General Characterization of Properties of Ordered and Disordered Proteins by Wide-Line 1H NMR

TL;DR

This paper uses wide-line 1H NMR to study how hydration water differs between ordered and disordered proteins, helping distinguish their structural properties.

Contribution

It introduces a method to quantify protein disorder using hydration shell properties measured by NMR.

Findings

Disordered proteins bind water more strongly than globular proteins.

Melting diagrams of hydration water reveal structural differences between protein types.

The amount and heterogeneity of mobile hydration water correlate with disorder levels.

Abstract

Wide-line 1H NMR is an efficient spectroscopic
method
to determine the disorder tendency of a protein. It directly measures
the properties of the hydration shell of proteins, delivering exact
and measurable values of their disorder/order content. A comparison
is performed between several globular and disordered proteins. The
common properties of the subzero mobile hydration water of these two
groups were investigated. The amount of the mobile hydration water
and the shape of the melting diagram at subzero temperatures together
provide a possibility to distinguish globular proteins from disordered
proteins. The shape of the melting diagram also gives information
about the presence of secondary structural elements. The disordered
and globular protein regions′ fundamentally different structures
are reflected in their melting diagrams, allowing one to directly
determine the level of disorder in a specific protein structure. Intrinsically
disordered proteins bind water more strongly than globular proteins,
which is shown by the somewhat higher temperature values where mobile
hydration water first appears but with a significantly higher heterogeneity
in the energy distributions of protein–water interactions.

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