The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform
Erkki Ruoslahti - One of the best experts on this subject based on the ideXlab platform.
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isolation of a highly specific ligand for the alpha 5 beta 1 integrin from a phage display library
Journal of Cell Biology, 1994Co-Authors: Erkki Koivunen, Bingcheng Wang, Erkki RuoslahtiAbstract:Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage Sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR Sequence Occurs in the cell-binding region of the fibronectin molecule, this Sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a Sequence RRETAWA that does not bear obvious resemblance to known integrin ligand Sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.
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Isolation of a highly specific ligand for the α5β1 integrin from a phage display library
Journal of Cell Biology, 1994Co-Authors: Erkki Koivunen, Bingcheng Wang, Erkki RuoslahtiAbstract:Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage Sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR Sequence Occurs in the cell-binding region of the fibronectin molecule, this Sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a Sequence RRETAWA that does not bear obvious resemblance to known integrin ligand Sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.
Erkki Koivunen - One of the best experts on this subject based on the ideXlab platform.
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isolation of a highly specific ligand for the alpha 5 beta 1 integrin from a phage display library
Journal of Cell Biology, 1994Co-Authors: Erkki Koivunen, Bingcheng Wang, Erkki RuoslahtiAbstract:Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage Sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR Sequence Occurs in the cell-binding region of the fibronectin molecule, this Sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a Sequence RRETAWA that does not bear obvious resemblance to known integrin ligand Sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.
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Isolation of a highly specific ligand for the α5β1 integrin from a phage display library
Journal of Cell Biology, 1994Co-Authors: Erkki Koivunen, Bingcheng Wang, Erkki RuoslahtiAbstract:Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage Sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR Sequence Occurs in the cell-binding region of the fibronectin molecule, this Sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a Sequence RRETAWA that does not bear obvious resemblance to known integrin ligand Sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.
Bingcheng Wang - One of the best experts on this subject based on the ideXlab platform.
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isolation of a highly specific ligand for the alpha 5 beta 1 integrin from a phage display library
Journal of Cell Biology, 1994Co-Authors: Erkki Koivunen, Bingcheng Wang, Erkki RuoslahtiAbstract:Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage Sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR Sequence Occurs in the cell-binding region of the fibronectin molecule, this Sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a Sequence RRETAWA that does not bear obvious resemblance to known integrin ligand Sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.
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Isolation of a highly specific ligand for the α5β1 integrin from a phage display library
Journal of Cell Biology, 1994Co-Authors: Erkki Koivunen, Bingcheng Wang, Erkki RuoslahtiAbstract:Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage Sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR Sequence Occurs in the cell-binding region of the fibronectin molecule, this Sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a Sequence RRETAWA that does not bear obvious resemblance to known integrin ligand Sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.
G Mahon - One of the best experts on this subject based on the ideXlab platform.
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cpg island methylation in pten mgmt and e h cadherin promoters mutations of k ras and b raf may indicate how progression in the colorectal adenocarcinoma Sequence Occurs
Journal of Clinical Oncology, 2011Co-Authors: B Metzger, M Dicato, G MahonAbstract:3608 Background: The colorectal adenocarcinoma Sequence summarizes the epigenetic and genetic modifications, which arise during cancer progression. These modifications have effect on the methylation status of different gene promoters and mutations in the K-ras and B-raf genes. Included in the Sequence during cancer progression may be, as we have previously shown (ESMO 2010, abstr.:646P): methylation of the gene promoters of H-cadherin then of MGMT deregulating removal toxic methyl adducts on guanine bases and inducing the activation of K-ras through G to A point mutations, activation of B-raf gene by a V600E mutation and finally methylation of E-cadherin, linked to emergence of metastasis. Methods: DNA extraction was obtained by standard methods from resected tumour samples. In order to add PTEN methylation status in this Sequence, shown to co-occur with K-ras and B-raf mutations in colorectal cancer (CRC), we screened for PTEN inactivation by promoter hypermethylation over 200 CRC patients from which MGM...
G J De Lange - One of the best experts on this subject based on the ideXlab platform.
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elemental and major biochemical changes across an oxidation front in a relict turbidite an oxygen effect
Geochimica et Cosmochimica Acta, 1995Co-Authors: Gregory L Cowie, John I Hedges, Fredrick G Prahl, G J De LangeAbstract:Abstract The elemental and major biochemical compositions of the relict f-turbidite sampled in two cores from the Madeira Abyssal Plain were determined. This fine-grained, distal Sequence Occurs at ca. 9 m core depth and includes a surficial oxidized horizon defined by a distinct color change. Oxygen diffused downward through sediments above this interface and in ca. 10 kyr destroyed 80% of the organic substances that below the front had survived degradation in the presence of porewater sulfate for ca. 140 kyr. These deposits provide an opportunity to establish the extent and selectivity of oxic sedimentary degradation under natural conditions without the usual complications of bioturbation and varying sources or sedimentation rates. In both cores, a sample from the upper oxidized layer was compared to two samples from the underlying unoxidized layers. The unoxidized Sequences of both turbidities contained 0.93–1.02 wt% organic carbon (OC) and 0.10–0.11 wt% total nitrogen (TN). Approximately 20% of the initial OC and 40% of the initial TN remained in the oxidized horizons, with a consequent decrease in atomic C/N ratio from ca. 11 to ca. 5. All samples gave very low yields of lignin phenols and comparable OC-normalized yields of total aldoses and amino acids, and indicated predominantly marine organic matter (OM) and nonselective oxic degradation of these biochemical classes. Compositions of individual aldoses and amino acids generally were also similar in surface and deep sediments, except that the oxidized horizons yielded markedly elevated (3–5X) percentages of nonprotein amino acids. This study clearly demonstrates that prolonged exposure to OZ can lead to organic matter alteration which is far more extensive than that obtained with sulfate alone. In comparison to early diagenesis, however, alteration of the measured biochemicals was largely nonselective. Such oxidation reactions could control the distribution and composition of organic matter in slowly accumulating continental rise and deep-ocean environments.
