Cells sialidase, membrane-bound

R. W. Egan, and M. M. Billah, Induction of lysosomal and plasma membrane-bound sialidases in human T-cells via T-eell receptor, Biochem. J., 380 (2004) 425 33. 

In studies with other systems, Glick et al. (1971) found sialidase, active toward fetuin, to be enriched in the lysosomal fraction of L cells Tulsiani and Carubelli (1971) found sialidase, active toward sialyllactose, not only enriched in lysomes isolated from rat mammary glands, but also in the soluble fraction Gielen et al. (1973) found a membrane-bound sialidase in leukocytes that was very active toward glycoproteins in the leukocyte homogenate and Bosmann (1974) found sialidase activity associated with the plasma membranes of human erythrocytes. Recently, Kishore et al. (1975) have reported the presence of a sialidase in Golgi isolated from rat liver. 

To date, little about the purification of sialidase from mammalian cells has been published. The membrane-bound sialidase must be solubilized before any of the usual purification procedures can be applied. The solubilized sialidase that has been purified probably is still associated with a small membrane fragment. The soluble enzyme can be readily concentrated by standard procedures. To determine the mechanism of action of the enzyme and its physical characteristics, it may eventually be necessary somehow to obtain sialidase in truly purified form. 

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