Symmetry Of Network And Its Application In The Protein-Protein Interaction Network

In post-genomic era, the gene order has been decoded, but the biological functionis still shrouded in mystery. Accompanied by the rapid development of bioticexperiment, a large protein-protein interaction network database, which containsimportant information of the interaction between proteins, has been established. Topredict the modules which have notable biological function by using protein-proteininteraction network data is of great significance to the research of biological functiongenome.In traditional experiment of biological function modules, the protein-proteininteraction network is always treated as a common network, in which the proteincorresponds to the vertex and the interaction to the edge. Some traditional networkmeasurement, such as The Jaccard coefficient and edge betweenness centrality, isapplied in the research of topological characteristics in protein-protein interactionnetwork. More than to consider only the topological measure of the protein-proteininteraction network, the structural measure is more important to be taken into account,because the network contains abundant biological structure. In this article, ameasurement called DS (Degree-Symmetry) based on the symmetric structures is raised.In the foundation of this measurement, the relationship among DS, weak tiesphenomenon and the topological similarity in protein-protein interaction network isstudied. A reliable virtual network is built by symmetric measurement DS. What is more,a "core-attachment" test method of biological function modules is put forward.An experiment based on data of protein-protein interaction network is performed.The results show that symmetric measurement DS can describe the weak tiesphenomenon in the protein-protein interaction network more precisely than traditionalnetwork measurement. In addition, biological function modules detected by virtualnetwork are more accurate, and outstanding in biological significance.