Hi WoA,
you may also try the ExprEssence plugin for Cytoscape, available at
http://sourceforge.net/projects/expressence/
published at
http://www.biomedcentral.com/1752-0509/4/164
ExprEssence can be used to identify protein interactions, whose
frequency increase or decrease from one to another experimental
condition. All you need to start is a protein interaction network and
proteome data sets for two conditions.
If any question arises, please feel free to contact me.
Best regards,
Gregor