TY - JOUR
T1 - Distribution in spleen subcellular organelles of sialidase active towards natural sialoglycolipid and sialoglycoprotein substrates
AU - Schengrund, Cara Lynne
AU - Repman, Mary Ann
AU - Nelson, Joseph T.
N1 - Funding Information:
This work was supported by grant CA 14319 awarded by the National Cancer Institute, D.H.E.W.; and grant NS 08258 from the National Institute of Neurological and Communicative Diseases and Stroke.
PY - 1979/6/6
Y1 - 1979/6/6
N2 - A procedure was devised for the preparation of enriched populations of subcellular organelles from homogenized bovine spleen. The fractions obtained were characterized for arysulfatase, succinate dehydrogenase, UDPgalactosyltransferase and 5′-nucleotidase activities. The distribution of sialidase (acylneuraminyl hydrolase, EC 3.2.1.18) activity directed towards either endogenous substrate or exogenous ganglioside substrate suggests that it is enriched in the plasma membrane/microsomal fractions. Sialidase activity towards exogenous sialoglycoproteins, isolated from erythrocyte membranes, was enriched in the least dense of the plasma membrane/microsomal-containing fractions. The endogenous sialidase substrates were primarily the sialoglycolipids, hematoside and disialogangliosides. At the pH optimum, 3.8 and 37°C, release of endogeneous sialic acid was linear with time for 3 h. At the end of this time, 85% or more of the available endogenous substrate was hydrolyzed.
AB - A procedure was devised for the preparation of enriched populations of subcellular organelles from homogenized bovine spleen. The fractions obtained were characterized for arysulfatase, succinate dehydrogenase, UDPgalactosyltransferase and 5′-nucleotidase activities. The distribution of sialidase (acylneuraminyl hydrolase, EC 3.2.1.18) activity directed towards either endogenous substrate or exogenous ganglioside substrate suggests that it is enriched in the plasma membrane/microsomal fractions. Sialidase activity towards exogenous sialoglycoproteins, isolated from erythrocyte membranes, was enriched in the least dense of the plasma membrane/microsomal-containing fractions. The endogenous sialidase substrates were primarily the sialoglycolipids, hematoside and disialogangliosides. At the pH optimum, 3.8 and 37°C, release of endogeneous sialic acid was linear with time for 3 h. At the end of this time, 85% or more of the available endogenous substrate was hydrolyzed.
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U2 - 10.1016/0005-2744(79)90306-1
DO - 10.1016/0005-2744(79)90306-1
M3 - Article
C2 - 486491
AN - SCOPUS:0018750678
SN - 0005-2744
VL - 568
SP - 377
EP - 385
JO - BBA - Enzymology
JF - BBA - Enzymology
IS - 2
ER -