Peptide properties

1Top 2Function-activity relationship 3Calculated physicochemical properties 4Peptide source & Food-borne protein(s) search 5Biological/Functional activity & target protein 6Taste properties & Structure 7Preparation method 8Stability & Cytotoxicity 9Additional information 10Database cross-references 11Reference(s)

List of peptide properties

DFBP ID - DFBPACEI1454(ACE-inhibitory peptide)

DFBP ID	DFBPACEI1454
Peptide sequence	HPFAQ
Type	Native peptide
Peptide/Function name	ACE-inhibitory peptide

Function-activity relationship

Main bioactivity	ACE-inhibitory activity
Otheir bioactivity	N.D

Calculated physicochemical properties

Three-letter amino acid

His-Pro-Phe-Ala-Gln

Single-letter amino acid

HPFAQ

Peptide length

Peptide mass

Experimental mass	Theoretical mass
598.3 Da	598.66 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

7.79 ^c

IC₅₀

465.0 ± 43.4 μM

pIC₅₀

-2.667

GRAVY

-0.7400^c

Hydrophilic residue ratio

60%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Animal
Organism/Source	Caprine milk protein, Caprine kefir
Precursor protein	β-Casein
Residue position	f(50-54)
Precursor protein(s) search	Source.1: DFBPPR5445 ---- Plant proteins ---- Bifunctional aspartokinase/homoserine dehydrogenase 2, chloroplastic Source.2: DFBPPR5447 ---- Plant proteins ---- Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic Source.3: DFBPPR7692 ---- Milk proteins ---- Beta-casein Source.4: DFBPPR7700 ---- Milk proteins ---- Beta-casein Source.5: DFBPPR7718 ---- Milk proteins ---- Beta-casein Source.6: DFBPPR8489 ---- Milk proteins ---- Beta-casein Source.7: DFBPPR19240 ---- Animal proteins ---- Isocitrate dehydrogenase [NAD] subunit beta, mitochondrial
Link-research Inductive analysis	There are no literature reports on the discovery of this sequence in other food-source proteins.

Biological/Functional activity & target protein

ACE-inhibitory activity	The peptide exhibited low Angiotensin-Converting Enzyme (ACE) (EC 3.4.15.1) inhibitory activity with an IC₅₀ value of 465.0 ± 43.4 μM.
Specific target protein(s)	Specific Target Protein(s): Angiotensin-converting enzyme

Taste properties & Structure

Bitterness

Literature report	N.D
Bitter prediction tools	Non-bitter taste ^prediction

SMILES

N[C@@]([H])(CC1=CN=C-N1)C(=O)N1[C@@]([H])(CCC1)C(=O)N[C@@]([H])(Cc1ccccc1)C(=O)N[C@@]([H])(C)C(=O)N[C@@]([H])(CCC(=O)N)C(=O)O

Preparation method

Mode of preparation	Fermentation
Enzyme(s)/starter culture	Kefir was prepared using pasteurized milk cultured with kefir grains that contained the lactic acid bacteria Lactococcus lactis, Lactococcus cremoris, Lactococcus biovar. diacetylactis, Leuconostoc mesenteroides ssp. cremoris, Lactobacillus plantarum, Lactobacillus casei, and the yeast Kluyveromyces marxianus var. fragilis (Torula kefir).

Stability & Cytotoxicity

Peptide stability

Literature report:

The peptide HPFAQ was not resistant to the incubation with pepsin followed by hydrolysis with Corolase PP.

Table 1. Behavior of angiotensin-converting enzyme (ACE)-inhibitory activity of peptides obtained from 3-kDa permeate of caprine kefir-water soluble extract under simulation of gastrointestinal digestion. Sequence and ACE-inhibitory activity of peptides released after digestion.
Sequence	IC₅₀, mg/mL ^a		Degree of hydrolysis	Fragments released after digestion
	Before digestion	After digestion
HPFAQ	0.278 ± 0.026	> 1	Hydrolyzed	HPFA; FAQ
^a Concentration of peptide needed to inhibit 50% the original ACE activity. Results are presented as the mean (n = 3) ± SD.

EHP-Tool:

Enzymatic Hydrolysis Prediction Tool (EHP-Tool)

Peptide cytotoxicity

Literature report:	No measured
Prediction:	ToxinPred

Additional information

N.D

Database cross-references

[D1]

[D2]

[D3]

[D4]

Reference(s)

Primary literature	Quirós, A., Hernández-Ledesma, B., Ramos, M., Amigo, L., Recio, I. Angiotensin-Converting Enzyme Inhibitory Activity of Peptides Derived from Caprine Kefir. Journal of Dairy Science. 2005, 88, 3480-7. DOI: 10.3168/jds.S0022-0302(05)73032-0
Other literature(s)	N.D
PubDate	2005