Glycosylation inhibits the interaction of invertase with the chaperone GroEL.
During refolding and reassociation of chemically denatured non-glycosylated invertase from Saccharomyces cerevisiae, aggregation competes with correct folding, leading to low yields of reactivation (Kern et al. (1992) Protein Sci. 1, 120-131). In the presence of the chaperone GroEL, refolding is completely arrested. This suggests the formation of a stable complex between GroEL and non-native non-glycosylated invertase. Addition of MgATP results in a slow release of active invertase from the chaperone complex. When GroEL/ES and MgATP are present during refolding, the final reactivation yield increases from 14% to 36%. In contrast, refolding of the core-glycosylated and the high-mannose glycosylated forms of invertase is not arrested by GroEL. Only a short lag phase at the beginning of reactivation and a slightly increased reactivation yield (64% to 86% for core-glycosylated and 62% to 76% for external invertase) indicate a weak interaction of the glycosylated forms with the chaperone.
Institut für Biophysik und Physikalische Biochemie, Universität Regensburg, Germany.
G
G
Kern
M
M
Schmidt
J
J
Buchner
R
R
Jaenicke
D001426:Bacterial Proteins / Q000378:metabolism*; D018834:Chaperonin 60; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006031:Glycosylation; D006360:Heat-Shock Proteins / Q000378:metabolism*; D017510:Protein Folding; D043324:beta-Fructofuranosidase
D001426:Bacterial Proteins; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase