Morphologic and biochemical heterogeneity of lysosomes
Pokrovskiĭ, A.A.; Krystev, L.P.; Tutel'ian, V.A.; Kravchenko, L.V.; Boiadzhieva, Z.K.
Tsitologiia 17(8): 954-959
1975
ISSN/ISBN: 0041-3771 PMID: 1231099 Document Number: 85983
By means of isopycnic centrifugation in the continuous density gradient of sucrose two subfractions of lysosomes were isolated from rat liver homogenates: a "light" one (with the floating density p=1.13) and a "heavy" one (p=1.24). Electron microscopic, enzymatic and electron microscope enzymatic analysis of the isolated subfractions showed that the "light" subfraction consisted mainly of newly-formed primary lysosomes, while the "heavy" one was presented by secondary lysosomes. Parallel biochemical investigations demonstrated a considerable enzymatic heterogeneity of the two lysosomal subfractions: the "light" subfraction was characterized by a high specific activity of acid DNase, acid RNase and beta-galactosidase, and by almost total absence of beta-glucosidase activity, while the "heavy" one was characterized by a high specific activity of beta-glucosidase, beta-glucuronidase and beta-N-acetylglucosaminidase. Possible causes of enzyme heterogeneity of rat liver lysosomes are discussed.