Urea induced unfolding of F isomer of human serum albumin: A case study using multiple probes

Ahmad, Basir; Ankita,; Khan, Rizwan Hasan

doi:10.1016/j.abb.2005.03.013

Cited by 49 publications

(30 citation statements)

References 37 publications

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“…Then, different volumes of the heme-HSA solution (in the absence and presence of the chaotropic agent) were mixed to obtain the desired GnCl concentration at a fixed heme-HSA concentration. GnCl-induced HSA unfolding is fully reversible under the experimental conditions reported in the present study [25][26][27][28][29][30][31][32]. Samples were incubated for 1 h before measurements.…”

Section: Methodsmentioning

confidence: 64%

“…The multidomain structural organization makes HSA a model system to investigate how interdomain interactions could affect the folding/unfolding process [25][26][27][28][29][30][31][32]. With use of different experimental techniques to follow thermal or chaotropic denaturation of HSA, it has been observed that the HSA N state unfolds in two sequential steps, domain II unfolding before domain I (i.e., the heme binding domain) [29][30][31].…”

Section: Introductionmentioning

confidence: 99%

“…With use of different experimental techniques to follow thermal or chaotropic denaturation of HSA, it has been observed that the HSA N state unfolds in two sequential steps, domain II unfolding before domain I (i.e., the heme binding domain) [29][30][31]. Although the guanidinium chloride (GnCl)-induced unfolding of HSA has been reported to proceed cooperatively without any detectable intermediate state in the absence of ligand(s) that would stabilize the intermediate state(s) [30,32], it has been suggested by Rezaei-Tavirani [31] that reversible unfolding of the HSA N form might occur through the formation of an intermediate species, possibly a molten globule, which could retain the ability to bind the heme. A similar mechanism has been proposed for the urea-induced reversible unfolding of the HSA F state [30].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Reversible two-step unfolding of heme–human serum albumin: a 1H-NMR relaxometric and circular dichroism study

Fanali¹,

Sanctis²,

Gioia³

et al. 2008

J Biol Inorg Chem

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Human serum albumin (HSA) participates in heme scavenging, the bound heme turning out to be a reactivity center and a powerful spectroscopic probe. Here, the reversible unfolding of heme-HSA has been investigated by 1 H-NMR relaxometry, circular dichroism, and absorption spectroscopy. In the presence of 6 equiv of myristate (thus fully saturating all available fatty acid binding sites in serum heme-albumin), 1.0 M guanidinium chloride induces some unfolding of heme-HSA, leading to the formation of a folding intermediate; this species is characterized by increased relaxivity and enhanced dichroism signal in the Soret region, suggesting a more compact heme pocket conformation. Heme binds to the folding intermediate with

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Section: Methodsmentioning

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reversible two-step unfolding of heme–human serum albumin: a 1H-NMR relaxometric and circular dichroism study

Fanali¹,

Sanctis²,

Gioia³

et al. 2008

J Biol Inorg Chem

View full text Add to dashboard Cite

show abstract

“…Partial unfolding in solution has been observed from increased temperature, from adding denaturants such as urea or GdnHCl, and at extremes in pH [29,30] and on HIC surfaces [31][32][33]. Chemical denaturation and the mechanism of surface unfolding are not as well understood as are thermal and pH induced denaturation in solution.…”

Section: Relating Partially Unfolded States In Solution and On Chromamentioning

confidence: 97%

Structures of multidomain proteins adsorbed on hydrophobic interaction chromatography surfaces

Gospodarek

Sun

O’Connell

et al. 2014

Journal of Chromatography A

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“…Similar observations were made in other proteins during chemical denaturation. 10,11 Far-UV CD: The far-UV CD studies on LEF4 protein were performed to assess the effect of the denaturant (GnHCl) on the secondary structure of the protein. The spectra obtained for the protein in the absence and presence of 0.2M, 0.5M, 1M, 2M, and 6M GnHCl concentrations are depicted in Figure 5.…”

Section: Gnhcl Induced Denaturationmentioning

confidence: 99%

Biophysical characterization and unfolding of LEF4 factor of RNA polymerase from AcNPV

et al. 2009

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Late expression factor 4 (LEF4) is one of the four subunits of Autographa californica nuclear polyhedrosis virus (AcNPV) RNA polymerase. LEF4 was overexpressed in Escherichia coli and recombinant protein was subjected to structural characterization. Chemical induced unfolding of LEF4 was investigated using intrinsic fluorescence, hydrophobic dye binding, fluorescence quenching, and circular dichroism (CD) techniques. The unfolding of LEF4 was found to be a non-two state, biphasic transition. Intermediate states of LEF4 at 2M GnHCl and 4M urea shared some common structural features and hence may lie on the same pathway of protein folding. Steady-state fluorescence and far-UV CD showed that while there was considerable shift in the wavelength of emission maximum (lambda(max)), the secondary structure of LEF4 intermediates at 2M GnHCl and 4M urea remained intact. Further, temperature induced denaturation of LEF4 was monitored using far-UV CD. This study points to the structural stability of LEF4 under the influence of denaturants like urea and temperature. Although LEF4 is an interesting model protein to study protein folding intermediates, in terms of functional significance the robust nature of this protein might reflect one of the several strategies adapted by the virus to survive under very adverse environmental and physiological conditions.

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Urea induced unfolding of F isomer of human serum albumin: A case study using multiple probes

Cited by 49 publications

References 37 publications

Reversible two-step unfolding of heme–human serum albumin: a 1H-NMR relaxometric and circular dichroism study

Reversible two-step unfolding of heme–human serum albumin: a 1H-NMR relaxometric and circular dichroism study

Structures of multidomain proteins adsorbed on hydrophobic interaction chromatography surfaces

Biophysical characterization and unfolding of LEF4 factor of RNA polymerase from AcNPV

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