Novel Reticular Calcium Binding Protein Is Purified on Taipoxin Columns
Article first published online: 23 NOV 2002
Journal of Neurochemistry
Volume 64, Issue 5, pages 2339–2344, May 1995
How to Cite
Dodds, D., Schlimgen, A. K., Lu, S.-Y. and Perin, M. S. (1995), Novel Reticular Calcium Binding Protein Is Purified on Taipoxin Columns. Journal of Neurochemistry, 64: 2339–2344. doi: 10.1046/j.1471-4159.1995.64052339.x
- Issue published online: 23 NOV 2002
- Article first published online: 23 NOV 2002
- Received September 9, 1994; revised manuscript received October 24, 1994; accepted November 7, 1994.
- Snake venom;
- Neuronal pentraxin;
- Endoplasmic reticulum
Abstract: We identified, by affinity chromatography, two putative binding proteins for the presynaptic snake venom toxin taipoxin. We have previously characterized one of these proteins [neuronal pentraxin (NP)] as a neuronally secreted protein with homology to acute-phase proteins. Here we report the identification of the second protein as a 49-kDa lumenal calcium binding protein that we have named taipoxin-associated calcium binding protein 49 (TCBP-49). This protein contains six EF-hand putative calcium binding domains and the carboxyl-terminal sequence His-Asp-Glu-Leu (HDEL), identical to the yeast endoplasmic reticulum retention signal. Message for this protein is present in brain, liver, muscle, heart, kidney, and testis. Antibodies to this protein label reticular organelles of neurons and glia. This localization and the specific enrichment of native and recombinant TCBP-49 on columns of immobilized taipoxin raise the possibility that this protein interacts with internalized taipoxin, perhaps mediating its activation. The availability of pure TCBP-49 will allow direct tests of whether TCBP-49 alters the integrity of the oligomeric structure, phospholipase activity, or toxicity of taipoxin.