Sterol carrier protein2 (SCP2)-like protein in rat aorta.
Immunoblot analysis using affinity-purified antibody against sterol carrier protein2 (SCP2) showed that SCP2-like protein exists in 105,000 x g supernatant of rat aorta. Analysis of subcellular distribution of SCP2-like protein in rat aorta was determined with enzyme immunoassay (EIA). The highest level of SCP2-like protein was observed in cytosolic fraction, while the lowest level was in nuclear fraction. Analysis of marker enzymes in subcellular fractions showed that catalase, a marker enzyme of peroxisomes, leaked to cytosolic fraction to a significant extent during subcellular preparation, suggesting that SCP2-like protein in cytosolic fraction of rat aorta might be partially originated from peroxisomes. In vitro addition of homogenous SCP2 purified from rat liver dose-dependently stimulated the formation of [14C]cholesteryl esters from exogenously added [14C]cholesterol by acyl-CoA:cholesterol acyltransferase (ACAT) in microsomal preparation of rat aorta. However the addition of cytosolic fraction did not enhance cholesterol esterification by ACAT, most likely due to a markedly low level of SCP2-like protein in this fraction. The role of SCP2 in the formation of cholesteryl esters by ACAT in rat aorta was discussed.
Ban
T
T
Second Department of Internal Medicine, School of Medicine, Chiba University, Japan.
Hirai
A
A
Kino
T
T
Oeda
T
T
Fujiki
Y
Y
Tamura
Y
Y
Yoshida
S
S
D000818:Animals; D001011:Aorta / Q000737:chemistry*; D002352:Carrier Proteins / Q000302:isolation & purification*; D002788:Cholesterol Esters / Q000096:biosynthesis; D003600:Cytosol / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D008099:Liver / Q000737:chemistry; D008297:Male; D008861:Microsomes / Q000201:enzymology; D010940:Plant Proteins; D051381:Rats; D011919:Rats, Inbred Strains; D002785:Sterol O-Acyltransferase / Q000378:metabolism; D013261:Sterols; D013347:Subcellular Fractions / Q000737:chemistry
D002352:Carrier Proteins; D002788:Cholesterol Esters; D010940:Plant Proteins; D013261:Sterols; C072087:sterol carrier proteins; D002785:Sterol O-Acyltransferase