e. ammonium sulphate precipitation, reverse phase high performance liquid chromatography and size exclusion chromatography. Active fraction was then analysed by LC-MS/MS and potential ACE inhibitory peptides identified were chemically synthesized. Effect of in vitro gastrointestinal digestions on the ACE inhibitory activity of the peptides and their inhibition patterns were evaluated.ResultsTwo potential ACE inhibitory peptides, AHEPVK and GPSMR were identified from P. cystidiosus with molecular masses of 679.53 and 546.36 Da, respectively. Both peptides exhibited potentially high ACE inhibitory activity with IC50 values of 62.8 and 277.5 μM, respectively. SEC chromatograms and BIOPEP analysis of these peptides revealed that the peptide sequence of the hexapeptide, AHEPVK, was stable throughout gastrointestinal digestion. The pentapeptide, GPSMR, was hydrolysed after digestion and it was predicted to release a dipeptide ACE inhibitor, GP, from its precursor. The Lineweaver-Burk plot of AHEPVK showed that this potent and stable ACE inhibitor has a competitive inhibitory effect against ACE.ConclusionThe present study indicated that the peptides from P. cystidiosus could be potential ACE inhibitors. Although these peptides had lower ACE inhibitory activity compared to commercial antihypertensive drugs, they are derived from mushroom which could be easily obtained and should have no side effects. Further in vivo studies can be carried out to reveal the clear mechanism of ACE inhibition by these peptides.

Antioxidant activity, anti-proliferative activity, and amino acid profiles of ethanolic extracts of edible mushrooms

“…Although qualitative screening of chemical compounds found in mushrooms have been conducted using different analytical techniques (Petrova et al, 2007;Kanagasabapathy et al, 2011;Lau et al, 2013;Mohd Jamil et al, 2013), our metabolite profile study of these three edible mushrooms was performed for the first time via UPLC-HRMS. Chromatograms for the positive modes of all mushroom extracts studied are compared in Figure 5.…”

Discovery of Anti-Hypertensive Oligopeptides from Adlay Based on In Silico Proteolysis and Virtual Screening

“…Meanwhile, various methods were also developed for in silico proteolysis to analyze the potential cleavage sites of protein sequences, such as BIOPEP [10] and PeptideCutter [11], which can be utilized to in silico hydrolyze known protein sequences, discover novel oligopeptides, and illuminate the action mechanism of natural proteins. Compared to in vivo proteolysis, the accuracy of in silico proteolysis has been validated by multiple approaches, including liquid chromatograph-mass spectrometer (LC-MS) [10,12,13,14]. In silico proteolysis is widely used to analyze natural proteins and generate bioactive peptides from food and halobios, such as milk, meat, tilapia, sea cucumber and so on [15,16,17,18].…”

The Effect of Selected Cultivation Factors on the Growth of Mycelium of Pleurotus cystidiosus Miller

“…In addition to the culinary qualities of fruiting bodies, P. cystidiosus has a high nutritional value (proteins, fibre, minerals and vitamins) and the content of biologically active substances with proven health-promoting properties. The biological activity of these mushrooms has been confirmed in several laboratory tests and clinical trials, which showed, among others, their antitumor, anti-inflammatory, antiallergic, antiatherosclerotic, antibacterial, antiviral, antifungal, immunomodulatory and hepatoprotective properties as well as lowering blood sugar levels and the effect of blood cholesterol This mushroom is low in calories due to the limited content of lipids (Manzi and Pizzoferrato, 2000;Wasser, 2002;Croan, 2004;Thekkuttuparambil and Kainoor, 2007;Karaman et al, 2010;Abdullah et al, 2012;Patel et al, 2012;Lau et al, 2013;Siwulski et al, 2014;Usami et al, 2014).…”

“…Earlier documentation states that oyster mushrooms can be grown on a variety of waste materials, such as: various types of straw and sawdust, cotton waste, chopped and corn stover, waste from the production of palm oil, tea leaves, chopped cocoa pods (Vilgalys et al, 1996;Croan, 2004;Lau et al, 2013;Usami et al, 2014). During the last few years, there has been a very dynamic development in the production of edible and medicinal mushrooms.…”

“…Wheat agar medium was used in the experiment in Petri dishes 90 mm: wheat -extract from 200 g of wheat grains, horticultural, forestry and textile industry waste (Cohen et al, 2002;Croan, 2004;Lau et al, 2013;Usami et al, 2014). It is cultivated mainly in Asia, particularly in China, Thailand and Taiwan (Hanelt, 2001;Stamets, 2011;Usami et al, 2014).…”