Title : Antibodies having markedly different effects on enzymatic activity and induction of acetylcholine release by two presynaptically-acting phospholipase A2 neurotoxins - Fletcher_1995_Biochem.Pharmacol_49_381 |
Author(s) : Fletcher JE , Jiang MS , Middlebrook JL |
Ref : Biochemical Pharmacology , 49 :381 , 1995 |
Abstract :
The enzymatic and acetylcholine-releasing activities of two presynaptically-acting phospholipase A2 neurotoxins (pseudexin B and scutoxin) were studied in a synaptosomal fraction. Scutoxin (100 nM) induced greater [14C]acetylcholine release than did pseudexin B (100 nM). Both toxins caused fatty acid production in the synaptosomal fraction, although pseudexin B was more active than scutoxin. One monoclonal antibody raised against pseudexin B (no 4) had no effect on the enzymatic activity of either pseudexin B or scutoxin. Two other monoclonal antibodies (no3 and no7), also raised against pseudexin B, antagonized the enzymatic activity of pseudexin B and scutoxin. Monoclonal antibody no3 was more effective than no7 in reducing the amount of acetylcholine released by the toxins, whereas no7 was more effective than no3 in reducing fatty acid production. Although antibody no3 caused complete inhibition of phospholipase A2 activity of pseudexin B on purified substrates, it only reduced phospholipase A2 activity by 35% in synaptosomes. These findings support the hypothesis that gross phospholipase A2 activity does not play a role in stimulation of acetylcholine release by the presynaptically-acting phospholipase A2 neurotoxins. |
PubMedSearch : Fletcher_1995_Biochem.Pharmacol_49_381 |
PubMedID: 7857325 |
Fletcher JE, Jiang MS, Middlebrook JL (1995)
Antibodies having markedly different effects on enzymatic activity and induction of acetylcholine release by two presynaptically-acting phospholipase A2 neurotoxins
Biochemical Pharmacology
49 :381
Fletcher JE, Jiang MS, Middlebrook JL (1995)
Biochemical Pharmacology
49 :381