PURIFICATION AND CALCIUM-DEPENDENCE OF TRANSGLUTAMINASES FROM SHEEP HAIR-FOLLICLES

To study the calcium sensitivity of sheep hair follicle transglutamina se, which was reportedly calcium-independent [H. W. Harding and G. E. Rogers, Biochemistry, 11, 2858-2863 (1972)], the enzyme was purified f rom a homogenate of merino sheep hair follicles and its calcium depend ence was examined, As a result of purification, two types of transglut aminases (DEAE-unabsorbed and absorbed transglutaminase, DU-TG and DA- TG, respectively) were obtained, The molecular mass of DU-TG was 77 an d 82kDa by SDS-PAGE and gel filtration, respectively, while that of DA -TG was 40 and 80 kDa. Each enzyme was obviously calcium dependent and contained (a) cysteine residue(s) in the active site, like other know n mammalian transglutaminases. Maximum activation of DU-TG and DA-TG w as observed at 1 and 0.1 mM CaCl2, respectively.