Physical stabilization of acidic fibroblast growth factor by polyanions.


Acidic fibroblast growth factor (aFGF) is markedly stabilized by heparin. Partially due to the heterogeneity of heparin preparations, the nature of the aFGF polyanion binding site is still ill-defined. We have, therefore, investigated a wide variety of well-defined polyanions in terms of their ability to stabilize human recombinant aFGF (15-154) against thermal denaturation. The specificity of the interaction between aFGF and polyanions is shown to be remarkably weak with a surprising number of polyanions (including small phosphorylated and sulfated compounds as well as highly charged biopolymers) able to induce physical stability. Temperature-dependent fluorescence and circular dichroism measurements show that many of these polyanionic compounds stabilize aFGF to the same extent as heparin. The ability of these agents to protect the three free thiol groups of aFGF from copper-catalyzed oxidation was also explored and significant protection was observed. The extent and electrostatic requirements of the protein's polyanion binding site were probed by the use of a series of well-defined heparin fragments and differentially phosphorylated inositol compounds. A tetrasaccharide fragment of heparin is the smallest unit of heparin capable of stabilizing aFGF against thermal denaturation. Increasing phosphorylation of inositol compounds (up to six phosphate groups per molecule) enhances the thermal stability of aFGF. These results are discussed in the context of a model of human aFGF based on the X-ray crystal structure of the bovine protein and previous studies by others of the heparin binding site of both acidic and basic FGF. Study holds ProTherm entries: 7283 Extra Details:

Submission Details

ID: Co4trqay

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:33 p.m.

Version: 1

Publication Details
Volkin DB;Tsai PK;Dabora JM;Gress JO;Burke CJ;Linhardt RJ;Middaugh CR,Arch. Biochem. Biophys. (1993) Physical stabilization of acidic fibroblast growth factor by polyanions. PMID:7678726
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