Tissue (type II) transglutaminase covalently incorporates itself, fibrinogen, or fibronectin into high molecular weight complexes on the extracellular surface of isolated hepatocytes. Use of 2-[(2-oxopropyl)thio] imidazolium derivatives as cellular transglutaminase inactivators
| Autor: | Jose Martinez, A M Stern, Carl Barsigian |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Macromolecular Substances
Tissue transglutaminase Blotting Western Biochemistry Putrescine medicine Animals Binding site Molecular Biology Polyacrylamide gel electrophoresis Cells Cultured Antiserum Transglutaminases biology Molecular mass Immune Sera Cell Membrane Imidazoles Fibrinogen Cell Biology Factor XIII Molecular biology Fibronectins Isoenzymes Fibronectin medicine.anatomical_structure Liver Hepatocyte biology.protein Electrophoresis Polyacrylamide Gel Rabbits Protein Binding medicine.drug |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0021-9258 |
| DOI: | 10.1016/s0021-9258(18)54600-7 |
| Popis: | Rabbit hepatocyte surface-expressed tissue (type II) transglutaminase is shown to act as a binding site for fibrinogen or fibronectin and to covalently incorporate these glycoproteins, in addition to itself, into extracellular high molecular weight complexes. This concept is supported by the observation that a nonpeptidyl, active site-directed transglutaminase inactivator (L683685) elicited concentration-dependent (0.1-10 microM) decreases in the calcium-dependent binding and covalent cross-linking of 125I-fibrinogen, 125I-fibronectin, or [14C]putrescine by hepatocyte suspensions. In corroboration with these findings, an antiserum against rabbit liver transglutaminase, which did not cross-react with rabbit factor XIII, elicited concentration-dependent decreases in the calcium-dependent binding and covalent cross-linking of 125I-fibrinogen or [14C]putrescine by hepatocyte suspensions. Western blots of sodium dodecyl sulfate/Triton-insoluble hepatocyte fractions conducted with this antiserum, with a polyclonal antiserum against human erythrocyte transglutaminase, or with a monoclonal antibody (CUB-7401) against guinea pig liver transglutaminase detected the 80-kDa tissue transglutaminase, as well as tissue transglutaminase-immunoreactive bands of higher molecular mass (range of 90 to greater than 200 kDa). The higher molecular weight species were preferentially incorporated, in a time- and calcium-dependent manner, into very high molecular weight complexes which did not enter the stacking gel. Incorporation of these tissue transglutaminase-containing bands into the high molecular weight complexes was inhibited by L683685, indicating that cross-linking by the enzyme was responsible for the assembly of the complexes of which tissue transglutaminase was itself a component. Cellular integrins did not mediate ligand binding under the experimental conditions, as evidenced by the failure of the Arg-Gly-Asp-Ser tetrapeptide or anti-integrin antibodies to inhibit binding or cross-linking of 125I-fibrinogen or 125I-fibronectin, in the presence or absence of transglutaminase inactivators. |
| Databáze: | OpenAIRE |
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