On Complex Network Properties Of Drug-target Interaction Network Generated From Multiple Open Databases

Many complex systems can be analysed and studied by the network analysis method, such as the social relationship network, food chain network, genetic network, and metabolic network, etc. The successful application of the network method in natural science and social science fields, has helped people to extend the knowledge of some complex networks, and obtain plenty of important achievements. In fact, a cell system is a complicated molecular network, in which the interaction of proteins、 DNAs、 metabolic products and other small molecules makes the cell properly fulfill its function. The curative effect or side-effect of a drug may be interpreted as the drug’s regulation in the internal complex molecular network of living being. From this standpoint, drug becomes a part of the complex molecular network in cells. Evaluating the efficacy and side-effect in the big network background would help people to extend the vision of pharmacological researching. The idea of this paper is to treat the existing information of drug-target interactions as a real drug-target model of interaction network, trying to construct a drug-target network by constructing an appropriate database, and to sum up the drug-target interactions law by using the complex network theory. According to this goal, the work has been done in two areas on the one hand, we have integrateed some public database resources, such as RCSB、 SCOP、ENZYME and DrugBank etc, and constructed a fully new Protein-Ligand database which can be used in searching and collecting the Protein-ligand interactions information among different databases, And, we have analyzed several representative multi-target ligands’ selectivity about the target. On the other hand, we have constructed a drug-target database based on the Protein-Ligand database and " Role Of Five", and researched the properties of the drug-target network by network theory, such as degree distribution, clustering coefficient, structures of the subnets, small-world property, free scale property etc. In short, structure and properties of the drug-target network were discussed, this work would lay a foundation for the pharmacological research by preliminarily discussing the structure and the properties of the drug-target interaction network from a complex network of perspective.Innovations of this paper:Constructed a new drug-target interactions database based on public databases. This database can not only describe the interaction between the drugs and targets, but also apply3D structures of target points. In addition, after intergrating the SCOP and ENZYME database,it can investigate the Drug-Target interaction by analysing the structure、 function and sequence of the target points.Having researched the Drug-Target interaction network by complex network theory,and analysed the network properties of network, and discovered the power exponent regularity of the drug-target interaction, and researched the subnet structure、 small-world effect scale-free property of this drug-target network.