Folding and Stabilization of Native-Sequence-Reversed Proteins.

Area of Science:

• Biophysics
• Computational Biology
• Protein Science

Background:

• The protein folding problem, determining a protein's 3D structure from its amino acid sequence, is complex.
• The folding behavior of reversed native protein sequences remains largely uninvestigated.
• Native protein sequences possess inherent properties that facilitate folding, unlike random sequences.

Purpose of the Study:

• To explore the folding capabilities of reversed native protein sequences.
• To analyze how protein size and hydrophobic core flexibility influence reverse-sequence folding.
• To develop strategies for guiding the folding of reverse sequences that fail to adopt native-like structures.

Main Methods:

• Utilized a tandem protein structure prediction algorithm.
• Employed molecular dynamics simulations to analyze folding pathways.
• Investigated small proteins of increasing structural complexity (alpha-helix, beta-hairpin, alpha-helix bundle, alpha/beta-protein).
• Applied a mutational strategy for beta-hairpins that failed to fold.

Main Results:

• Reverse sequences' ability to form native-like folds depends significantly on protein size.
• Hydrophobic core flexibility is a critical factor in successful reverse-sequence folding.
• Insertion of amino acids into the beta-turn region can guide stable beta-hairpin formation in reverse sequences.

Conclusions:

• Reverse protein sequences exhibit distinct folding behaviors compared to random sequences.
• Protein sequence-structure mapping is influenced by sequence directionality.
• Findings may inform novel protein design and structure prediction methodologies.