An automated QM/MM average protein electrostatic configuration approach for flavoproteins: APEC-F 2.0

Area of Science:

• Biochemistry
• Computational Chemistry
• Structural Biology

Background:

• Flavoproteins are crucial redox proteins utilizing a flavin cofactor for diverse functions.
• Computational modeling often uses hybrid quantum mechanical/molecular mechanical (QM/MM) methods for flavoproteins.
• Existing QM/MM methods present a trade-off between accuracy of flavin electronic structure and protein dynamics sampling.

Purpose of the Study:

• To present APEC-F 2.0, an automated QM/MM workflow for constructing flavoprotein models.
• To facilitate systematic studies of flavin cofactor properties in various states.
• To enable comparative analyses across different flavoproteins and conditions.

Main Methods:

• Developed an automated QM/MM workflow (APEC-F 2.0) using open-source software.
• Employed a hybrid QM/MM approach with quantum mechanical treatment for the flavin cofactor.
• Utilized molecular dynamics to generate a superposition of protein configurations for a static molecular mechanics environment.

Main Results:

• The APEC-F 2.0 workflow automates the construction of QM/MM models for flavoproteins.
• The method leverages the flavin isoalloxazine ring's rigidity for efficient geometry optimization.
• The workflow enables systematic comparison of flavin spectral, electronic, and chemical properties.

Conclusions:

• APEC-F 2.0 offers a standardized and efficient approach for QM/MM modeling of flavoproteins.
• This tool simplifies the investigation of flavin cofactor behavior in different redox, protonation, and excited states.
• The automation facilitates broader research into the diverse roles of flavoproteins.