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 - DFBPOPIO0052(Opioid peptide)

DFBP ID	DFBPOPIO0052
Peptide sequence	YGGFL
Type	Native peptide
Peptide/Function name	Opioid peptide, Leucine-enkephalin

Function-activity relationship

Main bioactivity	Opioid activity
Otheir bioactivity	Antioxidative activity ^[D1], Multifunctional activity ^[D2]

Calculated physicochemical properties

Three-letter amino acid

Tyr-Gly-Gly-Phe-Leu

Single-letter amino acid

YGGFL

Peptide length

Peptide mass

Experimental mass	Theoretical mass
N.D	555.63 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

5.92 ^c

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

0.9000^c

Hydrophilic residue ratio

80%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Animal
Organism/Source	Pig brain
Precursor protein	Pituitary gland
Residue position	N.D
Precursor protein(s) search	Source.1: DFBPPR2682 ---- Plant proteins ---- Beta-glucosidase 30 Source.2: DFBPPR3043 ---- Plant proteins ---- Beta-glucosidase 24 Source.3: DFBPPR3109 ---- Plant proteins ---- Beta-glucosidase 28 Source.4: DFBPPR3173 ---- Plant proteins ---- Beta-glucosidase 29 Source.5: DFBPPR5377 ---- Plant proteins ---- 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1, chloroplastic Source.6: DFBPPR5456 ---- Plant proteins ---- 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 2, chloroplastic Source.7: DFBPPR6628 ---- Plant proteins ---- 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1a, chloroplastic Source.8: DFBPPR6629 ---- Plant proteins ---- 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1d, chloroplastic Source.9: DFBPPR6630 ---- Plant proteins ---- 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1b, chloroplastic Source.10: DFBPPR6631 ---- Plant proteins ---- 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1c, chloroplastic Source.11: DFBPPR8451 ---- Plant proteins ---- 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase, chloroplastic Source.12: DFBPPR16933 ---- Animal proteins ---- Proenkephalin-A Source.13: DFBPPR18352 ---- Animal proteins ---- Proenkephalin-B Source.14: DFBPPR18741 ---- Animal proteins ---- Coatomer subunit beta' Source.15: DFBPPR21616 ---- Animal proteins ---- Olfactomedin-like protein 3 Source.16: DFBPPR8967 ---- Animal proteins ---- Proenkephalin-B
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

Opioid activity

Leucine-enkephalins has potent agonist activity at opiate receptor sites in that they produce a dose-related inhibition of electrically evoked contractions of the mouse vas deferens (MVD, δ-opiate receptor) and the guinea pig ileum (GPI, μ-opiate receptor). Leucine-enkephalin has half the potency of that of methionine-enkephalin in the vas deferens but in the guinea pig ileum only one-fifth of that of methionine-enkephalin. As shown in Table 1^[1].

Table 1 Opioid activities and receptor affinities and yields of opioid peptides in the pepsin-pancreatic elastase and the pepsin-thermolysin digests
Peptides	Receptor affinities (IC₅₀)		μ/δ	Opioid activities (IC₅₀)		μ/δ
	[³H]DAGO	[³H]DADLE		GPI	MVD
	μ (μM)	δ (μM)		μ (μM)	δ (μM)
GYYPTS	1000	5.0	202	> 1000	72	－
GYYPT	700	1.5	467	1000	60	16.7
GYYP	> 1000	3.8	－	> 1000	70	－
RYYP	(a)	(a)	－	> 1000	190	－
SYYP	> 1000	5.6	－	> 1000	200	－
WYYP	700	100	7	(a)	(b)	－
YYPT	(a)	(a)	－	(a)	800	－
YYP	> 1000	100	－	> 1000	1000	－
GYY	> 1000	500	－	> 1000	1000	－
YGGWL	0.045	0.005	9	0.05	0.017	2.9
YGGW	0.17	0.18	0.94	1.5	3.4	0.44
YGGFL	0.037	0.003	12.3	0.04	0.004	10

(a), not determined; (b), this peptide displayed opioid antagonist activity on the MVD assay. (pA₂ value = 3.3)

Specific target protein(s)

Specific Target Protein(s):
Mu-type opioid receptor
Delta-type opioid receptor

Taste properties & Structure

Bitterness

Literature report	N.D
Bitter prediction tools	Bitter taste ^prediction

SMILES

N[C@@]([H])(Cc1ccc(O)cc1)C(=O)NCC(=O)NCC(=O)N[C@@]([H])(Cc1ccccc1)C(=O)N[C@@]([H])(CC(C)C)C(=O)O

Preparation method

Mode of preparation	Hydrolysis without enzyme
Enzyme(s)/starter culture	The pig brains were hydrolyzed with 5.5 N HCl at 110 ℃ for 20 h.

Stability & Cytotoxicity

Peptide stability

Literature report:	N.D
EHP-Tool:	Enzymatic Hydrolysis Prediction Tool (EHP-Tool)

Peptide cytotoxicity

Literature report:	N.D
Prediction:	ToxinPred

Additional information

N.D

Database cross-references

DFBP

[D1]	DFBPANOX0588
[D2]	DFBPMUFU0667

BIOPEP-UWM

[D3]

2879, 8122, 9521

APD

[D4]

BioPepDB

[D5]

MBPDB

[D6]

Reference(s)

Primary literature	Hughes J, Smith TW, Kosterlitz HW, Fothergill LA, Morgan BA, Morris HR. Identification of two related pentapeptides from the brain with potent opiate agonist activity. Nature. 1975 Dec 18;258(5536):577-80. PMID: 1207728 DOI: 10.1038/258577a0
Other literature(s)	[1] Fukudome S I, Yoshikawa M. Opioid peptides derived from wheat gluten: Their isolation and characterization[J]. Febs Letters, 1992, 296(1):107-111.
PubDate	1975