Chaperonin GroEL Reassembly: An Effect of Protein Ligands and Solvent Composition
نویسندگان
چکیده
Chaperonin GroEL is a complex oligomeric heat shock protein (Hsp60) assisting the correct folding and assembly of other proteins in the cell. An intriguing question is how GroEL folds itself. According to the literature, GroEL reassembly is dependent on chaperonin ligands and solvent composition. Here we demonstrate dependence of GroEL reassembly efficiency on concentrations of the essential factors (Mg2+, ADP, ATP, GroES, ammonium sulfate, NaCl and glycerol). Besides, kinetics of GroEL oligomerization in various conditions was monitored by the light scattering technique and proved to be two-exponential, which suggested accumulation of a certain oligomeric intermediate. This intermediate was resolved as a heptamer by nondenaturing blue electrophoresis of GroEL monomers during their assembly in the presence of both Mg-ATP and co-chaperonin GroES. Presumably, this intermediate heptamer plays a key role in formation of the GroEL tetradecameric particle. The role of co-chaperonin GroES (Hsp10) in GroEL assembly is also discussed.
منابع مشابه
Disassembly/reassembly strategy for the production of highly pure GroEL, a tetradecameric supramolecular machine, suitable for quantitative NMR, EPR and mutational studies.
GroEL, a prototypical member of the chaperonin class of chaperones, is a large supramocular machine that assists protein folding and plays an important role in proteostasis. GroEL comprises two heptameric rings, each of which encloses a large cavity that provides a folding chamber for protein substrates. Many questions remain regarding the mechanistic details of GroEL facilitated protein foldin...
متن کاملRefolding and reassembly of active chaperonin GroEL after denaturation.
Conditions are reported that, for the first time, permit the folding and assembly of active chaperonin, GroEL, following denaturation in 8 m urea. The folding could be achieved by dilution or dialysis, and the best yields required the simultaneous presence of ammonium sulfate and the Mg2+ complexes of ATP or ADP. Ammonium sulfate was the key to this particular protocol, since there was a small ...
متن کاملGroEL-Assisted Protein Folding: Does It Occur Within the Chaperonin Inner Cavity?
The folding of protein molecules in the GroEL inner cavity under the co-chaperonin GroES lid is widely accepted as a crucial event of GroEL-assisted protein folding. This review is focused on the data showing that GroEL-assisted protein folding may proceed out of the complex with the chaperonin. The models of GroEL-assisted protein folding assuming ligand-controlled dissociation of nonnative pr...
متن کاملPotential for modulation of the hydrophobic effect inside chaperonins.
Despite the spontaneity of some in vitro protein-folding reactions, native folding in vivo often requires the participation of barrel-shaped multimeric complexes known as chaperonins. Although it has long been known that chaperonin substrates fold upon sequestration inside the chaperonin barrel, the precise mechanism by which confinement within this space facilitates folding remains unknown. We...
متن کاملAn Analysis of the Stability, Aggregation Propensity, and Negative Cooperativity of the Escherichia coli Chaperonin GroEL by
Since the discovery of chaperonin GroEL and co-chaperonin GroES, there has been a deluge of literature investigating many aspects of the system. Substrate proteins are protected from aggregation through a cycle of capture, encapsulation, and release made possible through rigid body motions of the GroE system driven by a combination of allosteric controls influenced by nucleotide, potassium and ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 4 شماره
صفحات -
تاریخ انتشار 2014