Impulse-Response Approach to Elastobaric Model for Proteins

TL;DR

This paper introduces the Elastobaric Model (ELM), a new energy landscape model for proteins that explains incoherent elastic neutron scattering data by considering the elastic response of protons and their environment.

Contribution

The paper presents a novel elastobaric coefficient within the ELM, linking elastic potential energy to neutron wave vector transfer and temperature, advancing protein energy landscape modeling.

Findings

ELM successfully explains neutron scattering data for dry proteins.

The elastobaric coefficient relates to universal constants and neutron wave vector.

Data normalization issues are discussed for future testing of ELM.

Abstract

A novel energy landscape model, ELM, for proteins recently explained a collection of incoherent, elastic neutron scattering data from proteins. The ELM of proteins considers the elastic response of the proton and its environment to the energy and momentum exchanged with the neutron. In the ELM, the elastic potential energy is expressed as a sum of a temperature dependent term resulting from equipartition of potential energy among the active degrees of freedom and a wave vector transfer dependent term resulting from the elastic energy stored by the protein during the neutron scattering event. The elastic potential energy involves a new elastobaric coefficient that is proportional to the product of two factors: one factor depends on universal constants and the other on the incident neutron wave vector per degree of freedom. The ELM was tested for dry protein samples with an elastobaric coefficient corresponding to 3 degrees of freedom. A discussion of the data requirements for additional tests of ELM is presented resulting in a call for published data that have not been preprocessed by temperature and wave-vector dependent normalizations.