title: Chaperone and antichaperone activities of trigger factor.
abstract: Reduced denatured lysozyme tends to aggregate at neutral pH and competition between productive folding and aggregation substantially reduces the efficiency of refolding. Trigger factor, a folding catalyst and chaperone can, depending on the concentration of trigger factor and the solution conditions, cause either a substantial increase (chaperone activity) or a substantial decrease (antichaperone activity) in the recovery of native lysozyme as compared with spontaneous refolding. When trigger factor is working as a chaperone, the reactivation rates of lysozyme are decelerated and aggregation decreases with increasing trigger factor concentrations. Under conditions where antichaperone activity of trigger factor dominates, the reactivation rates of lysozyme are accelerated and aggregation is increased. Trigger factor and lysozyme were both released from the aggregates on re-solubilization with urea indicating that trigger factor participates directly in aggregate formation and is incorporated into the aggregates. The apparently dual effect of trigger factor toward refolding of lysozyme is a consequence of the peptide binding ability and may be important in regulation of protein biosynthesis.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing, China.
authors.forename: Guo-Chang
authors.initials: GC
authors.lastname: Huang
authors.forename: Jia-Jia
authors.initials: JJ
authors.lastname: Chen
authors.forename: Chuan-Peng
authors.initials: CP
authors.lastname: Liu
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Zhou
mesh_terms: D002021:Buffers; D029968:Escherichia coli Proteins / Q000378:metabolism*; D019855:Ethylene Glycol / Q000378:metabolism; D006531:HEPES; D018832:Molecular Chaperones / Q000378:metabolism*; D009113:Muramidase / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D011489:Protein Denaturation; D017510:Protein Folding; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D002021:Buffers; D029968:Escherichia coli Proteins; D018832:Molecular Chaperones; D010710:Phosphates; D012965:Sodium Chloride; D009113:Muramidase; C403324:trigger factor, E coli; D019696:Peptidylprolyl Isomerase; D019855:Ethylene Glycol; D006531:HEPES