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 - DFBPAGPE0028(Alpha-gliadin peptide)

DFBP ID	DFBPAGPE0028
Peptide sequence	QEQVPLVQQQQF
Type	Native peptide
Peptide/Function name	α-Gliadin peptide A4

Function-activity relationship

Main bioactivity	Inhibitory activity of gliadin bonding with AGA
Otheir bioactivity	N.D

Calculated physicochemical properties

Three-letter amino acid

Gln-Glu-Gln-Val-Pro-Leu-Val-Gln-Gln-Gln-Gln-Phe

Single-letter amino acid

QEQVPLVQQQQF

Peptide length

Peptide mass

Experimental mass	Theoretical mass
1471.6220 Da	1471.65 Da ^c

Net charge

0.00 ^c

Isoelectric point (pI)

3.34 ^c

IC₅₀

N.D

pIC₅₀

N.D

GRAVY

-0.9250^c

Hydrophilic residue ratio

41.67%^c

Peptide calculator

Peptide source & Food-borne protein(s) search

Classification	Plant
Organism/Source	Wheat gluten
Precursor protein	α-Gliadin
Residue position	N.D
Precursor protein(s) search	Source.1: DFBPPR0379 ---- Plant protein ---- Alpha-gliadin Source.2: DFBPPR0380 ---- Plant protein ---- Alpha-gliadin Source.3: DFBPPR0381 ---- Plant protein ---- Alpha-gliadin Source.4: DFBPPR0384 ---- Plant protein ---- Alpha-gliadin Source.5: DFBPPR0389 ---- Plant protein ---- Alpha-gliadin Source.6: DFBPPR0390 ---- Plant protein ---- B3144=ALPHA-gliadin derived CELIAC active peptide Source.7: DFBPPR0391 ---- Plant protein ---- B3143=ALPHA-gliadin derived CELIAC active peptide Source.8: DFBPPR6853 ---- Plant proteins ---- Alpha/beta-gliadin MM1 Source.9: DFBPPR6930 ---- Plant proteins ---- Alpha/beta-gliadin Source.10: DFBPPR6938 ---- Plant proteins ---- Alpha/beta-gliadin clone PW8142 Source.11: DFBPPR6939 ---- Plant proteins ---- Alpha/beta-gliadin A-V Source.12: DFBPPR6941 ---- Plant proteins ---- Alpha/beta-gliadin A-I
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

Coeliac toxic activity

Sera of patients with coeliac disease, containing IgA and IgG antigliadin antibodies (AGA) and various IgA autoantibodies , react with isolated enterocytes. Reactivity of gliadin with all purified AGA tested was inhibited by peptide A4 (QEQVPLVQQQQF) at the N-terminal region of the gliadin molecule. AGA cross reactivity with enteroctyes and calreticulin was also inhibited by peptide A4. As dominant epitopes AGA of coeliac patients recognise similar structures corresponding to peptides A4 present on gliadin, enterocytes, and calreticulin. Substitution of glutamine in the A4 peptide by glutamic acid caused loss of inhibitory capacity. Shortening of peptide A4 on the N-terminal by three amino acids increased its inhibitory effect.

Specific target protein(s)

N.D

Taste properties & Structure

Bitterness

Literature report	N.D
Bitter prediction tools	Non-bitter taste ^prediction

SMILES

N[C@@]([H])(CCC(=O)N)C(=O)N[C@@]([H])(CCC(=O)O)C(=O)N[C@@]([H])(CCC(=O)N)C(=O)N[C@@]([H])(C(C)C)C(=O)N1[C@@]([H])(CCC1)C(=O)N[C@@]([H])(CC(C)C)C(=O)N[C@@]([H])(C(C)C)C(=O)N[C@@]([H])(CCC(=O)N)C(=O)N[C@@]([H])(CCC(=O)N)C(=O)N[C@@]([H])(CCC(=O)N)C(=O)N[C@@]([H])(CCC(=O)N)C(=O)N[C@@]([H])(Cc1ccccc1)C(=O)O

Preparation method

Mode of preparation	Synthesis peptide
Enzyme(s)/starter culture	The peptide was synthesised using the Fmoc/tBu protection strategy on aminomethyl copoly (styrene-1% divinylbenzene) resin with a Knorr linker.

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

(1) Coeliac disease is a permanent intolerance to the gluten or storage proteins found in some cereals. According to De Ritis and coworkers, small sequences of amino acids are common to the peptides linked with the toxicity. It has also been suggested that Tyr-containing motif is also associated with toxicity^[D1].
(2) Coeliac disease has many similarities with autoimmune system. Sera of patients with coeliac contain high concentration of antibodies to gliadin^[D1].
(3) AGA of patients with coeliac disease react with similar structures on gliadin and potential autoantigens on enterocytes^[0].

Database cross-references

[D1]

[D2]

[D3]

[D4]

Reference(s)

Primary literature	Krupicková S, Tucková L, Flegelová Z, Michalak M, Walters JR, Whelan A, Harries J, Vencovský J, Tlaskalová-Hogenová H. Identification of common epitopes on gliadin, enterocytes, and calreticulin recognised by antigliadin antibodies of patients with coeliac disease. Gut. 1999 Feb;44(2):168-73. PMID: 9895374 DOI: 10.1136/gut.44.2.168
Other literature(s)	[1] Karská K, Tucková L, Steiner L, et al. Calreticulin--the potential autoantigen in celiac disease.[J]. Biochemical & Biophysical Research Communications, 1995, 209(2):597.(AGPE0002)
PubDate	1999