Thermodynamic features of the chemical and thermal denaturations of human serum albumin.


Abstract

The unfolding process of human serum albumin between pH 5.4 and 9.9 was studied by chemical and thermal denaturations. The experimental results showed that there is no correlation between the stability of albumin at different pH values determined by both methods. The free energy change of unfolding versus concentration of guanidine showed a close dependence on the pH, suggesting that the variation of the electrical charge of albumin influences the final state of the unfolded form of the protein. Spectroscopic techniques, such as native fluorescence of the protein and circular dichroism, demonstrated that the unfolded state of the protein obtained from both methods possesses a different helical content. The solvophobic effect and the entropy of the chains have no influence on the final unfolding state when the protein is unfolded by thermal treatment, while, when the protein is unfolded by chemical denaturants, both effects depend on the medium pH. The results indicate that guanidine and urea interact with albumin by electrostatic forces, yielding a randomly coiled conformation in its unfolded state, while thermal denaturation produces a molten globule state and the aggregation of the protein; therefore, both methods yield different structurally unfolded states of the albumin. Study holds ProTherm entries: 12855, 12856, 12857, 12858, 12859, 12860, 12861, 12862, 12863 Extra Details: fatty acids free(<0.005%) albumin; calorimetry; chemical denaturation; fluorescence; thermal unfolding

Submission Details

ID: rYT2wjG9

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:44 p.m.

Version: 1

Publication Details
Farruggia B;Picó GA,Int. J. Biol. Macromol. (1999) Thermodynamic features of the chemical and thermal denaturations of human serum albumin. PMID:10628532
Additional Information

Study Summary

Number of data points 27
Proteins SERUM ALBUMIN ; Serum albumin
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: Cm buffers:acetate: , pH:5.3 ; Experimental Assay: m buffers:acetate: , pH:5.3 ; Experimental Assay: dG_H2O buffers:acetate: , pH:5.3 ; Experimental Assay: Cm pH:7.4, buffers:phosphate: ; Experimental Assay: m pH:7.4, buffers:phosphate: ; Experimental Assay: dG_H2O pH:7.4, buffers:phosphate: ; Experimental Assay: Cm pH:9.9, buffers:glycine: ; Experimental Assay: m pH:9.9, buffers:glycine: ; Experimental Assay: dG_H2O pH:9.9, buffers:glycine: ; Experimental Assay: Cm buffers:acetate: , pH:5.3 ; Experimental Assay: m buffers:acetate: , pH:5.3 ; Experimental Assay: dG_H2O buffers:acetate: , pH:5.3 ; Experimental Assay: Cm pH:7.4, buffers:phosphate: ; Experimental Assay: m pH:7.4, buffers:phosphate: ; Experimental Assay: dG_H2O pH:7.4, buffers:phosphate: ; Experimental Assay: Cm pH:9.9, buffers:glycine: ; Experimental Assay: m pH:9.9, buffers:glycine: ; Experimental Assay: dG_H2O pH:9.9, buffers:glycine: ; Experimental Assay: dCp buffers:acetate: , pH:5.4 ; Experimental Assay: dHcal buffers:acetate: , pH:5.4 ; Experimental Assay: Tm buffers:acetate: , pH:5.4 ; Experimental Assay: dCp pH:7.4, buffers:phosphate: ; Experimental Assay: dHcal pH:7.4, buffers:phosphate: ; Experimental Assay: Tm pH:7.4, buffers:phosphate: ; Experimental Assay: dCp pH:9.9, buffers:glycine: ; Experimental Assay: dHcal pH:9.9, buffers:glycine: ; Experimental Assay: Tm pH:9.9, buffers:glycine:
Libraries Mutations for sequence DAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQEPERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPELLFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFKAWAVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDSISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGMFLYEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLIKQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKRMPCAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFNAETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKADDKETCFAEEGKKLVAASQAALGL

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
1AO6 1997-07-18T00:00:00+0000 2.5 CRYSTAL STRUCTURE OF HUMAN SERUM ALBUMIN
1BJ5 1998-07-02T00:00:00+0000 2.5 HUMAN SERUM ALBUMIN COMPLEXED WITH MYRISTIC ACID
1BKE 1998-07-06T00:00:00+0000 3.15 HUMAN SERUM ALBUMIN IN A COMPLEX WITH MYRISTIC ACID AND TRI-IODOBENZOIC ACID
1BM0 1998-07-28T00:00:00+0000 2.5 CRYSTAL STRUCTURE OF HUMAN SERUM ALBUMIN
1E78 2000-08-25T00:00:00+0000 2.6 Crystal structure of human serum albumin
1E7A 2000-08-26T00:00:00+0000 2.2 Crystal structure of human serum albumin complexed with the general anesthetic propofol
1E7B 2000-08-26T00:00:00+0000 2.38 Crystal structure of human serum albumin complexed with the general anesthetic halothane
1E7C 2000-08-26T00:00:00+0000 2.4 HUMAN SERUM ALBUMIN COMPLEXED WITH MYRISTIC ACID and the general anesthetic halothane
1E7E 2000-08-29T00:00:00+0000 2.5 HUMAN SERUM ALBUMIN COMPLEXED WITH DECANOIC ACID (CAPRIC ACID)
1E7F 2000-08-29T00:00:00+0000 2.43 HUMAN SERUM ALBUMIN COMPLEXED WITH DODECANOIC ACID (LAURIC ACID)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
93.7 Serum albumin Q28522 ALBU_MACMU
93.7 Serum albumin A2V9Z4 ALBU_MACFA
98.5 SERUM ALBUMIN Q5NVH5 ALBU_PONAB
100.0 SERUM ALBUMIN P02768 ALBU_HUMAN