La brucelosis canina es causa de falla reproductiva y la detección temprana en los perros infectados sigue siendo un desafío. El objetivo del presente estudio fue probar dos antígenos para ser utilizados diferentes inmunoensayos, infección por Brucella canis perros: uno a partir antígeno crudo sonicado RM6/66 (CA-iELISA) otro utilizando proteína inmunodominante GroEL (GroEL-iELISA). Se determin...

Brucellosis is caused by the bacterium Brucella and affects various domestic and wild species. GroEL (Heat Shock Protein 60kDa) as one of the major antigens that stimulate the immune system, increases Brucella survival. The aim of the current study was to clone and express GroEL in Escherichia coli in order to design subunit vaccine. Amplifying was performed using specific primers. The full-len...

Escherichia coli chaperonin GroEL consists of two stacked rings of seven identical subunits each. Accompanying binding of ATP and GroES to one ring of GroEL, that ring undergoes a large en bloc domain movement, in which the apical domain twists upward and outward. A mutant GroEL(AEX) (C138S,C458S,C519S,D83C,K327C) in the oxidized form is locked in a closed conformation by an interdomain disulfi...

Trigger factor (TF) is a putative molecular chaperone recently found to function together with GroEL in the degradation of the fusion protein, CRAG. TF overproduction enhanced the ability of GroEL to form complexes with CRAG, as well as fetuin or histone. To define further this effect on GroEL binding, affinity columns containing a variety of denatured proteins were used. When cell extracts wer...

Many proteins require the assistance of molecular chaperones in order to fold efficiently. Chaperones are known to mask the effects of mutations that induce misfolding because they can compensate for the deficiency in spontaneous folding. One of the best studied chaperones is the eubacterial GroEL/GroES system. In Escherichia coli, three classes of proteins have been distinguished based on thei...

Kinetic analyses of GroE-assisted folding provide a dynamic sequence of molecular events that underlie chaperonin function. We used stopped-flow analysis of various fluorescent GroEL mutants to obtain details regarding the sequence of events that transpire immediately after ATP binding to GroEL and GroEL with prebound unfolded proteins. Characterization of GroEL CP86, a circularly permuted GroE...

Coupling with ATP hydrolysis and cooperating with GroES, the double ring chaperonin GroEL assists the folding of other proteins. Here we report novel GroEL-GroES complexes formed in fluoroberyllate (BeF(x)) that can mimic the phosphate part of the enzyme-bound nucleotides. In ATP, BeF(x) stops the functional turnover of GroEL by preventing GroES release and produces a symmetric 1:2 GroEL-GroES ...

We have studied the interaction of the prototypical chaperonin GroEL with the prion domain of the Het-s protein using solution and solid-state NMR, electron and atomic force microscopies, and EPR. While GroEL accelerates Het-s protofibril formation by several orders of magnitude, the rate of appearance of fibrils is reduced. GroEL remains bound to Het-s throughout the aggregation process and de...

Chaperonin GroEL is an essential molecular chaperone that assists protein folding in the cell. With the aid of cochaperonin GroES and ATP, double ring-shaped GroEL encapsulates non-native substrate proteins inside the cavity of the GroEL-ES complex. Although extensive studies have revealed the outline of GroEL mechanism over the past decade, central questions remain: What are the in vivo substr...

The chaperonin GroEL binds to non-native substrate proteins via hydrophobic interactions, preventing their aggregation, which is minimized at low temperatures. In the present study, we investigated the refolding of urea-denatured rhodanese at low temperatures, in the presence of ox-GroEL (oxidized GroEL), which contains increased exposed hydrophobic surfaces and retains its ability to hydrolyse...