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 - DFBPOPIO0128(Opioid peptide)

DFBP ID	DFBPOPIO0128
Peptide sequence	YPYY
Type	Native peptide
Peptide/Function name	Opioid peptide, Casoxin B

Function-activity relationship

Main bioactivity	Opioid activity
Otheir bioactivity	ACE-inhibitory activity ^[D1], Antihypertensive activity ^[D2], Antioxidative activity ^[D3], DPP IV-inhibitory activity ^[D4], Multifunctional activity ^[D5]

Calculated physicochemical properties

Three-letter amino acid

Tyr-Pro-Tyr-Tyr

Single-letter amino acid

YPYY

Peptide length

Peptide mass

Experimental mass	Theoretical mass
N.D	604.65 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

5.83 ^c

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

-1.3750^c

Hydrophilic residue ratio

25%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Human
Organism/Source	Human milk protein
Precursor protein	κ-Casein
Residue position	f(31-34)
Precursor protein(s) search	Source.1: DFBPPR1068 ---- Plant proteins ---- E3 ubiquitin-protein ligase DIS1 Source.2: DFBPPR2330 ---- Plant proteins ---- Probable staphylococcal-like nuclease CAN3 Source.3: DFBPPR2351 ---- Plant proteins ---- Dolichyl-diphosphooligosaccharide--protein glycosyltransferase 48 kDa subunit Source.4: DFBPPR2528 ---- Plant proteins ---- Probable staphylococcal-like nuclease CAN2 Source.5: DFBPPR7608 ---- Milk proteins ---- Kappa-casein Source.6: DFBPPR7686 ---- Milk proteins ---- Kappa-casein Source.7: DFBPPR7695 ---- Milk proteins ---- Kappa-casein Source.8: DFBPPR7715 ---- Milk proteins ---- Kappa-casein Source.9: DFBPPR8492 ---- Milk proteins ---- Kappa-casein Source.10: DFBPPR16086 ---- Animal proteins ---- Sodium/potassium-transporting ATPase subunit beta-1 Source.11: DFBPPR16300 ---- Animal proteins ---- Dolichyl-diphosphooligosaccharide--protein glycosyltransferase 48 kDa subunit Source.12: DFBPPR16581 ---- Animal proteins ---- NADH-ubiquinone oxidoreductase chain 5 Source.13: DFBPPR17095 ---- Animal proteins ---- Hyaluronidase-1 Source.14: DFBPPR18973 ---- Animal proteins ---- Transcriptional activator Myb Source.15: DFBPPR20798 ---- Animal proteins ---- Dolichyl-diphosphooligosaccharide--protein glycosyltransferase 48 kDa subunit Source.16: DFBPPR21306 ---- Animal proteins ---- Protein ATP1B4 Source.17: DFBPPR8538 ---- Animal proteins ---- Sodium/potassium-transporting ATPase subunit beta-1 Source.18: DFBPPR8745 ---- Animal proteins ---- Hyaluronidase-1 Source.19: DFBPPR9339 ---- Animal proteins ---- Dolichyl-diphosphooligosaccharide--protein glycosyltransferase 48 kDa subunit Source.20: DFBPPR9387 ---- Animal proteins ---- Protein ATP1B4 Source.21: DFBPPR10119 ---- Animal proteins ---- Down syndrome cell adhesion molecule homolog Source.22: DFBPPR10355 ---- Animal proteins ---- Down syndrome cell adhesion molecule-like protein 1 homolog Source.23: DFBPPR10358 ---- Animal proteins ---- Very-long-chain (3R)-3-hydroxyacyl-CoA dehydratase Source.24: DFBPPR10687 ---- Animal proteins ---- Transcriptional activator Myb Source.25: DFBPPR10752 ---- Animal proteins ---- Protein ATP1B4 Source.26: DFBPPR10897 ---- Animal proteins ---- Doublesex- and mab-3-related transcription factor 1 Source.27: DFBPPR11078 ---- Animal proteins ---- Sodium/potassium-transporting ATPase subunit beta-1 Source.28: DFBPPR11612 ---- Animal proteins ---- Dolichyl-diphosphooligosaccharide--protein glycosyltransferase 48 kDa subunit Source.29: DFBPPR12562 ---- Animal proteins ---- Sodium/potassium-transporting ATPase subunit beta-1 Source.30: DFBPPR13549 ---- Animal proteins ---- Sodium/potassium-transporting ATPase subunit beta-1 Source.31: DFBPPR14863 ---- Marine protein ---- Sodium/potassium-transporting ATPase subunit beta-233 Source.32: DFBPPR14868 ---- Marine protein ---- Sodium/potassium-transporting ATPase subunit beta-1
Link-research Inductive analysis	Link 1: DFBPOPIO0015----Bovine milk protien----κ-Casein

Biological/Functional activity & target protein

Opioid activity

Casoxin B showed weak opioid antagonist activity with a A₂ value of 200 μM. As shown in table 1.

Table 1 Opioid antagonist activities of peptide.
Peptide	Receptor assay ^a, IC₅₀, μM	GPI assay ^b, A₂, μM	References
Casoxin B	400	200	—
Casoxin B	Opioid antagonist, this peptide showed a relatively low opioid antagonistic activity in comparison to the esterified peptides (IC₅₀ data not shown) and has been characterized as μ-type ligands		[1]

^a Radioreceptor test performed in presence of 1 nM [³H]naloxone.
^b Concentration of opioid antagonist to make the IC₅₀ value of μ-receptor specific opioid agonist Tyr-D-Ala-Gly-MePhe-Glyol (DAGO) two-fold in the guinea pig ileum assay.

Specific target protein(s)

Specific Target Protein(s):
Mu-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)N1[C@@]([H])(CCC1)C(=O)N[C@@]([H])(Cc1ccc(O)cc1)C(=O)N[C@@]([H])(Cc1ccc(O)cc1)C(=O)O

Preparation method

Mode of preparation	Synthesis peptide
Enzyme(s)/starter culture	Peptide fragments of κ-casein were synthesized with a Sam 2 peptide synthesizer (Biosearch Inc.) by the t-Boc method.

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

Casoxin B also found in Bovine milk (κ-casein, 58-61, 61-64).

Database cross-references

DFBP

[D1]	DFBPACEI1213
[D2]	DFBPANHY0564
[D3]	DFBPANOX0680
[D4]	DFBPDPIV0040
[D5]	DFBPMUFU0253

[D6]

[D7]

[D8]

[D9]

Reference(s)

Primary literature	Chiba H, Tani F, Yoshikawa M. Opioid antagonist peptides derived from kappa-casein. J Dairy Res. 1989;56(3):363-6. PMID: 2760302 DOI: 10.1017/s0022029900028818
Other literature(s)	[1] Meisel H, Fitzgerald R J. Opioid peptides encrypted in intact milk protein sequences.[J]. British Journal of Nutrition, 2000, 84(S1):27-31.
PubDate	1989