Affinity of human erythrocyte transglutaminase for a 42-kDa gelatin-binding fragment of human plasma fibronectin.

AUTOR(ES)

Radek, J T

RESUMO

Complex formation between the human erythrocyte transglutaminase (protein-glutamine:amine gamma-glutamyltransferase, EC 2.3.2.13) and fibronectin or its fragments was examined by immunoanalytical procedures and by fluorescence polarization. A 42-kDa gelatin-binding structure, obtained from human plasma fibronectin by thermolytic digestion, showed as high an affinity for the cytosolic enzyme as the parent fibronectin chains themselves. A 21-kDa fragment comprising type I modules 8 and 9, the last two modules in the 42-kDa fragment, bound with an affinity 100-fold less than the 42-kDa fragment. Binding was remarkably specific and could be exploited for the affinity purification of transglutaminase directly from the hemoglobin-depleted erythrocyte lysate. In spite of the high affinity, it was possible to elute active enzyme from the 42-kDa fragment column with 0.25% monochloroacetic acid. This solvent might have general applicability in other systems involving separation of tightly bound ligands.

Documentos Relacionados

• Transformation-enhancing activity of gelatin-binding fragments of fibronectin.
• Isolation and characterization of gelatin-binding proteins from goat seminal plasma
• Subtilisin and cyanogen bromide cleavage products of fibronectin that retain gelatin-binding activity.
• Potential proteolytic activity of human plasma fibronectin.
• The 42-kDa coat protein of Andean potato mottle virus acts as a transcriptional activator in yeast