Document Detail

Antibodies having markedly different effects on enzymatic activity and induction of acetylcholine release by two presynaptically-acting phospholipase A2 neurotoxins.
MedLine Citation:
PMID:  7857325     Owner:  NLM     Status:  MEDLINE    
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 (#4) had no effect on the enzymatic activity of either pseudexin B or scutoxin. Two other monoclonal antibodies (#3 and #7), also raised against pseudexin B, antagonized the enzymatic activity of pseudexin B and scutoxin. Monoclonal antibody #3 was more effective than #7 in reducing the amount of acetylcholine released by the toxins, whereas #7 was more effective than #3 in reducing fatty acid production. Although antibody #3 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.
J E Fletcher; M S Jiang; J L Middlebrook
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Biochemical pharmacology     Volume:  49     ISSN:  0006-2952     ISO Abbreviation:  Biochem. Pharmacol.     Publication Date:  1995 Jan 
Date Detail:
Created Date:  1995-03-14     Completed Date:  1995-03-14     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0101032     Medline TA:  Biochem Pharmacol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  381-8     Citation Subset:  IM    
Department of Anesthesiology, Hahnemann University, Philadelphia, PA 19102-1192.
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MeSH Terms
Acetylcholine / biosynthesis*
Antibodies / pharmacology*
Brain Chemistry
Elapid Venoms / immunology,  pharmacology
Enzyme Activation / drug effects
Fatty Acids / analysis
Neurotoxins / immunology,  pharmacology*
Phospholipases A / antagonists & inhibitors,  metabolism*
Phospholipases A2
Synaptosomes / drug effects
Reg. No./Substance:
0/Antibodies; 0/Elapid Venoms; 0/Fatty Acids; 0/Neurotoxins; 0/Pseudechis venom; 132444-97-4/scutoxin A; 51-84-3/Acetylcholine; EC 3.1.1.-/Phospholipases A; EC A2

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