Effects of protein interaction data integration, representation and reliability on the use of network properties for drug target prediction

Table 10 Distribution of shortest path lengths from drug targets to the nearest disease protein

Distance	Description	Full PIN	BioGRID	Rual-Stelzl	Rual-only
0	Drug targets = DPs	436	319	71	25
1	Drug targets interact with DPs	619	246	47	10
2	Drug targets and DPs have a common interactor	154	163	77	25
3	3-step paths	12	16	20	11
4	4-step paths	1	1	1	2
5	5-step paths	-	1	-	-
Inf	Drug targets disconnected from DPs	5	5	5	1

The full PIN contains only 436 drug targets which, at the same time, are DPs. 619 different drug targets have a shortest path of “1” to the nearest DP (they interact), while 154 have a shortest path of “2” and 5 drug targets are disconnected from any disease target, probably due to missing interaction information. Smaller subsets show that, in general, drug targets do not get farther from disease proteins after data sub-setting, and, as a rule of thumb, there will always be a disease protein at least 4 steps away from any drug target. However, the proportion of drug targets in disconnected components is higher for subsets than it is for the full PIN.

ISSN: 1471-2105