Potential Precursor of Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity and Structural Properties of Peptide from Peptic Hydrolysate of Cutlassfish Muscle

ABSTRACT

Peptic hydrolysates were prepared by digesting the cutlassfish muscle protein using pepsin for 1, 3, and 6 h, and their inhibitory activity against angiotensin-I converting enzyme (ACE) was studied. The ACE-inhibitory effect of the peptic hydrolysate of cutlassfish muscle generated at the 3 h time point exhibited the strongest activity. After identifying the optimal hydrolysate, the active peptide was isolated by ultrafiltration, gel permeation, and high performance liquid chromatography (HPLC). The resulting purified peptide was characterized using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/TOF MS/MS) and was identified to be a 496.44 Da pentapeptide (Phe-Ser-Gly-Gly-Glu). The ACE-inhibitory activity of the active peptide exhibited an IC₅₀ value of 0.033 ± 0.003 mg/ml. A molecular docking program was used to simulate the interaction between the peptide and ACE, which revealed that the inhibitory effect was mainly due to the hydrogen bonds between ACE and the peptide. Based on the ACE-inhibitory properties and the molecular docking study of the resulting active peptide, we demonstrated an increase in nitric oxide (NO) production in a dose-dependent manner. In conclusion, cutlassfish protein hydrolysate and the resulting active peptide could be used as active ingredients in functional food as anti-hypertensive agents.

KEYWORDS:

• Cutlassfish
• Angiotensin-I converting enzyme (ACE)
• inhibitory peptide
• peptic hydrolysate
• hypertension

Acknowledgments

This research was supported by the National Marine Biodiversity Institute of Korea Research Program 2020M00500. Further, the “Basic Science Research Program” extended its support via the National Research Foundation of Korea (NRF) which is sponsored through the Ministry of Education (NRF-2019R1C1C1009327).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Statement of informed consent, human/animal rights

No conflicts, informed consent, human or animal rights applicable.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10498850.2020.1773595

Additional information

Funding

This work was supported by the National Marine Biodiversity Institute of Korea [grant number 2020M00500]; National Research Foundation of Korea [grant number NRF-2019R1C1C1009327].