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 - DFBPDPIV0107(DPP IV-inhibitory peptide)

DFBP ID	DFBPDPIV0107
Peptide sequence	LPQNIPPL
Type	Native peptide
Peptide/Function name	DPP-IV inhibitory peptide, Anti-diabetic peptide

Function-activity relationship

Main bioactivity	DPP-IV inhibitory activity
Otheir bioactivity	N.D

Calculated physicochemical properties

Three-letter amino acid

Leu-Pro-Gln-Asn-Ile-Pro-Pro-Leu

Single-letter amino acid

LPQNIPPL

Peptide length

Peptide mass

Experimental mass	Theoretical mass
N.D	891.06 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

5.97 ^c

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

0.0375^c

Hydrophilic residue ratio

75%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Animal
Organism/Source	Gouda-type cheese
Precursor protein	β-Casein
Residue position	f(70-77)
Precursor protein(s) search	Source.1: DFBPPR7718 ---- Milk proteins ---- Beta-casein Source.2: DFBPPR8489 ---- Milk proteins ---- Beta-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

DPP IV-inhibitory activity

(1) The peptide LPQNIPPL showed potent Dipeptidyl Peptidase IV (EC 3.4.14.5) inhibitory activity with the IC₅₀ value of 46 μM. However, the inhibitory activity of LPQNIPPL was approximately 10-fold lower than that of diprotin A (IPI), a well-known DPP-IV inhibitory peptide and approximately 100-fold lower than those of commercial drugs ^[1].
(2) Glucose tolerance tests were performed in rats orally administered synthesized LPQNIPPL (30 mg 100 g^-1 rat weight) with a cross-over experimental design. The post-prandial area under the blood glucose curve was significantly reduced (P < 0.02) in the LPQNIPPL-administered group compared with that in the placebo-treated group.

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

Preparation method

Mode of preparation	Extracting without enzyme
Enzyme(s)/starter culture	The water-soluble extracts of the gouda-type cheeses were prepared without enzyme.

Stability & Cytotoxicity

Peptide stability

Literature report:

Literature reported the gastrointestinal digestion of β-casein and showed that pepsin cleaved β-CN 70-71 and peptidases on Caco-2 cells cleaved β-CN 72-73^[2]. To compare the DPP-IV-inhibitory activity of LPQNIPPL and its derivatives, we synthesized PQNIPPL (β-CN f71-77) and LPQ (β-CN f70-72), cleaved peptides of LPQNIPPL, and evaluated their inhibitory activity. The IC₅₀ value of LPQ was sustained (82 μM), whereas that of PQNIPPL, which had lost the X-Pro structure at its N-terminus, was reduced to a considerable extent (1500 μM).

EHP-Tool:

Enzymatic Hydrolysis Prediction Tool (EHP-Tool)

Peptide cytotoxicity

Literature report:	N.D
Prediction:	ToxinPred

Additional information

This is the first report that has identified DPP-IV inhibitory casein-derived peptides from gouda-type cheese with an effect on plasma glucose in a rat model.

Database cross-references

[D1]

[D2]

[D3]

[D4]

Reference(s)

Primary literature	Uenishi, H., Kabuki, T., Seto, Y., Serizawa, A., Nakajima, H. Isolation and identification of casein-derived dipeptidyl-peptidase 4 (DPP-4)-inhibitory peptide LPQNIPPL from gouda-type cheese and its effect on plasma glucose in rats. International Dairy Journal. 2012, 22, 24-30. DOI: 10.1016/j.idairyj.2011.08.002
Other literature(s)	[1] Mcintosh C H, Demuth H U, Kim S J, et al. Applications of dipeptidyl peptidase IV inhibitors in diabetes mellitus[J]. International Journal of Biochemistry & Cell Biology, 2006, 38(5):860-872. [2] Ohsawa K, Satsu H, Ohki K, et al. Producibility and digestibility of antihypertensive beta-casein tripeptides, Val-Pro-Pro and Ile-Pro-Pro, in the gastrointestinal tract: analyses using an in vitro model of mammalian gastrointestinal digestion[J]. J Agric Food Chem, 2008, 56(3):854-858.
PubDate	2012