Transglutaminase from hair follicle of guinea pig (crosslinking-fibrin-glutamyllysine-isoenzymes-purified enzyme).

Two transglutaminases are found in homogenates of the inner root sheaths of guinea pig hair-follicles. One is indistinguishable from the well-characterized liver transglutaminase [J. Biol. Chem., 246, 1093 (1971)]. The other, which is present in far greater quantity, has not been detected in other organs or tissues. Gel filtration and polyacrylamide gel electrophoresis studies indicate that the native hair-follicle enzyme, of molecular weight 54,000, is composed of two subunits of identical molecular weight. Specificity studies suggest that the intermolecular cross-linking of fibrin and fibrinogen that is catalyzed by this enzyme is a result of the formation of epsilon(gamma-glutamyl)lysine bonds. The probable participation of hair-follicle transglutaminase in the formation of these cross-links in the proteins of hair is discussed.