Abstract
Lecithin-cholesterol acyltransferase (EC 2.3.1.43) was purified from hog plasma by a highly efficient procedure. The final enzyme preparation was purified 30000-fold over the starting material and was homogeneous as indicated by polyacrylamide gel electrophoreses in the presence of both SDS and urea. The purified hog lecithin-cholesterol acyltransferase had an apparent molecular weight of 66000 on SDS-poly-acrylamide gel electrophoresis and HPLC and was found to contain about 21.4% (w/w) carbohydrate-hexose, 11.3%; hexosamine, 1.9%; sialic acid, 8.2%. The amino acid composition analysis showed that hog lecithin-cholesterol acyltransferase contains four half cystines per mol; two cysteines were titrated at neutral pH with 5,5'-dithiobis(2-nitrobenzoic acid). Nearly all the phenolic groups were unavailable to the solvent at neutral pH, while they become exposed at around pH 11. Hog lecithin-cholesterol acyltransferase was found to be associated with HDL in the plasma and it prefers HDL as a substrate. The physicochemical properties of hog lecithin-cholesterol acyltransferase were generally similar to those of the human and the rat enzyme.
Original language | English |
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Pages (from-to) | 179-190 |
Number of pages | 12 |
Journal | Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism |
Volume | 877 |
Issue number | 1 |
DOIs | |
State | Published - 11 Jun 1986 |
Keywords
- (Porcine)
- Amino acid composition
- Enzyme purification
- Lecithin-cholesterol acyltransferase