Current Protein and Peptide Science - Volume 17, Issue 1, 2016

Network theory has become an excellent method of choice through which biological data are smoothly integrated to gain insights into complex biological problems. Understanding protein structure, folding, and function has been an important problem, which is being extensively investigated by the network approach. Since the sequence uniquely determines the structure, this review focuses on the networks of non-covalently Read More

In this work, we present an extensive analysis of protein contact network topology applied to a wide data set. We extended the concept of degree distribution to graphlets, describing local connectivity patterns. We compared results to those derived from artificial networks of the same size (number of nodes), reproducing the average degree of each protein network. The artificial networks resemble the coiling of immaterial Read More

Protein homodimers pose some intriguing questions about the relation between structure and stability. We approached the problem by means of a topological methodology based on protein contact networks. We correlated local interface descriptors with structure and energy global properties of the systems under analysis. We demonstrated that the graph energy, formerly applied to the analysis of unconjugated hydrocarbons Read More

Proteins can be conveniently represented as networks of interacting residues, thus allowing the study of several network parameters that can shed light onto several of their structural and functional aspects. With respect to the binding of ligands, which are central for the function of many proteins, network analysis may constitute a possible route to assist the identification of binding sites. As the bulk of this review illustrates Read More

Catalytic residues play a significant role in enzyme functions. With the recent accumulation of experimentally determined enzyme 3D structures and network theory on protein structures, the prediction of catalytic residues by amino acid network (AAN, where nodes are residues and links are residue interactions) has gained much interest. Computational methods of identifying catalytic residues are traditionally divided into two Read More

A systematic comparison with the Wild-Type (WT) of one-point mutants of bacteriophage T4 lysozyme was carried out using as difference markers the topological parameters of the protein contact networks corresponding to each crystallographic structure. The investigation concerned changes at the resolution level of single residue along the protein sequence. The results were correlated with (reported) changes in functional pr Read More

Protein structures can be conceptualized as context-aware self-organizing systems. One of its emerging properties is a modular architecture. Such modular architecture has been identified as domains and defined as its units of evolution and function. However, this modular architecture is not exclusively defined by domains. Also, the definition of a domain is an ongoing debate. Here we propose differentiating structural, evoluti Read More

Analyzing protein-protein interaction (PPI) networks has been a crucial prerequisite for understanding the molecular basis for most of the diseases. Although several investigations have been carried out on PPI network analysis, none of them explicitly considered binding affinity as a criterion for the analysis. In this work, we have performed a systematic analysis of protein-protein interaction networks in five organisms based on th Read More

Metabolism is a set of fundamental processes that play important roles in a plethora of biological and medical contexts. It is understood that the topological information of reconstructed metabolic networks, such as modular organization, has crucial implications on biological functions. Recent interpretations of modularity in network settings provide a view of multiple network partitions induced by different resolution parameter Read More