Separation of paraoxon and mipafox sensitive esterases by sucrose density gradient sedimentation

Paraoxon- and mipafox-sensitive phenyl valerate (PV) hydrolases found in chicken nervous tissue were solubilized by Triton X-100 and separated by sucrose density gradient centrifugation. Enzyme activity from chick embryo brain with properties of neurotoxic esterase (NTE, insensitive to 40 microM paraoxon, sensitive to 50 microM mipafox) migrated in a 9S peak.