Thermal features of the bovine serum albumin unfolding by polyethylene glycols.


Albumin showed very poor affinity for polyethylene glycol molecular weight (Mw) 1000 (30 M(-1)) and Mw 8000 (400 M(-1)) (PEG 1000 and PEG 8000). Polyethylene glycol of low Mw favours the ionization of the tyrosine (TYR) residues of albumin. Such variation might be a consequence of the change in dielectric constant at the domain of the protein by PEG binding. PEGs of high Mws stabilize the native compact state of human albumin showing negative preferential interaction with the protein. Interaction between PEGs and albumin is thermodynamically unfavourable, and becomes even more unfavourable for denatured proteins whose surface areas are larger than those of native ones leading to a stabilization of the unfolded state, which is manifested as a lowering of the thermal transition temperature. PEG 8000 perturbs the structure of the protein surface, partially modifying the layer of water and the microenvironment of the superficial aromatic residues (tryptophan, TRP and TYR) which is in agreement with the modifications of the UV spectrum of albumin by PEG 8000 and circular dichroism (CD) spectrum at high temperatures. Study holds ProTherm entries: 12940, 12941, 12942, 12943 Extra Details: A thermally induced effect on the ANS fluorescence bound to BSA was monitored.,BSA fatty acids free (<0.005%). ligand: without PEG. polyethylene glycol; albumin; viscosity; protein stability

Submission Details


Submitter: Connie Wang

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

Version: 1

Publication Details
Farruggia B;Nerli B;Di Nuci H;Rigatusso R;Picó G,Int. J. Biol. Macromol. (1999) Thermal features of the bovine serum albumin unfolding by polyethylene glycols. PMID:10520953
Additional Information

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 UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Serum albumin P02769 ALBU_BOVIN
92.4 Serum albumin P14639 ALBU_SHEEP