Revisiting macromolecular hydration with HullRadSAS

Hydration of biological macromolecules is important for their stability and function. Historically, attempts have been made to describe the degree of macromolecular hydration using a single parameter over a narrow range of values. Here, we describe a method to calculate two types of hydration: surface shell water and entrained water. A consideration of these two types of hydration helps to explain the hydration problem in hydrodynamics. The combination of these two types of hydration allows accurate calculation of hydrodynamic volume and related macromolecular properties such as sedimentation and diffusion coefficients, intrinsic viscosities, and the concentration-dependent non-ideality identified with sedimentation velocity experiments.

Automated summary

Hydration of biological macromolecules is crucial for their stability and function. Traditional approaches to describe macromolecular hydration using a single parameter have limitations. This study presents a method to calculate two types of hydration: surface shell water and entrained water, which helps explain the hydration problem in hydrodynamics. The combination of these two types of hydration allows accurate calculation of hydrodynamic volume and various macromolecular properties.