Transglutaminase from Hair Follicle of Guinea Pig

Abstract

Two transglutaminases are found in homogenates of the inner root sheaths of guinea pig hairfollicles. One is indistinguishable from the well-characterized liver transglutaminase [J. Biol. Chem., 246, 1093]. 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 e(y-glutamyl)lysine bonds. The probable participation of hair-follicle transglutaminase in the formation of these cross-links in the proteins of hair is discussed.The essential role in protein structure of intramolecular covalent crosslinks, in the form of disulfide bonds, has been recognized for many years (ref. 1 for review). There is an increasing awareness of the physiological importance of other covalent crosslinks, within and between protein molecules. Two types of chemical bonds are known to comprise these crosslinks. One, which occurs in collagen and elastin, is the combination of lysine-and hydroxylysine-derived aldehyde condensation products and Shiff bases formed by coupling of these aldehydes with e-amino groups (ref. 2 for review). The second is the e(-y-glutamyl)lysine amide bonds formed during the stabilization of fibrin clot (3-5), and reported to occur in cultures of chicken-breast muscle (6), I-cell membrane (6), native wool keratin (7), and the citrulline-containing protein fraction of hair (8).Work in this laboratory has centered on guinea pig liver transglutaminase, an enzyme that catalyzes formation of -y-glutamyl amide bonds (9, 10) by way of an acyl-transfer mechanism (I1). The wide occurrence and obvious importance of y-glutamyl amide bonds has led us to focus attention on the various enzymes responsible for their formation. Transglutaminases derived from plasma and platelet protransglutaminases (blood coagulation Factor XIII) through thrombin activation (ref. 12 for review) are responsible for the stabilization of fibrin clot, a consequence of formation of e(yglutamyl)lysine bridges between fibrin monomers. Purified transglutaminase from guinea pig liver stabilizes both fibrin (13) and fibrinogen (14) The other, which is present in far greater quantity, is distinctly different from previously described enzymes, and is the principal subject of this paper. MATERIALS AND METHODSSkins from 20-to 25-week-old guinea pigs were obtained packed in dry ice from Rockland (Gilbertsville, Pa. RESULTS Isolation of enzymesStep 1. Hair follicles of the guinea pig were,exposed by the wax-sheet method (17, 18) with a beeswax-rosin mixture at a temperature not exceeding 55°C. The inner-root sheaths were

Proteomic Analysis of Human Nail Plate

“…Based on original work on wool and hair in animal models, trapping of protein constituents in insoluble complexes was attributed to the action of transglutaminases found in the hair follicle [11, 12], analogous to the action of factor XIIIa in blood clotting [13]. Studying the biochemical basis for the cross-linking process was assisted by the discovery that it is manifested in cultures of human epidermal cells [14].…”

Calpain inhibitors reduce the cornified cell envelope formation by inhibiting proteolytic processing of transglutaminase 1

“…This could be related with an in vitro experiment that demonstrated the increase of GTPase activity by specific truncation (Lai e t a l., 1996). TGase 3 is expressed on the upper granular layer to complete CE formation (Chung and Folk, 1972;Negi et al, 1985;Kim et al, 1990). Proteolysis of TGase 3 is involved in the active form which showed a 60 times higher activity than the pre-form (Kim et al .…”

Induction of keratinocyte type-I transglutaminase in epithelial cells of the rat

“…They are secreted in plasma [4,25,301 and seminal fluid [51], expressed as soluble intracellular enzymes in peripheralblood cells [13, 361, lens [26], epidermis [5, 321, hair follicles [9,201, and numerous other tissues [8], and expressed as particulate enzymes in rat lung [lo, 191, lens [2], and liver [7,461, as well as in cell lines from various sources [3]. These types constitute a family of distinct enzymes, as judged by their biochemical properties [I61 and the regulation of their synthesis by physiological agents such as vitamin A, cyclic AMP, hydrocortisone, and calcium [13,24,42,491.…”