Complex Networks

Protein Interaction Networks

 213

3−node graphlets

4−node graphlets

2 4

5

6

7

8

3

16

17

18 19

15

14

13121110

9

21

24 25

26

27

23

22 29

28

5−node graphlets

20

Figure 10.8: Graphlets of size 3, 4 and 5 (adapted from [30])

D(G

1

,G

2

) =

29

X

i=1

|F

i

(G

1

) −F

i

(G

2

)| (10.2)

where F

i

(G) = −logN

i

(G)/T(G). Testing the high confidence PPI networks using

this parameter, they concluded that the graphlet frequency distributions of these net-

works were close to the graphlet frequency distributions of geometric random net-

works. When noise in the PPI networks was considered, the graphlet distribution and

the global parameters of these networks were similar to those of scale-free networks.

Since ...