Abstract
The C-terminal domain (residues 518-803) of the 94 kDa glucose regulated protein (grp94) was expressed in Escherichia coli as a fusion protein with a His6-N-terminal tag (grp94-CT). This truncated form of grp94 formed dimers and oligomers that could be dissociated into monomers by treatment with dithiothreitol. Grp94-CT conferred protection against aggregation on the catalytic subunit of protein kinase CK2 (CK2α), although it did not protect against thermal inactivation. This anti-aggregation effect of grp94-CT was concentration dependent, with full protection achieved at grp94-CT/CK2α molar ratios of 4 : 1. The presence of dithiothreitol markedly reduced the anti-aggregation effects of grp94-CT on CK2α without altering the solubility of the chaperone. It is concluded that the chaperone activity of the C-terminal domain of human grp94 requires the maintenance of its quaternary structure (dimers and oligomers), which seems to be stabilised by disulphide bonds.
Original language | English |
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Pages (from-to) | 429-436 |
Journal | European Journal of Biochemistry |
Volume | 268 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Jan 2001 |
Keywords
- Aggregation
- Chaperone assay
- Protein kinase CK2
- grp94