Veinger, Lea and Diamant, Sophia and Buchner, Johannes and Goloubinoff, Pierre (1998) The small heat-shock protein IbpB from Escherichia coli stabilizes stress-denatured proteins for subsequent refolding by a multichaperone network. JOURNAL OF BIOLOGICAL CHEMISTRY, 273 (18). pp. 11032-11037. ISSN 0021-9258, 1083-351X
Full text not available from this repository. (Request a copy)Abstract
The role of small heat-shock proteins in Escherichia coli is still enigmatic. We show here that the small heat-shock protein IbpB is a molecular chaperone that assists the refolding of denatured proteins in the presence of other chaperones. IbpB oligomers bind and stabilize heat-denatured malate dehydrogenase (MDH) and ureadenatured lactate dehydrogenase and thus prevent the irreversible aggregation of these proteins during stress. While IbpB-stabilized proteins alone do not refold spontaneously, they are specifically delivered to the DnaK/DnaJ/GrpE (KJE) chaperone system where they refold in a strict ATPase-dependent manner. Although GroEL/GroES (LS) chaperonins do not interact directly with IbpB-released proteins, LS accelerate the rate of KJE-mediated refolding of IbpB-released MDH, and to a lesser extent lactate dehydrogenase, by rapidly processing KJE-released early intermediates. Kinetic and gelfiltration analysis showed that denatured MDH preferentially transfers from IbpB to KJE, then from KJE to LS, and then forms a active enzyme. IbpB thus stabilizes aggregation-prone folding intermediates during stress and, as an integral part of a cooperative multichaperone network, is involved in the active refolding of stress-denatured proteins.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | AUTOFLUORESCENT ASTROCYTIC INCLUSIONS; MOLECULAR CHAPERONE; ALPHA-CRYSTALLIN; EXPRESSION; GROWTH; CELLS; DNAK |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 24 Feb 2023 08:59 |
| Last Modified: | 24 Feb 2023 08:59 |
| URI: | https://pred.uni-regensburg.de/id/eprint/49845 |
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