Signatures of currency vertices

TL;DR

This paper introduces the concept of currency vertices in networks, extending the idea of currency metabolites, and analyzes their structural roles across various real-world networks like metabolic, music collaboration, and email exchange networks.

Contribution

It generalizes the concept of currency metabolites to currency vertices and examines their structural significance in diverse network systems.

Findings

Currency vertices are present in metabolic, music, and email networks.

Network structures reveal division into currency vertices and others.

Currency vertices play key roles in network functionality.

Abstract

Many real-world networks have broad degree distributions. For some systems, this means that the functional significance of the vertices is also broadly distributed, in other cases the vertices are equally significant, but in different ways. One example of the latter case is metabolic networks, where the high-degree vertices -- the currency metabolites -- supply the molecular groups to the low-degree metabolites, and the latter are responsible for the higher-order biological function, of vital importance to the organism. In this paper, we propose a generalization of currency metabolites to currency vertices. We investigate the network structural characteristics of such systems, both in model networks and in some empirical systems. In addition to metabolic networks, we find that a network of music collaborations and a network of e-mail exchange could be described by a division of the vertices into currency vertices and others.