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 - DFBPOPIO0006(Opioid peptide)

DFBP ID	DFBPOPIO0006
Peptide sequence	YLGSGY
Type	Native peptide
Peptide/Function name	Opioid peptide, Lactoferroxin A

Function-activity relationship

Main bioactivity	Opioid activity
Otheir bioactivity	N.D

Calculated physicochemical properties

Three-letter amino acid

Tyr-Leu-Gly-Ser-Gly-Tyr

Single-letter amino acid

YLGSGY

Peptide length

Peptide mass

Experimental mass	Theoretical mass
N.D	658.70 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

5.87 ^c

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

-0.0667^c

Hydrophilic residue ratio

50%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Human
Organism/Source	Human whey protein
Precursor protein	Lactoferrin
Residue position	f(318-323)
Precursor protein(s) search	Source.1: DFBPPR7596 ---- Milk proteins ---- Lactotransferrin
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

Lactoferroxin A have opioid activity as an antagonist peptide and showed preference for μ-receptors. As shown in table 1.

Tabel 1 The opioid activity of peptide and their analogues
Peptides	IC₅₀ (uM)^a	pA₂^b	Receptor affinity (IC₅₀, uM)			Antagonism (pA₂)
			μ	δ	κ	μ, GPI ^c	δ, MVD ^d	κ, RVD ^e
			[³H]DAGO	[³H]DADLE	[³H]EKC	DAGO	DADLE	Dyn. A[1-13]
YLGSGY	15.0	5.66	－	－	－	－	－	－
YLGSGY-OCH₃	15.3	5.62	19.3	45.0	> 500	5.68	4.38	4.92

^a Molar concentration that inhibits the binding of [³H]naloxone to opioid receptors of the rat brain membrane preparation by 50%.
^b Negative logarithm of the molar concentration that reduces the activity of morphiceptin in the guinea pig ileum assay by 50%.
^c Guinea pig ileum.^d Mouse vas deferens.^e Rabbit vas deferens.

Specific target protein(s)

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

Taste properties & Structure

Bitterness

Literature report	N.D
Bitter prediction tools	No prediction can be made about the peptide bitterness. ^prediction

SMILES

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

Preparation method

Mode of preparation	Enzymatic hydrolysis
Enzyme(s)/starter culture	Hydrolysis with an artificially methyl-esterified pepsin.

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

[D1]

[D2]

[D3]

[D4]

Reference(s)

Primary literature	Tani F, Iio K, Chiba H, Yoshikawa M. Isolation and characterization of opioid antagonist peptides derived from human lactoferrin. Agric Biol Chem. 1990 Jul;54(7):1803-10. PMID: 1369293
Other literature(s)	[1] Park Y W. Bioactive Components in Milk and Dairy Products[M]. 2009. [2] Kostyra E, Sienkiewiczsz┅apka E, Jarmo┅owska B, et al. Opioid peptides derived from milk proteins.[J]. Polish Journal of Food & Nutrition Sciences, 2004.
PubDate	1990