Partial magic angle spinning NMR 1H, 13C, 15N resonance assignments of the flexible regions of a monomeric alpha-synuclein: conformation of C-terminus in the lipid-bound and amyloid fibril states

• Published in: Biomolecular NMR assignments 2021-10, Vol.15 (2), p.297-303
• Main Authors: Medeiros, Justin, Bamm, Vladimir V., Jany, Catherine, Coackley, Carla, Ward, Meaghan E., Harauz, George, Ryan, Scott D., Ladizhansky, Vladimir
• Format: Article
• Language: English
• Subjects: Biochemistry; Biological and Medical Physics; Biophysics; C-Terminus; Cardiolipin; Dihydroxyphenylalanine; Diphosphatidylglycerol; Fibrils; Lipids; Magnetic resonance spectroscopy; Mitochondria; Movement disorders; Neurodegenerative diseases; NMR; Nuclear magnetic resonance; Parkinson's disease; Phosphocholine; Phospholipids; Physics; Physics and Astronomy; Polymer Sciences; Spectrum analysis; Synuclein; Vesicles
• ISSN: 1874-2718; 1874-270X; 1874-270X
• DOI: 10.1007/s12104-021-10020-z

Alpha-synuclein (α-syn) is a small presynaptic protein that is believed to play an important role in the pathogenesis of Parkinson's disease (PD). It localizes to presynaptic terminals where it partitions between a cytosolic soluble and a lipid-bound state. Recent evidence suggests that α-syn can also associate with mitochondrial membranes where it interacts with a unique anionic phospholipid cardiolipin (CL). Here, we examine the conformation of the flexible fragments of a monomeric α-syn bound to lipid vesicles composed of anionic 1,2-dioleoyl- sn -glycero-3-phosphate (DOPA) and 1,2-dioleoyl- sn -glycero-3-phosphocholine (DOPC) lipids, of tetraoleoyl CL (TOCL) and DOPC, and of fibrils. The dynamic properties of α-syn associated with DOPA:DOPC vesicles were the most favorable for conducting three-dimensional NMR experiments, and the 13 C, 15 N and amide 1 H chemical shifts of the flexible and disordered C-terminus of α-syn could be assigned using three-dimensional through-bond magic angle spinning NMR spectroscopy. Although the C-terminus is more dynamically constrained in fibrils and in α-syn bound to TOCL:DOPC vesicles, a direct comparison of carbon chemical shifts detected using through bond two-dimensional spectroscopy indicates that the C-terminus is flexible and unstructured in all the three samples.