舟山眼镜蛇毒蕈碱样多肽MP的部分理化性质测定

Biochemical characterization of the muscarinic peptide isolated from Naja atra venom

目的对舟山眼镜蛇毒蕈碱样多肽MP成分进行纯化及部分理化性质测定。方法采用色谱技术纯化蛇毒MP成分,质谱仪测定其相对分子质量(Mr);Edman降解法分析部分氨基酸序列,与已知成分比对;以卵磷脂为底物测定MP组分的磷脂酶A2活性;采用Bliss法测定MP对小鼠的急性毒性。结果 MP的Mr为13 260,其N端16位氨基酸序列为NLYQFKNMIQCTVPSR,与已知蛇毒磷脂酶A2基本一致,并具有较强的磷脂酶A2活性;腹腔注射MP对小鼠的LD50值为14.3 mg/kg。结论 MP为一种眼镜蛇毒磷脂酶A2。

Purpose To identify the property of the fraction of muscarinic peptide（MP） isolated from Naja atra venom by purifying and determining the biochemical charaterization. Methods MP was purified by column chromatography. Its molecular weight was determined by mass spectrometry. The partial amino acid sequence of MP was gained by Edman degradation analysis. Lecithin as substrate was used to meas- ure phospholipase A2 activity of MP. Bliss method was used to determine the acute toxicity of MP in mice. Results The molecular weight of MP was 13 260 D and its N-terminal 16 amino acid sequence was NLYQFKNMIQCTVPSR,which is consistent with the known venom phospholipase A2. MP also displayed a strong phospholipase A2 activity. The LD50 value was 14.3 mg/kg in mice by intraperitoneal injection of MP. Conclusion It is suggested that MP is a snake venom phospholipase A2.