A protein that inhibits the re-uptake of 5-hydroxytryptamine into rat brain synaptosomes was isolated from the venom of the Sahara sand viper (Cerastes vipera) by gel filtration and reverse phase chromatography. It has a molecular weight of 13 739 Da and an 50 of about 50 nM for blocking uptake of 3H-5-HT into rat brain synaptosomes. It also augmented the responses to 5-HT in a smooth muscle preparation. It has phospholipase A2 activity, but it has no lytic activity as measured by its inability to release lactate dehydrogenase from rat brain synaptosomes. Determination of the N-terminal sequence revealed a similarity with a phospholipase A2 previously isolated from Cerastes cerastes venom.
- 5-ht uptake inhibitor
- cerastes vipera