A novel cysteine protease inhibitor with lectin activity from the epidermis of the Japanese eel Anguilla japonica.
A novel cysteine protease inhibitor (Eel-CPI-1) was isolated from the epidermis of the eel. Eel-CPI-1 was shown to bind strongly to both lactose- and carboxymethylated papain-affinity gels. Its molecular mass under reducing condition was determined to be 18 kDa by SDS-polyacrylamide gel electrophoresis but approximately 30.5 kDa under non-reducing-conditions. Eel-CPI-1 inhibited papain (K(i)=18 nM) and ficin (K(i)=120 nM) competitively. Combined with the data on amino acid and sequence analysis, Eel-CPI-1 is identical to the eel lectin, AJL-2. This is the first report describing a cysteine protease inhibitor with lectin activity.
Saitoh
Eiichi
E
Department of Biochemistry, The Nippon Dental University School of Dentistry at Niigata, 1-8 Hamaura-cho, Niigata 951-8580, Japan. esaitoh@ngt.ndu.ac.jp
Isemura
Satoko
S
Chiba
Akira
A
Oka
Shunya
S
Odani
Shoji
S
D000818:Animals; D001419:Bacteria / Q000201:enzymology; D015853:Cysteine Proteinase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D004524:Eels; D004817:Epidermis / Q000737:chemistry*; D005361:Ficain / Q000037:antagonists & inhibitors; D007700:Kinetics; D037102:Lectins / Q000494:pharmacology; D010206:Papain / Q000037:antagonists & inhibitors
D015853:Cysteine Proteinase Inhibitors; D037102:Lectins; D010206:Papain; D005361:Ficain