An astonishing diversity of biological concepts and processes can be
represented by the relatively simple formalism of networks, which
consist of nodes connected by edges. Examples range from neuron
communication to metabolism and protein-protein interactions. The
development of a unified framework for the analysis and integration of
these data has appeared as a central challenge in bioinformatics research.
This presentation focuses on two applications for the manipulation and
investigation of biological networks. The Cytoscape plugin named
NetworkAnalyzer facilitates topological analysis of large networks
through computation and visualization of a variety of network
parameters. The stand-alone tool NetworkLoader compiles interaction
networks from different molecular interaction datasets, providing
flexible criteria for data filtering and integration of identifiers.
In addition, the talk presents an adaptable approach for quantifying the
topological role of a subset of nodes in a network. The approach
consists of estimating p-values for a collection of topological
properties. Its application to groups of polyanion-binding proteins
within protein-protein interaction networks in yeast and human revealed
intriguing topological features of some of the analyzed groups.