C-mannosylation supports folding and enhances stability of thrombospondin repeats.
Elife
; 82019 12 23.
Article
in En
| MEDLINE
| ID: mdl-31868591
ABSTRACT
Previous studies demonstrated importance of C-mannosylation for efficient protein secretion. To study its impact on protein folding and stability, we analyzed both C-mannosylated and non-C-mannosylated thrombospondin type 1 repeats (TSRs) of netrin receptor UNC-5. In absence of C-mannosylation, UNC-5 TSRs could only be obtained at low temperature and a significant proportion displayed incorrect intermolecular disulfide bridging, which was hardly observed when C-mannosylated. Glycosylated TSRs exhibited higher resistance to thermal and reductive denaturation processes, and the presence of C-mannoses promoted the oxidative folding of a reduced and denatured TSR in vitro. Molecular dynamics simulations supported the experimental studies and showed that C-mannoses can be involved in intramolecular hydrogen bonding and limit the flexibility of the TSR tryptophan-arginine ladder. We propose that in the endoplasmic reticulum folding process, C-mannoses orient the underlying tryptophan residues and facilitate the formation of the tryptophan-arginine ladder, thereby influencing the positioning of cysteines and disulfide bridging.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Folding
/
Receptors, Cell Surface
/
Thrombospondins
/
Caenorhabditis elegans Proteins
/
Mannose
/
Membrane Proteins
Limits:
Animals
Language:
En
Journal:
Elife
Year:
2019
Document type:
Article
Affiliation country: