Cell surface human alpha-L-fucosidase

The acid alpha -L-fucosidase is usually found as a soluble component of lys osomes where fucoglycoconjugates are degraded. In the present investigation , we have demonstrated the existence of a cell surface protein with enzymat ic alpha -L-fucosidase activity that crossreacts specifically with a rabbit anti-(alpha -L-fucosidase) Ig. By different approaches, this alpha -L-fuco sidase, which represents 10-20% of the total cellular fucosidase activity, was detected in all the tested human cells (hemopoietic, epithelial, mesenc hymal). Two bands of approximate to 43-49 kDa were observed, although theor etical data support the possibility of having the same genetic origin that the known 50 to 55-kDa M-r alpha -L-fucosidase. We speculate about an alter native traffic pathway for the plasma membrane alpha -L-fucosidase to work on the rapid turnover of glycoproteins.