Table 1.
Basic definitions in PPI network
| Term | Definition |
|---|---|
| Node or (Vertices) | Each protein in network |
| Edge or (link) | Physical or functional interactions between proteins |
| Hub | Each “high-degree” node of a network |
| Modules | Group of sub networks in which each sub network includes a high number of inside-sub network links and a low number of between- sub network links |
| Degree (k) | The number of adjacent links |
| Average degree (<k> ) | The mean of all degree values of nodes in a network. |
| Clustering Coefficient (<C> ) | The proportion of links between the nodes within the i-neighborhood divided by the number of links that could possibly exist between them |
| Shortest Path Length | The steps (number of links) needed to connect every pair of nodes through their shortest path. |
| Diameter | The minimum number of links that separate the two most distant nodes in a network. |
| Betweenness centrality | Measures how often nodes occur on the shortest paths between other nodes |
| Heterogeneity of a network | the coefficient of variation of the degree distribution |