The neuroendocrine protein 7B2 is intrinsically disordered

Area of Science:

• Biochemistry
• Molecular Biology
• Neuroendocrinology

Background:

• The protein 7B2 is crucial for the maturation of proprotein convertase 2 (proPC2).
• 7B2 also functions as a postfolding chaperone, inhibiting the aggregation of proteins like α-synuclein.

Purpose of the Study:

• To elucidate the mechanism by which 7B2 prevents protein aggregation.
• Investigate the structural properties of 7B2 and its role in chaperone activity.

Main Methods:

• Gel filtration chromatography
• Intrinsic tryptophan fluorescence
• ANS binding assays
• Circular dichroism (CD) spectroscopy
• Nuclear magnetic resonance (NMR) spectroscopy

Main Results:

• 7B2 exists as an extended monomer but can oligomerize in a concentration-dependent manner.
• Both full-length and truncated 7B2 forms exhibit minimal secondary structure.
• NMR revealed a disorder-to-order transition in 7B2 upon interaction with α-synuclein.

Conclusions:

• 7B2 is a natively disordered protein.
• Its lack of secondary structure and tendency to oligomerize facilitate its function as an anti-aggregation chaperone.