scholarly journals Mechanistic Picture for Monomeric Human Fibroblast Growth Factor 1 Stabilization by Heparin Binding

2021 ◽  
Author(s):  
Vivek Govind Kumar ◽  
Shilpi Agrawal ◽  
Thallapuranam Krishnaswamy Suresh Kumar ◽  
Mahmoud Moradi
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Human Fibroblast ◽  
Fibroblast Growth ◽  
Heparin Binding

scholarly journals Mechanistic Picture for Monomeric Human Fibroblast Growth Factor 1 Stabilization by Heparin Binding

2020 ◽  
Author(s):  
Vivek Govind Kumar ◽  
Shilpi Agrawal ◽  
Thallapuranam Krishnaswamy Suresh Kumar ◽  
Mahmoud Moradi
Keyword(s):  
Free Energy ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Conformational Change ◽  
Human Fibroblast ◽  
Md Simulations ◽  
Binding Pocket ◽  
Free Energy Calculations ◽  
Fibroblast Growth ◽  
Heparin Binding

ABSTRACTHuman fibroblast growth factor (FGF) 1 or hFGF1 is a member of the FGF family that is involved in various vital processes such as cell proliferation, cell differentiation, angiogenesis and wound healing. hFGF1, which is associated with low stability in vivo, is known to be stabilized by binding heparin sulfate, a glycosaminoglycan that aids the protein in the activation of its cell surface receptor. The poor thermal and proteolytic stability of hFGF1 and the stabilizing role of heparin have long been observed experimentally; however, the mechanistic details of these phenomena are not well understood. Here, we have used a combination of microsecond-level equilibrium molecular dynamics (MD) simulations, and state-of-the-art enhanced sampling MD simulations to quantitatively characterize the structural dynamics of monomeric hFGF1 in the presence and absence of heparin hexasaccharide. We have observed a conformational change in the heparin-binding pocket of hFGF1 that occurs only in the absence of heparin. Several intramolecular hydrogen bonds were also identified within the heparin-binding pocket, that form only when hFGF1 interacts with heparin. The loss of both intermolecular and intramolecular electrostatic interactions in the absence of heparin plausibly leads to the observed conformational change. This conformational transition results in increased flexibility of the heparin-binding pocket and provides an explanation for the susceptibility of apo hFGF1 to proteolytic degradation and thermal instability. The hFGF1-heparin interaction has also been quantified using absolute binding free energy calculations. Binding affinity (Kd) estimates determined computationally using our novel MD approach are in good quantitative agreement with experimental Kd values from isothermal titration calorimetry experiments. The successful application of a combination of microsecond-level MD and accurate free energy calculations to explain the heparin-mediated stabilization of hFGF1 at a quantitative level, represents a promising approach for studying complex biomolecular interactions between proteins and their binding partners at a detailed molecular level using rigorous physics-based simulation techniques.

Delivery of Human Fibroblast Growth Factor-1 Gene to Brain by Modified Rat Brain Endothelial Cells

2002 ◽  
Vol 67 (4) ◽  
pp. 1643-1652 ◽  
Author(s):  
P. Johnston ◽  
M. Nam ◽  
M. A. Hossain ◽  
R. R. Indurti ◽  
J. L. Mankowski ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Rat Brain ◽  
Fibroblast Growth Factor ◽  
Human Fibroblast ◽  
Fibroblast Growth ◽  
Brain Endothelial Cells ◽  
Rat Brain Endothelial Cells

scholarly journals A New 34-Kilodalton Isoform of Human Fibroblast Growth Factor 2 Is Cap Dependently Synthesized by Using a Non-AUG Start Codon and Behaves as a Survival Factor

1999 ◽  
Vol 19 (1) ◽  
pp. 505-514 ◽  
Author(s):  
Emmanuelle Arnaud ◽  
Christian Touriol ◽  
Christel Boutonnet ◽  
Marie-Claire Gensac ◽  
Stéphan Vagner ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Human Fibroblast ◽  
The Other ◽  
In Vitro Translation ◽  
Start Codon ◽  
Fibroblast Growth Factor 2 ◽  
Initiation Codon ◽  
Fibroblast Growth

ABSTRACT Four isoforms of human fibroblast growth factor 2 (FGF-2) result from alternative initiations of translation at three CUG start codons and one AUG start codon. Here we characterize a new 34-kDa FGF-2 isoform whose expression is initiated at a fifth initiation codon. This 34-kDa FGF-2 was identified in HeLa cells by using an N-terminal directed antibody. Its initiation codon was identified by site-directed mutagenesis as being a CUG codon located at 86 nucleotides (nt) from the FGF-2 mRNA 5′ end. Both in vitro translation and COS-7 cell transfection using bicistronic RNAs demonstrated that the 34-kDa FGF-2 was exclusively expressed in a cap-dependent manner. This contrasted with the expression of the other FGF-2 isoforms of 18, 22, 22.5, and 24 kDa, which is controlled by an internal ribosome entry site (IRES). Strikingly, expression of the other FGF-2 isoforms became partly cap dependent in vitro in the presence of the 5,823-nt-long 3′ untranslated region of FGF-2 mRNA. Thus, the FGF-2 mRNA can be translated both by cap-dependent and IRES-driven mechanisms, the balance between these two mechanisms modulating the ratio of the different FGF-2 isoforms. The function of the new FGF-2 was also investigated. We found that the 34-kDa FGF-2, in contrast to the other isoforms, permitted NIH 3T3 cell survival in low-serum conditions. A new arginine-rich nuclear localization sequence (NLS) in the N-terminal region of the 34-kDa FGF-2 was characterized and found to be similar to the NLS of human immunodeficiency virus type 1 Rev protein. These data suggest that the function of the 34-kDa FGF-2 is mediated by nuclear targets.

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