Marshall R, Quinn L Y
J Bacteriol. 1967 Oct;94(4):812-4. doi: 10.1128/jb.94.4.812-814.1967.
Type A botulinum toxin was studied for its ability to inhibit the action of acetyl-cholinesterase. The chromogenic substrate, indophenyl acetate, was used for assay of enzyme activity. Inhibition of enzyme function was detected through use of both 6.6 x 10(-6) mg (20 ld(50)) and 6.6 x 10(-10) mg (2 x 10(-3)ld(50)) of type A botulinal toxin. Control assays were performed by use of both homologous antitoxin and heterologous antitoxins (types B and E). Enzyme inhibition was effectively prevented by use of homologous antitoxin only. The inhibition noted was specific and reproducible for given substrate, enzyme, and toxin concentrations.
研究了A型肉毒杆菌毒素抑制乙酰胆碱酯酶作用的能力。使用生色底物乙酸吲哚苯酯来测定酶活性。通过使用6.6×10⁻⁶毫克（20个半数致死量）和6.6×10⁻¹⁰毫克（2×10⁻³个半数致死量）的A型肉毒杆菌毒素检测酶功能的抑制情况。对照试验使用同源抗毒素和异源抗毒素（B型和E型）进行。仅使用同源抗毒素可有效防止酶抑制。对于给定的底物、酶和毒素浓度，所观察到的抑制是特异性且可重复的。
