Structural Characterization of Human Histone H4.1 by Tandem Nonlinear and Linear Ion Mobility Spectrometry...

Area of Science:

• Biochemistry
• Structural Biology
• Biophysics

Background:

• Extracellular histone H4 is implicated in sepsis-induced organ failure, making it a potential drug target.
• In silico drug discovery requires detailed knowledge of histone H4 structural dynamics and 3D coordinates.

Purpose of the Study:

• To characterize the structural dynamics of DNA-free histone H4 type 1 (H4.1) using advanced analytical techniques.
• To provide structural insights for the development of H4.1-targeting drugs.

Main Methods:

• Tandem nonlinear and linear ion mobility spectrometry (FAIMS-TIMS) coupled with mass spectrometry (MS).
• Molecular dynamics (MD) simulations.
• Collision-induced unfolding (CIU) pathway analysis.

Main Results:

• Gas-phase structures of H4.1 are conformationally diverse (compact, partially folded, elongated) and sensitive to initial solution conditions.
• MD simulations generated candidate structures for H4.1 in solution and gas-phase.
• Charge distribution significantly influences the dipole alignment of elongated H4.1 structures in high electric fields.

Conclusions:

• FAIMS-TIMS MS and MD simulations provide critical data on H4.1 structural dynamics and conformational ensembles.
• Understanding these dynamics is essential for rational drug design targeting extracellular histones.