Isolation, purification and characterisation of angiotensin I‐converting enzyme–inhibitory peptides derived from catfish (Clarias batrachus) muscle protein thermolysin hydrolysates

Abstract

Summary The angiotensin I‐converting enzyme (ACE)‐inhibitory activities of catfish (Clarias batrachus) muscle protein hydrolysates were investigated. Thermolytic digests of C. batrachus sarcoplasmic and myofibrillar proteins exhibited inhibitory activity towards ACE and were purified with the aim of ultrafiltration, gel filtration and reversed‐phase high‐performance liquid chromatography (RP‐HPLC). The amino acid sequences of hydrolysates with the highest ACE‐inhibitory activities were determined using electrospray quadrupole time‐of‐flight tandem mass spectrometry (ESI‐TOFQ MS/MS). The sequences of GPPP (IC50 = 0.86 μm) and IEKPP (IC50 = 1.2 μm) corresponding to the fragments 986–989 and 441–445 of myosin‐I heavy chain were identified for the sarcoplasmic and myofibrillar protein hydrolysates, respectively. Peptide GPPP exhibited a mixed‐type inhibition whereas peptide IEKPP could only bind to the active sites of ACE. The results demonstrate that hydrolysates of C. batrachus muscle proteins obtained by thermolysin may contain bioactive peptides.

Effect of Molecular Weight Reduction of Polypeptides on Angiotensin Converting Enzyme (ACE) Inhibitory Activity in Chicken Skin Hydrolysate (Collagen)

“…Sample with molecular weight of 3 -10kDa and sample with molecular weight 10 kDa does not have any significant difference (P 0.05) and this may indicate that peptides with larger molecular weight are present in the 3 -10 kDa sample fraction. Similar findings are reported by Ghassem et al [24] whereby sample with molecular weight less than 3 kDa has the highest ACE inhibitory activity and [27] where sample with molecular weight less than 1 kDa has the highest ACE inhibitory activity. Campos et al [27] reported that the ACE inhibitory activity is affected by the peptide chain containing less than 6 hydrophobic amino acids and this is supported by Zhang et al [17] that reported the ACE inhibitory activity is affected by the presence of hydrophobic amino asid at the C-terminal of a tripeptide.…”

“…These amino acids are able to convert the molybdate in folin-phenol reagent into the blue molybdium [21,22]. According to [23][24][25][26], ACE inhibitory activity is affected by the presence of the amino acid proline, phenylalanine or tyrosin at the terminal-C of peptide chain. Therefore the increase of the soluble protein content, may increase presence of these amino acids which can affect the ACE inhibitory activity.in the ultrafiltrated sample fraction hydrolysates.…”

Novel Peptide Sequences with ACE-Inhibitory and Antioxidant Activities Derived from the Heads and Bones of Hybrid Groupers (Epinephelus lanceolatus × Epinephelus fuscoguttatus)

“…The inhibitory kinetics of HB-IV and PeptACE on ACE were determined according to the method of Ghassem et al [ 39 ]. The ACE-inhibition were measured by varying the concentration of HHL (0.5, 1, 2, 4, and 6 mM) in the absence and presence of various concentrations of HB-IV and PeptACE.…”

Angiotensin I‐converting enzyme inhibitory activity of protein hydrolysates prepared from three freshwater carps (Catla catla, Labeo rohita and Cirrhinus mrigala) using Flavorzyme

“…The choice of enzyme for the preparation of protein hydrolysate will be critical as the properties of hydrolysates will depend on the nature of enzyme. Application of different proteolytic enzymes such as alcalase, neutrase, pepsin, papain, a-chymotrypsin, trypsin, protamex and thermolysin for the preparation of protein hydrolysate from tilapia protein, tuna frame protein, Acetes chinensis and cat fish muscle protein has been achieved (Cao et al, 2010;Lee et al, 2010;Ghassem et al, 2012;Charoenphun et al, 2013).…”