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Research has been conducted on the all-beta protein acidic fibroblast growth factor and the peptides involved in the receptor binding. The helical propensity of the growth factor and the peptides has been investigated via the use of the circular dichroism and proton nuclear magnetic resonance.

Research has been conducted on the insulin-like growth factor-binding proteins. Results include molecular characterization of circulating human IGFBP-4 fragments that have been formed in vivo.

Research has been conducted on the acidic fibroblast growth factor (aFGF). The vasodilatory activity of the aFGF has been investigated.

Acidic and basic fibroblast growth factors (FGFs) share a wide range of diverse biological activities. To date, low levels of FGF have not been correlated with a pathophysiologic state. We report that blood vessels of spontaneously hypertensive rats are shown to be associated with a marked decrement in endothelial basic FGF content. This decrement correlates both with hypertension and with a decrease in the endothelial content of nitric oxide synthase. Restoration of FGF to physiological levels in the vascular wall, either by systemic administration or by in vivo gene transfer, significantly augmented the number of endothelial cells with positive immunostaining for nitric oxide synthase, corrected hypertension, and ameliorated endothelial-dependent responses to vasoconstrictors. These results suggest an important role for FGFs in blood pressure homeostasis and open new avenues for the understanding of the etiology and treatment of hypertension.

Acidic and basic fibroblast growth factors (FGFs) are members of a family of proteins that are broad-spectrum mitogens, have diverse hormone-like activities, and function in tumorigenesis. FGF's ability to raise the concentration of intracellular calcium ion suggests that FGF could induce the synthesis of endothelium-derived relaxing factor (EDRF) and consequently vasodilation. Systemic administration of FGF decreased arterial blood pressure. This effect was mediated by EDRF and by adenosine triphosphate--sensitive potassium ion channels. The hypotensive effect of FGF was segregated from its mitogenic activity by protein engineering. These results extend the range of FGF autocrine activities and potential therapeutic applications, emphasize the role of endothelium as an arterial blood pressure--regulating organ, and provide insight on the structural basis of FGF functions., THE PROTEINS OF THE FGF FAMILY are broad spectrum mitogens synthesized in vertebrates in tissues derived from mesoderm and neuroectoderm [1]. However, basic FGF (bFGF) also has non-mitogenic activities [2, [...]

A study is conducted which describes the biological, structural, and conformational details of the binding of glycosylaminoglycans (GAGs) to polypeptides of the fibroblast growth factor (FGF) family, the chemokines, and to antithrombin-III (AT-III). The results obtained indicate that within the complex with FGF-1, the iduronate rings of the bound oligosaccharide display a conformational equilibrium between the (super 1)C(sub 4) and (super 2)S(sub 0) forms.

Research describes the three-dimensional solution structure of recombinant RicC3 albumin protein from the castor beans. The core structure display a RMSD radius of 0.64 Angstroms. The nuclear magnetic resonance structure shows five amphipatic helices in a right-handed super helix, unique to this lipid transfer protein. r

Brain-Derived Acidic Fibroblast Growth Factor: Complete Amino Acid Sequence and Homologies Brain has been recognized as a plentiful source of mitogenic activity for primary fibroblasts for almost 50 years (1). [...]

Acid denaturation of acidic fibroblast growth factor (aFGF) at low ionic strength was monitored by far-ultraviolet circular dichroism and intrinsic fluorescence. The two spectroscopic probes displayed noncoincident transitions, which suggested the accumulation of pauly folded species around pH 4.0. Although under these conditions the fluorescence of aFGF resembled that of the unfolded form of the protein, farultraviolet circular dichroism and proton nuclear magnetic resonance spectra indicated the presence of persistent secondary and tertiary structure. Moreover, at pH 4.0, aFGF showed cooperative thermal denaturation and interacted weakly with the hydrophobic probe N-phenyl-1-naphthylamine, showing a relatively high level of structure that did not fit into the classical molten globule category. This intermediate is also capable of interacting with liposomes and might represent a membrane translocation-competent form. [ABSTRACT FROM AUTHOR]

The role of rhodoquinone and ubiquinone in the oxygen photoreducing (photooxidase) activity of Rhodospirillum rubrum was investigated. The sole addition of purified rhodoquinone restored photooxidase activity in isolated chromatophores which had been extracted with organic solvents and which were apparently free of secondary acceptor ubiquinone. Rhodoquinone also enhanced photooxidase activity in photoreaction center preparations from which secondary ubiquinone seemed to have been removed. Those results suggest that rhodoquinone accepts electrons directly from primary ubiquinone during chromatophore photooxidase activity. In contrast, rhodoquinone does not participate in the basal activity of photoreaction center preparations, which seems to result from the autooxidation of both primary and secondary ubiquinone. [ABSTRACT FROM AUTHOR]

Biosynthesis of heparan sulfate (HS) is strictly regulated to yield products with cell/tissue-specific composition. Interactions between HS and a variety of proteins, including growth factors and morphogens, are essential for embryonic development and for homeostasis in the adult. Fibroblast growth factors (FGFs) and their various receptors (FRs) form ternary complexes with HS, as required for receptor signaling. Libraries of HS-related, radiolabeled oligosaccharides were generated by chemo-enzymatic modification of heparin and tested for affinity to immobilized FR ectodomains in the presence of FGF1 or FGF2. Experiments were designed to enable assessment of N-sulfated 8- and 10-mers with defined numbers of iduronic acid 2-O-sulfate and glucosamine 6-O-sulfate groups. FGF1 and FGF2 were found to require similar oligosaccharides in complex formation with FR1c-3c, FGF2 affording somewhat more efficient oligosaccharide recruitment than FGF1. FR4, contrary to FR1c-3c, bound oligosaccharides at physiological ionic conditions even in the absence of FGFs, and this interaction was further promoted by FGF1 but not by FGF2. In all systems studied, the stability of FGF-oligosaccharide-FR complexes correlated with the overall level of saccharide O-sulfation rather than on the precise distribution of sulfate groups. [ABSTRACT FROM AUTHOR]

The article examines the conformational flexibility of a synthetic glycosylaminoglycan (GAGs) bound to a fibroblast growth factor (FGF). The study of the molecular recognition of carbohydrates by protein receptors at atomic level has attracted considerable interest during the past few years, due to their key role in a variety of relevant physiological processes. In particular, major attention has been paid to the study of the biological, structural, and conformational details of the binding of GAGs to polypeptides of the FGF family.