ALPHA AND BETA BUNGAROTOXIN BINDING PROTEINS IN HUMAN CADAVER MUSCLE

Abstract

The nicotinic acetylcholine receptors (nAChR) in skeletal muscle, which are targets of the autoimmune response that cause myasthenia gravis (MG). MG is an autoimmune disease caused by anti-acetylcholine (anti-AChR) antibodies, resulting in functional loss of AChR at the neuromuscular junction. Specific binding of radio-iodinated α and β Bgtx was carried out in membranes (rapid filtration method) and triton extract (ammonium sulfate precipitation method) of fresh muscle. The specific binding of α Bgtx to membranes and triton extract of fresh muscle was found to be 19.8 ± 0.2 and 10.2 ± 0.12 fmoles/mg tissue, respectively whereas the same for β-Bgtx was found to be 10.2 ± 0.15 and 7.2 ± 0.12 fmoles/mg tissue, respectively. It was observed that there was no significant decline in specific binding to membranes and triton extract of muscle with increase in post-mortem time from 5 to 24 h. By indirect ELISA with MG pool sera, in addition to age the immunoreactivity varies from one cadaver to another. It was observed that β bungarotoxin binding proteins in muscle shows high immunoreactivity as compared to α Bungarotoxin binding protein.