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 - DFBPDPIV0038(DPP IV-inhibitory peptide)

DFBP ID	DFBPDPIV0038
Peptide sequence	IPIQY
Type	Native peptide
Peptide/Function name	DPP-IV inhibitory peptide, Anti-diabetic peptide

Function-activity relationship

Main bioactivity	DPP-IV inhibitory activity
Otheir bioactivity	Antioxidative activity ^[D1], Multifunctional activity ^[D2]

Calculated physicochemical properties

Three-letter amino acid

Ile-Pro-Ile-Gln-Tyr

Single-letter amino acid

IPIQY

Peptide length

Peptide mass

Experimental mass	Theoretical mass
N.D	632.75 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

5.92 ^c

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

0.5200^c

Hydrophilic residue ratio

60%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Animal
Organism/Source	Bovine milk protein
Precursor protein	κ-Casein
Residue position	f(26-30)
Precursor protein(s) search	Source.1: DFBPPR7686 ---- Milk proteins ---- Kappa-casein Source.2: DFBPPR7695 ---- Milk proteins ---- Kappa-casein Source.3: DFBPPR7715 ---- Milk proteins ---- Kappa-casein Source.4: DFBPPR8492 ---- Milk proteins ---- Kappa-casein Source.5: DFBPPR10882 ---- Animal proteins ---- Noggin Source.6: DFBPPR15491 ---- Microorganism protein ---- Acyl-protein thioesterase 1
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

DPP IV-inhibitory activity	The peptide showed potent inhibitory activity for Dipeptidyl-peptidase IV (EC 3.4.14.5) with the IC₅₀ value of 35.2 ± 1.8 μM (p = 0.05). The peptide displayed a substrate-type of inhibition towards DPP-IV. Its DPP-IV inhibitory pattern was shown by Lineweaver–Burk plots to be a competitive inhibition pattern ^[2].
Specific target protein(s)	Specific Target Protein(s): Dipeptidyl peptidase 4

Taste properties & Structure

Bitterness

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

SMILES

N[C@@]([H])([C@]([H])(CC)C)C(=O)N1[C@@]([H])(CCC1)C(=O)N[C@@]([H])([C@]([H])(CC)C)C(=O)N[C@@]([H])(CCC(=O)N)C(=O)N[C@@]([H])(Cc1ccc(O)cc1)C(=O)O

Preparation method

Mode of preparation	Enzymatic hydrolysis
Enzyme(s)/starter culture	In silico digestion of individual milk proteins was carried out with the peptide cutter program (ExPASy, 2011) using gastrointestinal enzymes (pepsin, trypsin and chymotrypsin).

Stability & Cytotoxicity

Peptide stability

Literature report:

Table 1 Concentration of milk protein-derived peptides inducing 50% inhibition (IC₅₀) of dipeptidyl peptidase IV (DPP-IV) pre- (control) and post-hydrolysis of the milk protein-derived peptides with DPP-IV following incubation at 37 °C for 18 h at a low (1 U: 1 g peptide) and high (10 U: 1 g peptide) enzyme to substrate ratio (E:S).
Compound	DPP-IV IC₅₀^*
	Control	Low E:S	High E:S
IPIQY	26.7 ± 0.6 ^c	31.1 ± 0.3 ^c	40.4 ± 0.4 ^d
^* Values represent mean IC₅₀ values ± confidence interval (P = 0.05), n = 3. Values with different superscript letters are significantly different (P < 0.05).

EHP-Tool:

Enzymatic Hydrolysis Prediction Tool (EHP-Tool)

Peptide cytotoxicity

Literature report:	N.D
Prediction:	ToxinPred

Additional information

The results presented herein are relevant to the management of type 2 diabetes with functional foods involving multi-target sites for DPP-IV inhibition in humans.

Database cross-references

DFBP

[D1]	DFBPANOX0678
[D2]	DFBPMUFU0680

[D3]

[D4]

[D5]

[D6]

Reference(s)

Primary literature	Nongonierma AB, FitzGerald RJ. Susceptibility of milk protein-derived peptides to dipeptidyl peptidase IV (DPP-IV) hydrolysis. Food Chem. 2014 Feb 15;145:845-52. PMID: 24128555 DOI: 10.1016/j.foodchem.2013.08.097
Other literature(s)	[1] Nongonierma A B, Fitzgerald R J. An in silico model to predict the potential of dietary proteins as sources of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides[J]. Food Chemistry, 2014, 165(20):489-498. [2] Nongonierma A B, Fitzgerald R J. Structure activity relationship modelling of milk protein-derived peptides with dipeptidyl peptidase IV (DPP-IV) inhibitory activity[J]. Peptides, 2016, 79:1-7.
PubDate	2014