Photoaffinity labeling of the lysosomal neuraminidase from bovine testis.
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.
van der Horst
G T
GT
Department of Cell Biology and Genetics, Erasmus University, Rotterdam, The Netherlands.
Rose
U
U
Brossmer
R
R
Verheijen
F W
FW
D000345:Affinity Labels / Q000737:chemistry; D000818:Animals; D002417:Cattle; D008247:Lysosomes / Q000201:enzymology; D008297:Male; D008970:Molecular Weight; D009439:Neuraminidase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D010777:Photochemistry; D012794:Sialic Acids / Q000737:chemistry; D013737:Testis / Q000201:enzymology*; D001616:beta-Galactosidase / Q000378:metabolism
D000345:Affinity Labels; D012794:Sialic Acids; D009439:Neuraminidase; D001616:beta-Galactosidase