The role of cationic amino acid residues in the lethal activity of stonustoxin from stonefish (Synanceja horrida) venom.
Stonustoxin (SNTX) is a two subunit pore-forming cytolytic protein purified from the venom of the stonefish (Synanceja horrida). SNTX also possesses lethal activity. Since cationic residues contribute significantly to the cytolytic activity of several pore-forming toxins, we examined the role of lysine and arginine residues in the lethal activity of SNTX. SNTX lost its lethal activity when the positively-charged side chains of lysine residues were converted to negatively-charged side chains upon succinylation. When the arginine residues were modified using 2,3-butanedione, SNTX also lost its lethal activity. However, the domains for cytolytic and lethal activity may not necessarily be the same.
Khoo
H E
HE
Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore.
Chen
D
D
Yuen
R
R
D000818:Animals; D001120:Arginine; D005397:Fish Venoms / Q000737:chemistry* / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000737:chemistry / Q000633:toxicity*; D007928:Lethal Dose 50; D008239:Lysine; D008297:Male; D051379:Mice; D013329:Structure-Activity Relationship
D005397:Fish Venoms; D006460:Hemolysin Proteins; C073228:stonustoxin; D001120:Arginine; D008239:Lysine