Occurrence of sialidase activity in two distinct and highly homogeneous populations of lysosomes prepared from the brain of developing mouse

FEBS Letters

Chiarini, Anna¹  Siniscalco, Carola¹  Fiorilli, Amelia¹  Venerando, Bruno¹  Di Francesco, Lucia¹  Tettamanti, Guido¹ 

[1]Study Center for the Functional Biochemistry of Brain Lipids, Department of Medical Chemistry and Biochemistry, The Medical School, University of Milan, Milan, Italy

关键词: Brain development;    Sialidase;    Lysosome;    Subcellular fractionation;   

DOI  :  10.1016/0014-5793(91)80485-L

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Light and heavy lysosomes of mouse forebrain were separated from each other by centrifugation on a Percoll gradient. Light lysosomes were then freed from mitochondria and membranes by sucrose density gradient centrifugation and further purified by floatation-centrifugation on a sucrose gradient. The final preparations of light and heavy lysosomes, fairly homogenous, carried sinlidase activity, assayed on MU-NeuAc. The optimal pH was 4.0 and 4.2, the apparent K_m value 2.8 × 10⁻³ M and 4.2 × 10⁻³ M and the apparent V _max value 0.11 and 0.47 mU mg⁻¹ protein, for the light and heavy lysosome sialidase, respectively. From 4 days to adulthood the specific activity of the light and heavy lysosome sialidase increased 3-fold and 1.7-fold, respectively.

【 授权许可】

Unknown