Nikai T, Imai K, Sugihara H, Tu A T
Department of Microbiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan.
Arch Biochem Biophys. 1988 Jul;264(1):270-80. doi: 10.1016/0003-9861(88)90594-2.
A hemorrhagic toxin with lethal and arginine ester hydrolytic activities was isolated from Heloderma horridum (beaded lizard) venom by Sephadex G-75, DEAE-Sephacel, and Q-Sepharose column chromatography. The hemorrhagic toxin was shown to be homogeneous as demonstrated by a single band on acrylamide gel electrophoresis and immunodiffusion. Its molecular weight is approximately 31,000 with an isoelectric point of 3.9. Hemorrhagic, lethal, and benzoyl-L-arginine ethyl ester hydrolytic activities of this preparation were inhibited by diisopropyl fluorophosphate (DFP), N-bromosuccinimide, and beta-mercaptoethanol, suggesting that serine, tryptophan, and disulfide bonds are involved in these activities. Also there was an increase in creatine kinase activity in mice serum which is an indicator that the toxin is involved in muscle damage. This protein was stable to heat and pH ranges between 2 and 11. The Michaelis constant (Km), for benzoyl-L-arginine ethyl ester, and inhibition constant (Ki), for DFP, were found to be 6.9 X 10(-3) and 1.93 X 10(-4) M, respectively.
通过Sephadex G - 75、DEAE - Sephacel和Q - Sepharose柱色谱法从珠毒蜥（Heloderma horridum）毒液中分离出一种具有致死和精氨酸酯水解活性的出血毒素。如丙烯酰胺凝胶电泳和免疫扩散显示的单一条带所示，该出血毒素被证明是均一的。其分子量约为31,000，等电点为3.9。二异丙基氟磷酸酯（DFP）、N - 溴代琥珀酰亚胺和β - 巯基乙醇抑制了该制剂的出血、致死和苯甲酰 - L - 精氨酸乙酯水解活性，表明丝氨酸、色氨酸和二硫键参与了这些活性。此外，小鼠血清中的肌酸激酶活性增加，这表明该毒素与肌肉损伤有关。这种蛋白质在2至11的温度和pH范围内对热稳定。苯甲酰 - L - 精氨酸乙酯的米氏常数（Km）和DFP的抑制常数（Ki）分别为6.9×10⁻³和1.93×10⁻⁴ M。
