scholarly journals Characterization of the interaction between α2-macroglobulin and fibroblast growth factor-2: the role of hydrophobic interactions

2003 ◽  
Vol 374 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Smitha MATHEW ◽  
Sanja ARANDJELOVIC ◽  
Wayne F. BEYER ◽  
Steven L. GONIAS ◽  
Salvatore V. PIZZO
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Hydrophobic Interactions ◽  
Heparan Sulphate ◽  
Fibroblast Growth ◽  
Amino Acid Peptide ◽  
Α2 Macroglobulin

Basic fibroblast growth factor (FGF-2) is important in development, wound healing and angiogenesis. The human plasma proteinase inhibitor α2-macroglobulin (α2M) binds to and regulates the biological activity of various growth factors, including FGF-2. FGF-2 binds specifically and saturably to native α2M and conformationally modified α2M (α2M∗); however, the KD for FGF-2 binding to α2M∗ is 10-fold lower. This study investigates the biochemical nature of the interaction between FGF-2 and α2M∗ and localizes a possible FGF-2 binding site in the α2M subunit. FGF-2 binding to α2M∗ was not affected by shifts in pH between 6.5 and 10; however, increasing temperature decreased the KD for this interaction. The binding affinity of FGF-2 for α2M∗ also increased with increasing ionic strength. These results are consistent with the hypothesis that hydrophobic interactions predominate in promoting FGF-2 association with α2M∗. Consistent with this hypothesis, FGF-2 bound to a glutathione S-transferase fusion protein containing amino acids 591–774 of the α2M subunit (FP3) and to a hydrophobic 16-amino-acid peptide (amino acids 718–733) within FP3. Specific binding of FGF-2 to the 16-amino-acid peptide was inhibited by excess transforming growth factor-β1. When the 16-amino-acid peptide was chemically modified to neutralize the only two charged amino acids, FGF-2-binding activity was unaffected, supporting the predominant role of hydrophobic interactions. FGF-2 presentation to signalling receptors is influenced by growth factor binding to heparan sulphate proteoglycans (HSPGs), which is electrostatic in nature. Our results demonstrate that the interactions of FGF-2 with α2M∗ and HSPGs are biochemically distinct, suggesting that different FGF-2 sequences are involved.

Elucidating the Role of Val-Asn 95 and Arg-Gly 52 Mutations on Structure and Stability of Fibroblast Growth Factor Homologous Factor 2

2019 ◽  
Vol 26 (11) ◽  
pp. 848-859
Author(s):  
Vidyalatha Kolli ◽  
Subhankar Paul ◽  
Praveen Kumar Guttula ◽  
Nandini Sarkar
Keyword(s):  
Amino Acids ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Signal Sequence ◽  
Fibroblast Growth ◽  
Structure And Stability ◽  
Secretion Signal ◽  
Acrylamide Quenching ◽  
Voltage Gated Sodium Channels

Background: Fibroblast growth Factor Homologous Factors (FHFs) belong to a subclass of Fibroblast Growth Factor (FGF) family owing to their high sequence and structural similarities with FGFs. However, despite these similarities, there are properties which set them apart from FGFs. FHFs lack the secretion signal sequence unlike other FGF members, except FGF1 and 2. Unlike FGFs, FHFs are not able to bind to FGF Receptors (FGFRs) and instead have been implicated in binding to Voltage-Gated Sodium Channels (VGSCs), neuronal MAP kinase scaffold protein and islet-brain-2 (IB2). The two amino acids Arg-52 and Val95 are conserved in all FHFs and mutation of these residues lead to its inability to bind with VGSC/IB2. However, it is not clear whether the loss of binding is due to destabilization of the protein on mutation or due to involvement of Arg52 and Val95 in conferring functionality to FHFs. Objective: In the present study, we have mutated these two conserved residues of FHF2 with its corresponding FGF counterpart amino acids and studied the effects of the mutations on the structure and stability of the protein. Methods: Several biophysical methods like isothermal equilibrium denaturation study, ANS fluorescence, intrinsic fluorescence, acrylamide quenching, circular dichroism studies as well as using computational approaches were employed. Results: The single mutations were found to affect the overall stability, conformation and functionality of the protein. Conclusion: Thus, the studies throw light on the role of specific amino acids in deciding the stability, structure and functionality of proteins and will be useful for development of therapeutically engineered proteins.

Isolation and partial molecular characterization of basic fibroblast growth factor from isolated porcine thyroid follicles and entire porcine thyroid glands

1993 ◽  
Vol 129 (5) ◽  
pp. 458-466 ◽  
Author(s):  
Günther Bechtner ◽  
Bernhard Rieder ◽  
Ullrich Linsenmaier ◽  
J Kellermann ◽  
Walter Greil ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Sodium Dodecyl ◽  
Fibroblast Growth ◽  
Thyroid Cells ◽  
Amino Terminal ◽  
Thyroid Glands

Immunoreactive basic fibroblast growth factor (bFGF) could be isolated from the cytosol preparation of isolated porcine thyroid follicles as well as in the conditioned medium from thyroid follicles in suspension culture. A double band with 16 500 and 15 500 D was detected on sodium dodecyl sulfate polyacrylamide gel electrophoresis. In dot blot and western blot the isolated peptide was immunoreactive with a specific anti-bovine bFGF antibody. For further biochemical characterization, bFGF was isolated from entire porcine thyroid glands by ammonium sulfate precipitation, cation exchange chromatography and heparin affinity chromatography. The material obtained from all three origins was identical concerning affinity to heparin and immunoreactivity with the specific anti-bovine bFGF antibody and induced neovascularization in the chorioallantois membranes of chick embryos. Amino acid sequence analysis of the 16-amino-terminal amino acids of the isolated bFGF was in accordance with the established complete 146-amino-acid bFGF molecule except that glycine in position 10 is replaced by phenylalanine. An additionally identified minor peptide presumably is an amino-terminaltruncated form of bFGF, missing the first 15 amino acids. We conclude that the physiological significance of bFGF released by thyroid cells may be the regulation of angiogenesis during thyroid development and goiter growth.

The role of fibroblast growth factor-23 in left atrial volume

2013 ◽  
Vol 165 (5) ◽  
pp. e21 ◽  
Author(s):  
Supawat Ratanapo ◽  
Wonngarm Kittanamongkolchai ◽  
Narat Srivali ◽  
Saeed Ahmed ◽  
Wisit Cheungpasitporn ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Left Atrial ◽  
Fibroblast Growth Factor 23 ◽  
Left Atrial Volume ◽  
Fibroblast Growth ◽  
Atrial Volume
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