Reconstitution of a heat shock effect in vitro: influence of GroE on the thermal aggregation of alpha-glucosidase from yeast.
alpha-Glucosidase from yeast is inactivated rapidly at temperatures above 42 degrees C. The thermal inactivation is accompanied by aggregation. The molecular chaperone GroEL suppresses the formation of aggregates by binding the thermally inactivated alpha-glucosidase. Spectroscopic studies suggest that GroEL binds alpha-glucosidase in an intermediately folded state. The complex between alpha-glucosidase and GroEL can be dissolved by MgATP. GroES accelerates the MgATP-dependent dissociation of the alpha-glucosidase-GroEL complex. At elevated temperatures this release leads to the formation of aggregates, while at lower temperatures native, enzymatically active molecules are formed.
Höll-Neugebauer
B
B
Biochemical Research Center, Boehringer Mannheim GmbH, Penzberg, Germany.
Rudolph
R
R
Schmidt
M
M
Buchner
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D018833:Chaperonins; D004789:Enzyme Activation; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D011487:Protein Conformation; D011489:Protein Denaturation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013057:Spectrum Analysis; D000520:alpha-Glucosidases / Q000378:metabolism*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C028715:GroE protein, E coli; D006360:Heat-Shock Proteins; D000255:Adenosine Triphosphate; D000520:alpha-Glucosidases; D018833:Chaperonins