The fragility of protein-protein interaction networks

¹ Computational Physics, IfB, ETH Zurich - Schafmattstrasse 6, 8093 Zurich, Switzerland
² Instituto de Física, Universidade Federal da Bahia - 40210-210, Salvador, Brazil
³ Biomedical Engineering, Rutgers University - Piscataway, NJ, USA
⁴ Departamento de Física, Universidade Federal do Ceará - 60451-970 Fortaleza, Ceará, Brazil

^a schnechr@ethz.ch

Received: 15 February 2011
Accepted: 13 May 2011

Abstract

The capacity to resist perturbations from the environment is crucial to the survival of all organisms. We quantitatively analyze the susceptibility of protein interaction networks of numerous organisms to random and targeted failures. We find for all organisms studied that random rewiring improves protein network robustness, so that actual networks are more fragile than rewired surrogates. This unexpected fragility contrasts with the behavior of networks such as the Internet, whose robustness decreases with random rewiring. We trace this surprising effect to the modular structure of protein networks.