β-hexosaminidase from Xenopus laevis eggs and oocytes: From gene to immunochemical characterization
Article first published online: 9 OCT 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Cellular Biochemistry
Volume 113, Issue 12, pages 3709–3720, December 2012
How to Cite
Morales, E. S., Krapf, D., Botta, P. E., Cabada, M. O. and Arranz, S. E. (2012), β-hexosaminidase from Xenopus laevis eggs and oocytes: From gene to immunochemical characterization. J. Cell. Biochem., 113: 3709–3720. doi: 10.1002/jcb.24244
- Issue published online: 9 OCT 2012
- Article first published online: 9 OCT 2012
- Accepted manuscript online: 2 JUL 2012 07:21AM EST
- Manuscript Accepted: 22 JUN 2012
- Manuscript Received: 8 NOV 2011
- National Agency of Argentina for Scientific and Technological Promotion of Science PICT. Grant Number: 15-31660
- National Research Council of Argentina (CONICET). Grant Number: PIP6428
- BLOCK TO POLYSPERMY;
Glycosidases are present both in sperm and eggs in vertebrates and have been associated with different fertilization steps as gamete binding, egg coat penetration, and polyspermy prevention. In this manuscript, we have analyzed the activity of different glycosidases of Xenopus laevis eggs. The main activity corresponded to N-acetyl-β-D-glucosaminidase (Hex), which was reported to participate both in gamete binding and polyspermy prevention among phylogenetically distant animals. We have raised homologous antibodies against a recombinant N-terminal fragment of a X. laevis Hex, and characterized egg's Hex both by Western blot and immunohistochemical assays. Noteworthy, Hex was mainly localized to the cortex of animal hemisphere of full-grown oocytes and oviposited eggs, and remained unaltered after fertilization. Hex is constituted by different pair arrangements of two subunits (α and β), giving rise to three possible Hex isoforms: A (αβ), B (ββ), and S (αα). However, no information was available regarding molecular identity of Hex in amphibians. We present for the first time the primary sequences of two isoforms of X. laevis Hex. Interestingly, our results suggest that α- and β-like subunits that constitute Hex isoforms could be synthesized from a same gene in Xenopus, by alternative exon use. This finding denotes an evolutionary divergence with mammals, where α and β Hex subunits are synthesized from different genes on different chromosomes. J. Cell. Biochem. 113: 3709–3720, 2012. © 2012 Wiley Periodicals, Inc.