The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

Tetsuo Asakura - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis and characterization of cell-Adhesive silk-like proteins constructed from the sequences of Anaphe silk fibroin and fibronectin.
    Biomacromolecules, 2009
    Co-Authors: Chikako Tanaka, Tetsuo Asakura
    Abstract:

    New silk-like recombinant proteins, [(AAG)(6)ASTGRGDSPAAS](n) and [(AG)(9)ASTGRGDSPAAS](n), with high cell Adhesive activities were designed and produced from E. coli. These are recombinant proteins with characteristic sequences from the silk fibroin of a wild silkworm, Anaphe , and the cell Adhesive Region, including the sequence RGD derived from fibronectin. They showed higher cell adhesion activity than the parent protein, Anaphe silk fibroin without the RGD sequence. In addition, the activities were very similar to that of collagen, which acted as a positive control. Thus, it is demonstrated that the primary structure of Anaphe silk fibroin, which is composed largely of alanine and glycine residues, can be used as a platform for the basic structures of silk-like cell Adhesive proteins. The structural characterization of the silk-like recombinant proteins was performed with (13)C CP/MAS NMR.

  • Production and characterization of a silk-like hybrid protein, based on the polyalanine Region of Samia cynthia ricini silk fibroin and a cell Adhesive Region derived from fibronectin
    Biomaterials, 2004
    Co-Authors: Tetsuo Asakura, Chikako Tanaka, Mingying Yang, Juming Yao, Masato Kurokawa
    Abstract:

    Abstract There are a variety of silkworms and silk fibroins produced by them. Silks have many inherent suitable properties for biomaterials. In this paper, a novel silk-like hybrid protein, [DGG(A) 12 GGAASTGRGDSPAAS] 5 , which consists of polyalanine Region of silk fibroin from a wild silkworm, Samia cynthia ricini , and cell Adhesive Region including Arg-Gly-Asp (RGD) sequence, derived from fibronectin, was designed and produced. The genes encoding the hybrid protein were constructed and expressed in Escherichia coli . The main conformation of the polyalanine Region, that is, either α -helix or β -sheet, could be easily controlled by treatment with different acidic solvents, trifluoroacetic acid or formic acid, respectively. This structural change was monitored with 13 C CP/MAS NMR. Higher cell Adhesive and growth activities of the hybrid protein compared with those of collagen were obtained.

Chikako Tanaka - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis and characterization of cell-Adhesive silk-like proteins constructed from the sequences of Anaphe silk fibroin and fibronectin.
    Biomacromolecules, 2009
    Co-Authors: Chikako Tanaka, Tetsuo Asakura
    Abstract:

    New silk-like recombinant proteins, [(AAG)(6)ASTGRGDSPAAS](n) and [(AG)(9)ASTGRGDSPAAS](n), with high cell Adhesive activities were designed and produced from E. coli. These are recombinant proteins with characteristic sequences from the silk fibroin of a wild silkworm, Anaphe , and the cell Adhesive Region, including the sequence RGD derived from fibronectin. They showed higher cell adhesion activity than the parent protein, Anaphe silk fibroin without the RGD sequence. In addition, the activities were very similar to that of collagen, which acted as a positive control. Thus, it is demonstrated that the primary structure of Anaphe silk fibroin, which is composed largely of alanine and glycine residues, can be used as a platform for the basic structures of silk-like cell Adhesive proteins. The structural characterization of the silk-like recombinant proteins was performed with (13)C CP/MAS NMR.

  • Production and characterization of a silk-like hybrid protein, based on the polyalanine Region of Samia cynthia ricini silk fibroin and a cell Adhesive Region derived from fibronectin
    Biomaterials, 2004
    Co-Authors: Tetsuo Asakura, Chikako Tanaka, Mingying Yang, Juming Yao, Masato Kurokawa
    Abstract:

    Abstract There are a variety of silkworms and silk fibroins produced by them. Silks have many inherent suitable properties for biomaterials. In this paper, a novel silk-like hybrid protein, [DGG(A) 12 GGAASTGRGDSPAAS] 5 , which consists of polyalanine Region of silk fibroin from a wild silkworm, Samia cynthia ricini , and cell Adhesive Region including Arg-Gly-Asp (RGD) sequence, derived from fibronectin, was designed and produced. The genes encoding the hybrid protein were constructed and expressed in Escherichia coli . The main conformation of the polyalanine Region, that is, either α -helix or β -sheet, could be easily controlled by treatment with different acidic solvents, trifluoroacetic acid or formic acid, respectively. This structural change was monitored with 13 C CP/MAS NMR. Higher cell Adhesive and growth activities of the hybrid protein compared with those of collagen were obtained.

Amitava Chatterjee - One of the best experts on this subject based on the ideXlab platform.

  • Rapid expression and activation of MMP-2 and MMP-9 upon exposure of human breast cancer cells (MCF-7) to fibronectin in serum free medium
    Life Sciences, 2007
    Co-Authors: Shamik Das, Aniruddha Banerji, Eva Frei, Amitava Chatterjee
    Abstract:

    Abstract Interactions between tumour cells and the extracellular matrix (ECM) strongly influence tumour development, affecting cell survival, proliferation and migration. Many of these interactions are mediated through a family of cell surface receptors named integrins. Fibronectin and its integrin receptors play important roles in tumour development. The α5β1 integrin interacts with the central cell Adhesive Region of fibronectin and requires both the RGD and synergy sites for maximal binding. Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases. They are capable of digesting the different components of the ECM and basement membrane. The ECM gives structural support to cells and plays a central role in cell adhesion, differentiation, proliferation and migration. Binding of ECM to integrins modulates expression and activity of the different MMPs. Our experimental findings demonstrate that cultivation of human breast cancer cells, MCF-7, in serum free medium in the presence of fibronectin upregulates the activity of MMP-2 and MMP-9. Blocking of α5β1 integrin with anti-α5 monoclonal antibody inhibits the fibronectin-induced MMP activation response appreciably. This strongly indicates α5β1 mediated signalling events in activation of MMP-2 and MMP-9. Phosphorylation of FAK and PI-3 kinase and the nuclear translocation of ERK and NF-κB upon fibronectin binding demonstrate possible participation of the FAK/PI-3K/ERK signalling pathways in the regulation of MMP-2 activity.

  • Rapid expression and activation of MMP-2 and MMP-9 upon exposure of human breast cancer cells (MCF-7) to fibronectin in serum free medium.
    Life sciences, 2007
    Co-Authors: Shamik Das, Aniruddha Banerji, Eva Frei, Amitava Chatterjee
    Abstract:

    Interactions between tumour cells and the extracellular matrix (ECM) strongly influence tumour development, affecting cell survival, proliferation and migration. Many of these interactions are mediated through a family of cell surface receptors named integrins. Fibronectin and its integrin receptors play important roles in tumour development. The alpha5beta 1 integrin interacts with the central cell Adhesive Region of fibronectin and requires both the RGD and synergy sites for maximal binding. Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases. They are capable of digesting the different components of the ECM and basement membrane. The ECM gives structural support to cells and plays a central role in cell adhesion, differentiation, proliferation and migration. Binding of ECM to integrins modulates expression and activity of the different MMPs. Our experimental findings demonstrate that cultivation of human breast cancer cells, MCF-7, in serum free medium in the presence of fibronectin upregulates the activity of MMP-2 and MMP-9. Blocking of alpha5beta 1 integrin with anti-alpha5 monoclonal antibody inhibits the fibronectin-induced MMP activation response appreciably. This strongly indicates alpha5beta 1 mediated signalling events in activation of MMP-2 and MMP-9. Phosphorylation of FAK and PI-3 kinase and the nuclear translocation of ERK and NF-kappaB upon fibronectin binding demonstrate possible participation of the FAK/PI-3K/ERK signalling pathways in the regulation of MMP-2 activity.

Masato Kurokawa - One of the best experts on this subject based on the ideXlab platform.

Shamik Das - One of the best experts on this subject based on the ideXlab platform.

  • Rapid expression and activation of MMP-2 and MMP-9 upon exposure of human breast cancer cells (MCF-7) to fibronectin in serum free medium
    Life Sciences, 2007
    Co-Authors: Shamik Das, Aniruddha Banerji, Eva Frei, Amitava Chatterjee
    Abstract:

    Abstract Interactions between tumour cells and the extracellular matrix (ECM) strongly influence tumour development, affecting cell survival, proliferation and migration. Many of these interactions are mediated through a family of cell surface receptors named integrins. Fibronectin and its integrin receptors play important roles in tumour development. The α5β1 integrin interacts with the central cell Adhesive Region of fibronectin and requires both the RGD and synergy sites for maximal binding. Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases. They are capable of digesting the different components of the ECM and basement membrane. The ECM gives structural support to cells and plays a central role in cell adhesion, differentiation, proliferation and migration. Binding of ECM to integrins modulates expression and activity of the different MMPs. Our experimental findings demonstrate that cultivation of human breast cancer cells, MCF-7, in serum free medium in the presence of fibronectin upregulates the activity of MMP-2 and MMP-9. Blocking of α5β1 integrin with anti-α5 monoclonal antibody inhibits the fibronectin-induced MMP activation response appreciably. This strongly indicates α5β1 mediated signalling events in activation of MMP-2 and MMP-9. Phosphorylation of FAK and PI-3 kinase and the nuclear translocation of ERK and NF-κB upon fibronectin binding demonstrate possible participation of the FAK/PI-3K/ERK signalling pathways in the regulation of MMP-2 activity.

  • Rapid expression and activation of MMP-2 and MMP-9 upon exposure of human breast cancer cells (MCF-7) to fibronectin in serum free medium.
    Life sciences, 2007
    Co-Authors: Shamik Das, Aniruddha Banerji, Eva Frei, Amitava Chatterjee
    Abstract:

    Interactions between tumour cells and the extracellular matrix (ECM) strongly influence tumour development, affecting cell survival, proliferation and migration. Many of these interactions are mediated through a family of cell surface receptors named integrins. Fibronectin and its integrin receptors play important roles in tumour development. The alpha5beta 1 integrin interacts with the central cell Adhesive Region of fibronectin and requires both the RGD and synergy sites for maximal binding. Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases. They are capable of digesting the different components of the ECM and basement membrane. The ECM gives structural support to cells and plays a central role in cell adhesion, differentiation, proliferation and migration. Binding of ECM to integrins modulates expression and activity of the different MMPs. Our experimental findings demonstrate that cultivation of human breast cancer cells, MCF-7, in serum free medium in the presence of fibronectin upregulates the activity of MMP-2 and MMP-9. Blocking of alpha5beta 1 integrin with anti-alpha5 monoclonal antibody inhibits the fibronectin-induced MMP activation response appreciably. This strongly indicates alpha5beta 1 mediated signalling events in activation of MMP-2 and MMP-9. Phosphorylation of FAK and PI-3 kinase and the nuclear translocation of ERK and NF-kappaB upon fibronectin binding demonstrate possible participation of the FAK/PI-3K/ERK signalling pathways in the regulation of MMP-2 activity.