ASA-NeuAc2en, a photoreactive arylazide derivative of sialic acid, is shown to be a powerful competitive inhibitor of lysosomal neuraminidase from bovine testis (Ki ≈ 21 μM). Photoaffinity labeling and partial purification of preparations containing this lysosomal neuraminidase activity result in specifically and non-specifically labeled polypeptides. Only labeling in a 55 kDa polypeptide is found to be specific, since it could be prevented by the competitive neuraminidase inhibitor NeuAc2en. We conclude that the 55 kDa polypeptide in the bovine testis β-galactosidase/neuraminidase/protective protein complex contains the catalytic site of neuraminidase.

doi.org/10.1016/0014-5793(90)80805-S, hdl.handle.net/1765/57907
F E B S Letters
Department of Clinical Genetics

van der Horst, G., Rose, U., Brossmer, R., & Verheijen, F. (1990). Photoaffinity labeling of the lysosomal neuraminidase from bovine testis. F E B S Letters, 277(1-2), 42–44. doi:10.1016/0014-5793(90)80805-S