Rescue of the neuroblastoma mutant of the human nucleoside diphosphate kinase A/nm23-H1 by the natural osmolyte trimethylamine-N-oxide.
The point mutation S120G in human nucleoside diphosphate kinase A, identified in patients with neuroblastoma, causes a protein folding defect. The urea-unfolded protein cannot refold in vitro, and accumulates as a molten globule folding intermediate. We show here that the trimethylamine-N-oxide (TMAO) corrects the folding defect and stimulated subunit association. TMAO also substantially increased the stability to denaturation by urea of both wild-type and S120G mutant. A non-native folding intermediate accumulated in the presence of 4.5-7M urea and of 2M TMAO. It was inactive, monomeric, contained some secondary structure but no tertiary structure and displayed a remarkable stability to denaturation.
Georgescauld
Florian
F
Institut de Biochimie et Génétique Cellulaires, University of Bordeaux-2, CNRS, 1 Rue C. Saint-Saëns, 33077 Bordeaux Cedex, France.
Mocan
Iulia
I
Lacombe
Marie-Lise
ML
Lascu
Ioan
I
D004305:Dose-Response Relationship, Drug; D006801:Humans; D007700:Kinetics; D008744:Methylamines / Q000378:metabolism*; D054778:NM23 Nucleoside Diphosphate Kinases / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009447:Neuroblastoma / Q000235:genetics*; D017354:Point Mutation; D017510:Protein Folding / Q000187:drug effects; D014508:Urea / Q000494:pharmacology
D008744:Methylamines; D054778:NM23 Nucleoside Diphosphate Kinases; D009363:Neoplasm Proteins; D014508:Urea; C517938:NME1 protein, human; C005855:trimethyloxamine