Molecular self-occlusion as a means for accelerating collision cross-section calculations

Abstract

A recent article by Béla Paizs in the International Journal of Mass Spectrometry represents an emerging class of “data-oriented” strategies that pre-organise coordinate data to enable faster collision cross-section calculations, the latter being central for the structural interpretation of ion-mobility spectra. The lack of a closed-form expression for the collision cross-section mandates numerical integration, which risks drawing focus from mathematical inspection and thereby precluding the conception of new means to augment the integration. It can be shown from basic geometry and set theory that, within the projection approximation, molecular self-occlusion provides a “theory-oriented” avenue to more efficient collision cross-section calculations, especially when combined with data-oriented acceleration strategies. This approach is particularly suited for the study of macromolecular assemblies and for protein–protein docking, and may further structural biology applications of ion-mobility spectrometry.