title: An EDTA.Ca2+ complex inhibits the enzymatic activity but not the lethality of beta-bungarotoxin.
abstract: An EDTA.Ca2+ complex inhibits the phospholipase A2 activity of the presynaptic neurotoxin beta-bungarotoxin without affecting its lethal potency. The EDTA.Ca2+ complex induces a conformational change in the enzymatic active site region of beta-BuTx, as indicated by the suppression of the 340 nm tryptophan fluorescence peak. Modification of the enzymatic site without loss of toxicity supports the presence of separate loci for the two activities.
authors: Felsenstein Medical Research Center, Petah Tikva, Israel.
authors: R
authors: R
authors: Shina
authors: P
authors: P
authors: Rosenberg
authors: E
authors: E
authors: Condrea
mesh_terms: D000818:Animals; D002038:Bungarotoxins / Q000037:antagonists & inhibitors* / Q000633:toxicity; D002118:Calcium / Q000494:pharmacology*; D004492:Edetic Acid / Q000494:pharmacology*; D006868:Hydrolysis; D066298:In Vitro Techniques; D008297:Male; D010741:Phospholipases A / Q000037:antagonists & inhibitors* / Q000633:toxicity; D054467:Phospholipases A2; D010743:Phospholipids / Q000737:chemistry; D011487:Protein Conformation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013050:Spectrometry, Fluorescence; D013574:Synaptosomes / Q000187:drug effects / Q000201:enzymology
chemical_list: D002038:Bungarotoxins; D010743:Phospholipids; D004492:Edetic Acid; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium