The reliability of the degree distribution of protein-protein interaction network in different species

Protein-protein interaction (PPI) networks play a vital role in living cells. The possible error and bias in collecting protein-protein interaction network data are mainly factors to influence the reliability of the degree distribution of PPI networks. In this study, three factors including the false positive interaction of the PPI experiments, the different annotating of a protein in different protein databases, and the data newly added in the protein databases are considered as Important influence factors to investigate the degree distribution of PPI networks. The results show that in the present data, the stretched-exponential distribution is the best one for describing the degree distribution of PPI networks and it is robust to these factors.