Study on Antineurotoxic Factor from the Serum of Bungarus Multicinctus

Abstract

An antineurotoxic factor which can partially neutralize the toxicity of β bungarotoxin (β-BuTx) was purified to homogeneity from the serum of B. multicinctus by ammonium sulfate precipitation, DEAE-32 cellulose chromatography and preparative discontinuous polyacrylamide gel electrophoresis (PAGE). The purified antineurotoxic factor shows a single band in PAGE and SDS-PAGE, whose electrophoretic mobility is in the region of α₂- or β-globulin. The molecular weight of the antineurotoxic factor is 75-85 KD estimated by SDS-PAGE and Sephadex G-150 gel filtration. The band of antineurotoxic factor in PAGE was stained pink with the PAS (periodic acid-Schiff) procedure. 0.12 g/kg antineurotoxic fraction can increase die LD₅₀ of β-BuTx from 0.05 mg/kg mouse i.p. to 0.102 mg/kg mouse i.p. The antineurotoxic factor also possesses β-BuTx PLA₂ enzymatic inhibition activity, which can decrease β-BuTx PLA₂ enzymatic activity from 6.5 IU/mg to 5 IU/mg. Sephadex G-150 gel filtration shows no formation of a stable complex between the β-BuTx and the antineurotoxic factor. In this paper, the authors successfully isolated one antineurotoxic factor from the serum of B. multicinctus and found it could partially neutralize the toxicity of β-BuTx and inhibit β-BuTx PLA₂ enzymatic activity. We also propose a self-protective mechanism in B. multicinctus.