van der Horst G T, Rose U, Brossmer R, Verheijen F W
Department of Cell Biology and Genetics, Erasmus University, Rotterdam, The Netherlands.
FEBS Lett. 1990 Dec 17;277(1-2):42-4. doi: 10.1016/0014-5793(90)80805-s.
ASA-NeuAc2en, a photoreactive arylazide derivative of sialic acid, is shown to be a powerful competitive inhibitor of lysosomal neuraminidase from bovine testis (Ki approximately 21 microM). 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 beta-galactosidase/neuraminidase/protective protein complex contains the catalytic site of neuraminidase.
