Proline inhibits aggregation during protein refolding

Citation
D. Samuel et al., Proline inhibits aggregation during protein refolding, PROTEIN SCI, 9(2), 2000, pp. 344-352
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
PROTEIN SCIENCE
ISSN journal
0961-8368 → ACNP
Volume
9
Issue
2
Year of publication
2000
Pages
344 - 352
Database
ISI
SICI code
0961-8368(200002)9:2<344:PIADPR>2.0.ZU;2-G
Abstract
The in vitro refolding of hen egg-white lysozyme is studied in the presence of various osmolytes. Proline is found to prevent aggregation during prote in refolding. However, other osmolytes used in this study fail to exhibit a similar property. Experimental evidence suggests that proline inhibits pro tein aggregation by binding to folding intermediate(s) and trapping the fol ding intermediate(s) into enzymatically inactive, "aggregation-insensitive" state(s). However, elimination of proline from the refolded protein mixtur e results in significant recovery of the bacteriolytic activity. Al higher concentrations (>1.5 M), proline is shown to form loose, higher-order molec ular aggregate(s). The supramolecular assembly of proline is found to posse ss an amphipathic character. Formation of higher-order aggregates is believ ed to be crucial for proline to function as a protein folding aid. In addit ion to its role in osmoregulation under water stress conditions, the result s of this study hint at the possibility of proline behaving as a protein fo lding chaperone.