beatriz@pine.circa.ufl.edu (Beatriz Gonzalez-Yanes) (04/05/91)
Hello network researchers, In my research I do cell fractionation and use the enzyme markers alpha-glucosidase-2 for the ER and acid phosphatase for the lysosome. Somehow, I was assuming all along that these markers are luminal proteins, in other words, not attached to the membrane, of those organelles. Now I face not being able to find references to support my claim. I work with Dictyostelium discoideum and even though I have access to other enzyme marker assays, these are convenient because the reagents are pretty cheap and I have alreasy worked out a standard assay. We are interested in a protein that remains in the supernatant after 100k x g centrifugation, so we are assigning it a cytosolic compartmentalization. The amount of Acid phosph. and a-glucos-2 in the sup is minimal compare to the 100kxg pellet, but I am not able to release most of these markers by sonicating my extract before spinning, hence my doubts that they are luminal proteins. Any comments and references would be very much appreciated. Beatriz Gonzalez-Yanes bitnet beatriz@ufpine internet beatriz@pine.circa.ufl.edu