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 - DFBPOPIO0009(Opioid peptide)

DFBP ID	DFBPOPIO0009
Peptide sequence	YLGYLE
Type	Native peptide
Peptide/Function name	Opioid peptide, α_s1-Casein exorphin (2-7)^[3]

Function-activity relationship

Main bioactivity	Opioid activity
Otheir bioactivity	N.D

Calculated physicochemical properties

Three-letter amino acid

Tyr-Leu-Gly-Tyr-Leu-Glu

Single-letter amino acid

YLGYLE

Peptide length

Peptide mass

Experimental mass	Theoretical mass
N.D	756.84 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

3.34 ^c

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

0.1833^c

Hydrophilic residue ratio

50%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Animal
Organism/Source	Bovine milk protien
Precursor protein	α_s1-Casein
Residue position	f(91-96)
Precursor protein(s) search	Source.1: DFBPPR7688 ---- Milk proteins ---- Alpha-S1-casein Source.2: DFBPPR7694 ---- Milk proteins ---- Alpha-S1-casein Source.3: DFBPPR7717 ---- Milk proteins ---- Alpha-S1-casein Source.4: DFBPPR8488 ---- Milk proteins ---- Alpha-S1-casein
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

The peptide YLGYLE was specific ligands for the u- and δ-receptor. It showed opioid activity as measured by several standard assay procedures. As shown in table 1.

Table 1 Opioid activity of peptide
Peptide	Opiate assay (IC₅₀, uM)/Activity
Peptide	Displacement of [³H]DALAMID from rat brain membranes	Displacement of [³H]DHM from rat brain membranes	Inhibition of adenylate cyclase in homogenates of NG108-15 cells	Inhibition of electrically stimulated mouse vas deferens
Isolated α-casein exorphin ^a	－	3.8	0.3	11.0
YLGYLE	5.2	45.0	4.0	> 100.0
YLGYLE	Opioid agonist, (μ/δ)-receptor ^[3]

^a Opioid peptides from pepsin hydrolysates of α-casein.

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

Preparation method

Mode of preparation	Enzymatic hydrolysis
Enzyme(s)/starter culture	Hydrolysis with Pepsin.

Stability & Cytotoxicity

Peptide stability

Literature report:	The peptide was resistant to hydrolysis by trypsin and homogenates of rat brain membranes, but was partially inactivated by chymotrypsin and subtilisin.
EHP-Tool:	Enzymatic Hydrolysis Prediction Tool (EHP-Tool)

Peptide cytotoxicity

Literature report:	N.D
Prediction:	ToxinPred

Additional information

N.D

Database cross-references

[D1]

[D2]

[D3]

[D4]

Reference(s)

Primary literature	Loukas S, Varoucha D, Zioudrou C, Streaty RA, Klee WA. Opioid activities and structures of alpha-casein-derived exorphins. Biochemistry. 1983 Sep 13;22(19):4567-73. PMID: 6313043 DOI: 10.1021/bi00288a034
Other literature(s)	[1] Park Y W. Bioactive Components in Milk and Dairy Products[M]. 2009. [2] Meisel H. Overview on Milk Protein-derived Peptides[J]. International Dairy Journal, 1998, 8(5–6):363-373. [3] Teschemacher H. Opioid receptor ligands derived from food proteins.[J]. Current Pharmaceutical Design, 2003, 9(16):-.
PubDate	1983