Nonradioactive immunoquantification of alpha-L-fucosidase protein in human colon tissues

alpha-L-Fucosidase is a glycosidase involved in the degradation of fucoglycoconjugates and has a diagnostic significance because it has been described to be altered in several known diseases. However, in vitro studies on enzymatic activities may not reflect the real protein levels in tissues. This paper describes a simple method to quantify alpha-L-fucosidase protein levels in human crude extracts, combining the slot-blot technique and a nonradioactive immunoassay. Taking advantage of the similarities in different mammalian fucosidases, a polyclonal antiserum was raised against commercial purified alpha-L-fucosidase from bovine kidney that cross-reacted with the human colon enzyme. The method is able to detect as little as 0.75 ng alpha-L-fucosidase. To illustrate the direct application of this technique, we analysed and quantified alpha-L-fucosidase protein levels in 18 human colon crude samples. This technique could prove useful in clinical pathology, allowing fast and accurate measurement of alpha-L-fucosidase in crude extracts.