Structural dynamics of neuropeptide hPYY

Area of Science:

• Biophysics
• Computational Biology
• Structural Biology

Background:

• Human Peptide YY (hPYY) is a key neuropeptide Y family member.
• Understanding hPYY's structure is crucial for its biological function.

Purpose of the Study:

• To characterize the ensemble of structures sampled by hPYY.
• To investigate the role of secondary structures in hPYY's function.

Main Methods:

• Experimental techniques: Far UV circular dichroism spectroscopy and Fourier Transform-Infrared measurements.
• Computational methods: 4-μsec molecular dynamics (MD) simulations using AMBER03 potential.
• Validation: Comparison of simulation results with experimental data, including NOE contacts.

Main Results:

• Experimental data confirmed a dominant α-helix secondary structure in hPYY.
• MD simulations with AMBER03 showed excellent agreement with experimental data, predicting a stable C-terminal helix.
• Simulations identified structural fluctuations, including N-terminal motions and partial helix unwinding.

Conclusions:

• The C-terminal helix is essential for the structural integrity of hPYY.
• Simulated structures and motions provide insights into hPYY's biological activity.
• The AMBER03 force field accurately predicted hPYY structure, unlike OPLS-AA.