Biochemical and Structural Determinants of Protein Folding Disorders: From Chaperones to Aggregates

Background: Protein folding is a tightly regulated biochemical process that ensures the correct three-dimensional conformation necessary for biological function. Disruptions in this process can lead to the accumulation of misfolded proteins and the formation of toxic aggregates, underpinning a wide array of protein folding disorders including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, Huntington’s disease, and systemic amyloidoses. A comprehensive understanding of the molecular determinants that govern folding fidelity and proteostasis is essential for elucidating disease mechanisms and developing targeted therapies. Methods and Results: This review synthesizes data from structural biology, biochemistry, and molecular genetics to dissect the key factors contributing to folding disorders. We explore the role of intrinsic determinants such as primary sequence motifs, hydrophobic patches, and β-sheet propensity in driving misfolding and aggregation. High-resolution structural studies using X-ray crystallography, cryo-EM, and NMR spectroscopy have revealed distinct conformers of pathological aggregates including amyloid fibrils and oligomers, which exert cytotoxic effects through membrane disruption, oxidative stress, and organelle dysfunction. The cellular quality control machinery—comprising molecular chaperones, proteasomes, autophagy systems, and unfolded protein response signaling—plays a central role in maintaining proteome integrity. Dysregulation of these networks contributes to the chronic proteotoxic stress observed in neurodegenerative diseases. Therapeutic strategies targeting folding dynamics include chaperone modulators, aggregation inhibitors, proteostasis regulators, and gene-editing approaches. Conclusion: Protein folding disorders arise from a complex interplay between biochemical predispositions, structural vulnerabilities, and cellular quality control failures. Integrating structural and systems-level insights into folding homeostasis offers a promising roadmap for the rational development of disease-modifying therapies in a broad spectrum of conformational diseases.