Cell-physiological effects of elastin derived(VGVAPG)n oligomers in a unicellular model system (original) (raw)
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The Journal of Cell Biology, 1984
Recent studies have demonstrated that tropoelastin and elastin-derived peptides are chemotactic for fibroblasts and monocytes. To identify the chemotactic sites on elastin, we examined the chemotactic activity of VaI-Gly-VaI-Ala-Pro-Gly (VGVAPG), a repeating peptide in tropoelastin. We observed that VGVAPG was chemotactic for fibroblasts and monocytes, with optimal activity at ~10 -8 M, and that the chemotactic activity of VGVAPG was substantial (half or greater) relative to the maximum responses to other chemotactic factors such as platelet-derived growth factor for fibroblasts and formyl-methionyl-leucylphenylalanine for monocytes. The possibility that at least part of the chemotactic activity in tropoelastin and elastin peptides is contained in VGVAPG sequences was supported by the following: (a) polyclonal antibody to bovine elastin selectively blocked the fibroblast and monocyte chemotactic activity of both elastin-derived peptides and VGVAPG; (b) monocyte chemotaxis to VGVAPG was selectively blocked by preexposing the cells to elastin peptides; and (c) undifferentiated (nonelastin producing) bovine ligament fibroblasts, capable of chemotaxis to platelet-derived growth factor, did not show chemotactic responsiveness to either VGVAPG or elastin peptides until after matrix-induced differentiation and the onset of elastin synthesis. These studies suggest that small synthetic peptides may be able to reproduce the chemotactic activity associated with elastin-derived peptides and tropoelastin.
Structure-activity relationships for some elastin-derived peptide chemoattractants
The Journal of Peptide Research, 2009
In an attempt to explore the relationships between conformation of chemotactic peptides related to elastin and their biological activity we have studied five peptides: VGVAPG, VGVPG, VGAPG, GVAPG and GGVPG in solvents of different polarities which may mimic the environmental conditions at the receptor site. CD and NMR studies showed that GVAPG has no preference for structured conformations, while the other peptides may assume folded conformations in organic solvents. All these peptides but GGVPG showed chemotactic activity for monocytes. The chemotactic activity of VGVPG, VGAPG and VGVAPG was inhibited by lactose, while chemotaxis of peptide GVAPG was insensitive to lactose, suggesting the existence of different chemotactic receptors. t 3 Munksgaard 1997.
Identification of a tumor cell receptor for VGVAPG, an elastin-derived chemotactic peptide
The Journal of Cell Biology, 1988
Extracellular matrix proteins and their proteolytic products have been shown to modulate cell motility. We have found that certain tumor cells display a chemotactic response to degradation products of the matrix protein elastin, and to an elastin-derived peptide, VGVAPG. The hexapeptide VGVAPG is a particularly potent chemotaxin for lung-colonizing Lewis lung carcinoma cells (line M27), with 5 nM VGVAPG eliciting maximal chemotactic response when assayed in 48-microwell chemotaxis chambers. Binding of the elastin-derived peptide to M27 cells was studied using a tyrosinated analog (Y-VGVAPG) to allow iodination. Scatchard analysis of [125I]Y-VGVAPG binding to viable M27 tumor cells at both 37 and 4 degrees C indicates the presence of a single class of high affinity binding sites. The dissociation constant obtained from these studies (2.7 X 10(-9) M) is equivalent to the concentration of VGVAPG required for chemotactic activity. The receptor molecule was identified as an Mr 59,000 spe...
Chemotaxis of fibroblasts toward nonapeptide of elastin
Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, 1988
Bovine ligamentum fibroblasts, which produce elastin, migrate towards a positive chemical gradient of human platelet-derived growth factor and of the tropoelastin repeat hexapeptide Val-Gly-VaI-Ala-Pro-Gly, as previously shown. They are also responsive to two permutations of a nonapeptide that repeats in tropoelastin, i.e., Ala-Gly-Val-Pro-Gly-Phe-Gly-Vai-Gly and Gly-Phe-Giy-Val-Gly-Ala-Gly-Val-Pro. Concentration curves and checkerboard assays prove that the nonapeptides are chemoattractants. The component pentapeptide, Gly-Phe-Gly-Val-Gly, is chemotactic, while the component tetrapeptide Ala-Gly-VaI-Pro is not. The hexapeptide competitively suppresses the nonapeptide chemotaxis suggesting the involvement of a common cell receptor. The results support the concept that elastin has multiple cell recognition sites as measured by the chemotactic response and that among the hydrophobic repeating sequences of elastin chemotacticity is selectively and multiply localized.
Elastin repeat peptides as chemoattractants for bovine aortic endothelial cells
Journal of Cellular Physiology, 1989
Cultured bovine aortic endothelial cells migrate toward a concentration gradient of repeating elastin peptides, specifically the repeating nonamers Gly-Phe-Gly-Val-Cly-Ala-Gly-Val-Pro and Gly-Leu-Cly-Val-Gly-Ala-Gly-Val-Pro and the repeating hexamer Val-Cly-Val-Ala-Pro-Gly. Dose-response experiments demonstrate that the peak of activity occurs at 8 x 1 OP8 M for the nonapeptides and 1 x 1 0-8 M for the hexapeptide. Checkerboard assays establish that the movement is chernotaxis and not chemokinesis. Because of the concentration difference in the responsiveness between the nonapeptide and the hexapeptide, the cells can differentiate between the two types of repeats. The positive control for the chernotaxis studies was fibronectin.
Susceptibility of Baboon Aorta Elastin to Proteolysis
Biological chemistry Hoppe-Seyler, 1990
Elastin was purified from baboon aorta using Achromobacter collagenase and its susceptibility to proteolysis by various enzymes was studied. Human leukocyte elastase (HLE) hydrolysed baboon aortic elastin 8 times faster than human cathepsin G. Bovine chymotrypsin had virtually no activity against this substrate. The kinetic constants Fand [S 50 ] of aortic elastin hydrolysis by HLE (0.15) were 0.00286 mg x 1 x min" 1 and 0.158 mg x m/' 1 , respectively. One mg of this elastin could be saturated with 5.6 ^g of HLE. As with elastins isolated from other sources, the hydrolysis of baboon aortic elastin by HLE was highly sensitive to ionic strength, and a biphasic effect was obtained with increasing NaCl concentrations. A nearly 2-fold stimulation of elastolysis was observed at a 0.15M NaCl concentration. Further increase in ionic strength led to a continuous decrease of the rate of elastolysis which paralleled the decrease of adsorption of elastase to baboon aortic elastin. Cathepsin G, but not bovine-chymotrypsin, was able to stimulate the rate of hydrolysis of baboon aortic elastin by HLE. A 1.7 fold stimulation was observed for a 1:1 molar ratio of the two proteinases and rose to 2.1 for a HLE/Cat. G ratio equal to 8. Empfindlichkeit von Pavianaorten-E lastin gegenüber Proteinasen Zusammenfassung: Elastin wurde mit Hilfe von Achromobacter-Kollagenase aus Pavianaorten gereinigt und seine Empfindlichkeit gegenüber verschiedenen Proteinasen untersucht. Elastase aus menschlichen Leukozyten (HLE) hydrolysierte das Elastin 8mal schneller als menschliches Cathepsin G; Rinder-Chymotrypsin war völlig unwirksam. Die kinetischen Konstanten der Elastin-Hydrolyse mit HLE (0.15) waren V= 0.00286 mg x m/' 1 x min' 1 und [S 50 ] = 0.158 mg x m/" 1. 5.6 ^g HLE sättigten l mg Elastin. Ähnlich wie bei aus anderen Organen isolierten Elastinen ist die Hydrolysegeschwindigkeit des Pavianaorten-Elastins von der lonenstärke stark abhängig, wobei dieser Effekt biphasisch ist. Die Elastolyse ist bei 0.15M NaCl fast auf das Doppelte beschleunigt. Weitere Erhöhung der lonenstärke führt zu einer Verminderung der Adsorption der Elastase an das Substrat und zu einer Abnahme der Geschwindigkeit der Elastolyse. Cathepsin G, nicht aber Rinder-a-Chymotrypsin, stimuliert die Hydrolyse des Elastins durch HLE. Im molekularen Verhältnis l: l angewandt, stimuliert Cathepsin G l.Tfach, und im Verhältnis 8:1 2.1fach die Wirkung der HLE.
Effect of elastin peptides on ion fluxes in mononuclear cells, fibroblasts, and smooth muscle cells
Proceedings of the National Academy of Sciences, 1987
Elastin peptides prepared by alcoholic potassium hydroxide degradation of highly purified fibrous elastin from bovine ligamentum nuchae (c-elastin) were shown to act on the ion channels of human monocytes, aorta smooth muscle cells, and skin fibroblasts. In small amounts (between 0.1 and 1 ,ug/ml), elastin peptides strongly increased calcium influx and inhibited calcium efflux by an apparently calmodulindependent mechanism. They also were shown to increase sodium influx and to decrease rubidium influx in monocyte preparations obtained from human blood. Only the ouabainsensitive portion of rubidium influx was inhibited. The action of elastin peptides is strongly concentration-dependent; the maximal activity observed in the above reactions was <1 /.g/ml. These results suggest that elastin peptides may play a role in the regulation of the biological activity of mesenchymal cells, in the proximity of which they are released by the action of elastase-type enzymes. Such enzymes were demonstrated in aorta smooth muscle cells (membrane-bound serine protease) and in fibroblasts (metalloprotease). Monocytes and polymorphonuclear leukocytes were also shown to carry elastase-type enzymes. The release of peptides from elastin by elastase-type enzymes and the action of such peptides on the ion fluxes through the cell membrane may well be involved in mechanisms of the modulation ofthe phenotype ofmesenchymal cells during aging as well as in the development of age-dependent pathologies such as arterioclerosis.
Identification of elastin peptides with vasorelaxant activity on rat thoracic aorta
The International Journal of Biochemistry & Cell Biology, 1998
Elastin peptides obtained in vivo from the enzymatic degradation of elastic ®bers are present in the circulating human blood. In order to verify the role that these peptides may have in the regulation of the vascular tone, the activity of several peptides identi®ed in the elastolytic digest of human elastin and some of their structural homologues has been tested. Three of these peptides show a vasorelaxant activity in isolated rat aorta precontracted by phenylephrine. The activity observed is higher in the absence of the endothelium; in these conditions the IC 50 for the peptides Val±Gly±Val±Ala±Pro±Gly, Val±Gly±Val±Pro±Gly and Val±Gly±Val±Hyp±Gly was 40 2 2, 732 2 and 10 2 1 ng/ml, respectively. They are active in the range of the pathological circulating concentration and their role could be important in the regulation of vascular tone during several elastin degradative diseases.
Elastin binds to a multifunctional 67-kilodalton peripheral membrane protein
Biochemistry, 1989
Elastin binding proteins from plasma membranes of elastin-producing cells were isolated by affinity chromatography on immobilized elastin peptides. Three proteins of 67,61, and 55 kDa were released from the elastin resin by guanidine/detergent, soluble elastin peptides, synthetic peptide VGVAPG, or galactoside sugars, but not by synthetic RGD-containing peptide or sugars not related to galactose. All three proteins incorporated radiolabel upon extracellular iodination and contained [3H]leucine following metabolic labeling, confirming that each is a synthetic product of the cell. The 67-kDa protein could be released from the cell surface with lactose-containing buffers, whereas solubilization of the 6 1and 55-kDa components required the presence of detergent. Although all three proteins were retained on elastin affinity columns, the 61-and 55-kDa components were retained only in the presence of 67-kDa protein, suggesting that the 67-kDa protein binds elastin and the 61-and 55-kDa proteins bind to the 67-kDa protein. We propose that the 67-, 61-, and 55-kDa proteins constitute an elastin-receptor complex that forms a transmembrane link between the extracellular matrix and the intracellular compartment.