Occurrence of glycosidases and enzymatic properties of .BETA.-N-acetylhexosaminidases in the external mucous materials of various fishes.


Substantial glycosidase activities were found in all the external mucous materials of various fishes regardless of their habitats. β-N-Acetylhexosaminidase activity was the most dominant among glycosidase activities examined. Since β-N-acetylhexosaminidase occurred enough in the mucous materials to be isolated, individual, β-N-acetylhexosaminidases were purified from the mucousmaterials of eel, loach, and stingray and their enzymatic properties were compared. During the course of the purification, these enzymes behaved quite similarly on Sephadex G-200 gel filtra-tion and CM-cellulose chromatography. The molecular weights, pH optima, and pH stabilities of the enzymes were almost identical although the Km value of the stingray enzyme toward p-ninophenyl β-N-acetylglucosalminide differed from that of the other enzymes. The above facts do not support a possibility that the glycosidases may be a product of bacteria which live in the mucous material but strongly support a possibility that the enzymes may be a secretion from the fish skin.


榎本 則行 佐賀大学農学部
浅川 牧夫 通宝海苔(株)
浅川 牧夫 熊本大学教育学部食物学研究室
中川 浩毅 佐賀大学農学部
中川 浩毅 佐賀大学農学部生命機能科学科
浅川 牧夫 熊本大学教育学部