Hsp93 Atpase
Hsp93 Atpase - Related Videos
07:38
Measuring In Vitro ATPase Activity for Enzymatic Characterization
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Cited by 27 •
2016
We describe a basic protocol for quantitating in vitro ATPase activity. This protocol can be optimized based on the level of activity and requirements for a given purified ATPase.
11:07
Biochemical Reconstitution of Steroid Receptor•Hsp90 Protein Complexes and Reactivation of Ligand Binding
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Cited by 1 •
2011
An in vitro method for preparing functional glucocorticoid receptor (GR)•hsp90 protein complexes from purified proteins and cellular lysates is described. The method utilizes immunoadsorption of recombinant GR followed by salt-stripping and protein complex reconstitution. The importance of cofactors and buffer conditions are discussed, as are potential method applications.
08:44
Isolation of F1-ATPase from the Parasitic Protist Trypanosoma brucei
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Cited by 1 •
2019
This protocol describes the purification of F1-ATPase from the cultured insect stage of Trypanosoma brucei. The procedure yields a highly pure, homogeneous, and active complex suitable for structural and enzymatic studies.
12:07
Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET
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2021
ANS binds to the Ca2+-ATPase recombinant N-domain. Fluorescence spectra display a FRET-like pattern upon excitation at a wavelength of 295 nm. NBS-mediated chemical modification of Trp quenches the fluorescence of the N-domain, which leads to the absence of energy transfer (FRET) between the Trp residue and ANS.
08:37
Purification of the Sarco-Endoplasmic Reticulum Ca2+-ATPase from Rabbit Muscle
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2025
This protocol describes an improved SERCA purification method, which includes the disaccharide trehalose in the final centrifugation step. This carbohydrate stabilizes proteins under harsh conditions. The purified SERCA was catalytically active and displayed high purity, making it suitable for structural and functional studies.
FAQs
The two conserved ATPase domains provide Hsp93 with the machinery to bind and hydrolyze ATP. Their activity links chemical energy to changes in the chaperone’s conformation, allowing it to act on client proteins rather than merely bind them. This domain organization is therefore central to both protein remodeling and the movement of substrates through associated molecular complexes.
ATP hydrolysis is important because it converts a nucleotide-binding event into mechanical work. In Hsp93, that energy can produce conformational changes that remodel client proteins or help drive their movement through associated complexes. The outcome depends on the molecular task: remodeling supports handling of protein conformations, whereas translocation uses the same energy conversion to promote passage through a protein-import system.
Within the Clp protease system, Hsp93 contributes an unfolding step before degradation. This is significant because selected substrates must be unfolded for the protease machinery to process them. Hsp93 therefore connects ATP-powered remodeling with selective protein turnover, helping explain how chloroplast proteostasis can remove particular proteins through an organized degradation pathway.
Hsp93 can direct its ATP-dependent activity toward different outcomes depending on the complex with which it works. In the Clp system, remodeling prepares selected substrates for degradation; during chloroplast protein translocation, conformational changes help drive protein movement. This context-dependent activity allows one chaperone system to support both quality control and trafficking.
During chloroplast protein import, Hsp93 participates in protein translocation, using ATP-linked conformational changes to help drive movement through associated complexes. This role places the ATPase at a functional connection between energy-dependent molecular remodeling and delivery of proteins into the organelle. It consequently contributes to chloroplast maintenance and the broader process of organelle biogenesis.
Hsp93 is relevant to plant development because chloroplasts require reliable protein import, quality control, and degradation. By contributing to these processes, the ATPase supports the protein-handling activities needed for organelle biogenesis. Its importance therefore extends beyond an individual substrate or complex, since chloroplast proteostasis can influence cellular functions associated with plant growth and development.