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 - DFBPDPIV0011(DPP IV-inhibitory peptide)

DFBP ID	DFBPDPIV0011
Peptide sequence	LKPTPEGDL
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-Lys-Pro-Thr-Pro-Glu-Gly-Asp-Leu

Single-letter amino acid

LKPTPEGDL

Peptide length

Peptide mass

Experimental mass	Theoretical mass
969.10 Da	969.09 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

4.37

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

-0.8444^c

Hydrophilic residue ratio

55.56%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Animal
Organism/Source	Bovine whey protein
Precursor protein	β-Lactoglobulin
Residue position	f(46-54)
Precursor protein(s) search	Source.1: DFBPPR7714 ---- Milk proteins ---- Beta-lactoglobulin Source.2: DFBPPR8499 ---- Milk proteins ---- Beta-lactoglobulin
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

Inhibitor of Dipeptidyl Peptidase IV (EC 3.4.14.5). The peptide showed potent DPP-IV inhibitory activity with IC₅₀ value of 45 μM, however, it was about 10 times less potent than the reference inhibitor diprotin A (4.7 μM). As shown in table 1.

Table 1 Dipeptidyl peptidase-IV inhibitory activity and mode of inhibition of synthesized peptides
Protein of origin	Peptide sequence	% DPP-IV inhibition ^a	IC₅₀ (μM) ^b	Mode of inhibition
α-Lactalbumin	WLAHKAL	33	286	Non-competitive
	WLAHKALCSEKLDQ	44	141	Un-competitive
	LAHKALCSEKL	41	165	Competitive
	LCSEKLDQ	46	186	Non-competitive
	TKCEVFRE	23	166	Un-competitive
	IVQNNDSTEYGLF	41	337	Non-competitive
	ILDKVGINY	34	263	Competitive
β-Lactoglobulin	LKPTPEGDL	73	45	Un-competitive
	LKPTPEGDLEIL	67	57	Un-competitive
	IPAVFKIDA	38	191	Competitive
Diprotin A^c	IPI	Not applicable	4.7	Competitive

^a The percent DPP-IV inhibition values are reported as the mean from triplicate determinations and measured using 125 μM of peptides (final assay concentration). Percent inhibition values not sharing any common lower case letters are significantly different (P < 0.05).
^b IC₅₀ values are reported as the mean from triplicate determinations and expressed as final assay concentration. Values not sharing any common lower case letters are significantly different (P < 0.05).
^c The inhibitory activity and mode of inhibition of diprotin A were included as references^[1].

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

Preparation method

Mode of preparation	Enzymatic hydrolysis
Enzyme(s)/starter culture	Whey protein isolate hydrolysates were prepared by digestion with pepsin using a 4% (w/w) enzyme/substrate ratio and incubating at pH 2.0 and 37 ℃ for 60 min.

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	Lacroix IM, Li-Chan EC. Isolation and characterization of peptides with dipeptidyl peptidase-IV inhibitory activity from pepsin-treated bovine whey proteins. Peptides. 2014 Apr;54:39-48. PMID: 24440459 DOI: 10.1016/j.peptides.2014.01.002
Other literature(s)	[1] Umezawa H, Aoyagi T, Ogawa K, et al. Diprotins A and B, inhibitors of dipeptidyl aminopeptidase IV, produced by bacteria[J]. Journal of Antibiotics, 1984, 37(4):422.
PubDate	2014