The Fibronectin-binding Domain of Transglutaminase (∗)

• Published in: The Journal of biological chemistry Vol. 270; no. 10; pp. 5654 - 5658
• Main Authors: Jeong, Jong-Moon, Murthy, S.N. Prasanna, Radek, James T., Lorand, Laszlo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 10.03.1995; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Sequence; Animals; Binding Sites; Chromatography, DEAE-Cellulose; Electrophoresis, Polyacrylamide Gel; Fibronectins - metabolism; Fluorescence Polarization; Guinea Pigs; Humans; Kinetics; Liver - enzymology; Molecular Sequence Data; Peptide Fragments - chemistry; Peptide Fragments - isolation & purification; Protein Conformation; Sequence Homology, Amino Acid; Transglutaminases - chemistry; Transglutaminases - isolation & purification; Transglutaminases - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.270.10.5654

Guinea pig liver transglutaminase (EC 2.3.2.13) displays a Ca2+-independent binding (Ka= 107M−1) to the same gelatin-binding domain of human plasma fibronectin that is known to form a very tight complex with the human red cell enzyme. The fibronectin-combining site of the liver transglutaminase was investigated by testing fragments obtained from the parent protein by controlled digestion with endoproteinase Lys-C. Overlay assays, probed with anti-fibronectin antibody, revealed that the fibronectin binding ability of the transglutaminase was encoded in a linear sequence in its 28-kDa N-terminal domain. Removal of the first 7 residues by further digestion of the purified 28-kDa material with endoproteinase Glu-C generated a 27-kDa fragment that, however, showed no binding activity. Thus, residues 1-7 in the liver enzyme seem to be of particular importance for influencing its ability to bind to fibronectin.