Reversible thermal denaturation of human FGF-1 induced by low concentrations of guanidine hydrochloride.


Human acidic fibroblast growth factor (FGF-1) is a powerful mitogen and angiogenic factor with an apparent melting temperature (Tm) in the physiological range. FGF-1 is an example of a protein that is regulated, in part, by stability-based mechanisms. For example, the low Tm of FGF-1 has been postulated to play an important role in the unusual endoplasmic reticulum-independent secretion of this growth factor. Despite the close relationship between function and stability, accurate thermodynamic parameters of unfolding for FGF-1 have been unavailable, presumably due to effects of irreversible thermal denaturation. Here we report the determination of thermodynamic parameters of unfolding (DeltaH, DeltaG, and DeltaCp) for FGF-1 using differential scanning calorimetry (DSC). The thermal denaturation is demonstrated to be two-state and reversible upon the addition of low concentrations of added guanidine hydrochloride (GuHCl). DeltaG values from the DSC studies are in excellent agreement with values from isothermal GuHCl denaturation monitored by fluorescence and circular dichroism (CD) spectroscopy. Furthermore, the results indicate that irreversible denaturation is closely associated with the formation of an unfolding intermediate. GuHCl appears to promote reversible two-state denaturation by initially preventing aggregation of this unfolding intermediate, and at subsequently higher concentrations, by preventing formation of the intermediate. Study holds ProTherm entries: 5504, 5505, 5506 Extra Details:

Submission Details

ID: pdhtiUFk3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:30 p.m.

Version: 1

Publication Details
Blaber SI;Culajay JF;Khurana A;Blaber M,Biophys. J. (1999) Reversible thermal denaturation of human FGF-1 induced by low concentrations of guanidine hydrochloride. PMID:10388772
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 Fibroblast growth factor 2 P09038 FGF2_HUMAN
100.0 Fibroblast growth factor 2 Q5IS69 FGF2_PANTR
98.7 Fibroblast growth factor 2 P03969 FGF2_BOVIN
98.1 Fibroblast growth factor 2 P20003 FGF2_SHEEP
97.3 Fibroblast growth factor 2 P13109 FGF2_RAT
96.6 Fibroblast growth factor 2 P15655 FGF2_MOUSE
92.9 Fibroblast growth factor 2 P48798 FGF2_MONDO
92.2 Fibroblast growth factor 2 P48800 FGF2_CHICK
99.3 Fibroblast growth factor 2 P48799 FGF2_RABIT
91.1 Fibroblast growth factor 2 Q60487 FGF2_CAVPO