Skins of filleted brown backed toadfish (L. gloveri),
were collected from the local fish processing factory,
Charmson Foods Co. (Busan, South Korea). They were
transported to the laboratory and stored at 20 C until
used. Skins were removed, descaled and residual meat
were removed manually. Then cleaned skin were washed
thoroughly with water and cut into small pieces. Pepsin
(1:10,000 units) powder was purchased from Junsei
Chemical Co. Ltd. (Tokyo, Japan). Lysyl endopeptidase
from Achromobacter lyticus (EC 3.4.21.50; 4.5 amidase
activity/mg protein) and porcine type I skin collagen
(Cellmatrix, LA) were bought from Wako Pure Chemical
Industries, Ltd. (Osaka, Japan). All other reagents
used were of analytical grade