Spot

Mr (kDa)°

pI°

N-terminal sequence

Protein identification*

Accession no.*

A

33.74

4.63

RKEELNVSS

b-casein

P86273 (donkey)

B

33.54

4.72

RKEELNVSS

b-casein

P86273 (donkey)

C

33.10

4.82

RKEELNVSS

b-casein

P86273 (donkey)

D

33.54

4,92

RKEELNVSS

b-casein

P86273 (donkey)

E

31.66

4.68

RKEELNVSS

b-casein

P86273 (donkey)

F

31.48

4,80

RKEELNVSS

b-casein

P86273 (donkey)

G

32,15

4,88

RKEELNVSS

b-casein

P86273 (donkey)

H

31.15

4,95

RKEELNVSS

b-casein

P86273 (donkey)

I

31.20

5.15

RPKLPHRPE

αs1-casein

P86272(donkey)

J

31.14

5.23

RPKLPHRPE

αs1-casein

P86272(donkey)

L

31.14

5.36

RPKLPHRPE

αs1-casein

P86272 (donkey)

M

28.26

5.08

RPKLPHRPE

αs1-casein

P86272 (donkey)

N

27.24

4.92

RPKLPHRPE

αs1-casein

P86272 (donkey)

O

21.90

4.46

TNIPQTMQDLDLQEV

β-lactoglobulin 

P13613 (donkey)

P

20.0

4.40

TNIPQTMQDLDLQEV

β-lactoglobulin

P13613 (donkey)

Q

20.58

4.12

TNIPQTMQDLDLQEV

β-lactoglobulin

P13613 (donkey

R

13.04

4.76

KQFTKHELSQVLKSM

α-lactalbumin

P28546 (donkey)

S

12.98

5.26

KQFTKHELSQVLKSM

α-lactalbumin

P28546donkey)

T

14.5

9.40

KVFSKHELAHKL

lysozyme

P11375 (donkey)

U

66.3

6.62

DTHKSEIAHRFND

serum albumin

Q5XLE4 (donkey)

V

79.0

9.70

APRKSVRW

lactoferrin

O77811 (horse)

° The calculation of experimental pI and Mr was carried out using PDQuest software Version 7.1.1 (Bio-Rad Laboratories).
* NCBI BLAST database at http://blast.ncbi.nlm.nih.gov/
Table 2: Characterization of donkey’s milk protein fraction spots separated by 2-DE and subsequently stained or transferred on PVDF membranes for N-terminal analysis followed by search in NCBI database.