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Poly‐ L ‐lysine enhances the protein disaggregation activity of ClpB
Author(s) -
Strub Christine,
Schlieker Christian,
Bukau Bernd,
Mogk Axel
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00985-2
Subject(s) - clpb , chaperone (clinical) , lysine , biochemistry , aaa proteins , atpase , chemistry , casein , effector , protein aggregation , biology , biophysics , enzyme , heat shock protein , amino acid , medicine , pathology , gene
The Hsp100 protein ClpB is a member of the AAA+ protein family that mediates the solubilization of aggregated proteins in cooperation with the DnaK chaperone system. Unstructured polypeptides such as casein or poly‐ L ‐lysine have been shown to stimulate the ATPase activity of ClpB and thus may both act as substrates. Here we compared the effects of α‐casein and poly‐ L ‐lysine on the ATPase and chaperone activities of ClpB. α‐Casein stimulated ATP hydrolysis by both AAA domains of ClpB and inhibited the ClpB‐dependent solubilization of aggregated proteins if present in excess. In contrast, poly‐ L ‐lysine stimulated exclusively the ATPase activity of the second AAA domain and increased the disaggregation activity of ClpB. Thus poly‐ L ‐lysine does not act as substrate, but rather represents an effector molecule, which enhances the chaperone activity of ClpB.