Abnormalities in lipoproteins of d < 1.006 g/ml in familial lecithin:cholesterol acyltransferase deficiency
| Autor: | Carolyn D. Mitchell, Weiling C. King, Egil Gjone, Kaare R. Norum, John A. Glomset, Trudy M. Forte, Kenneth R. Applegate |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1980 |
| Předmět: |
Intermediate-density lipoprotein
medicine.medical_specialty Lecithin cholesterol acyltransferase deficiency Apolipoprotein B biology Cholesterol Blood lipids Cell Biology QD415-436 medicine.disease Biochemistry chemistry.chemical_compound Endocrinology chemistry Internal medicine Cholesterylester transfer protein medicine biology.protein Cholesteryl ester lipids (amino acids peptides and proteins) Lipoprotein |
| Zdroj: | Journal of Lipid Research, Vol 21, Iss 8, Pp 1116-1127 (1980) |
| ISSN: | 0022-2275 |
| Popis: | Studies of different sized lipoproteins of d < 1.006 g/ml from patients with familial 1ecithin:cholesterol acyltransferase deficiency have yielded new evidence of abnormalities in this lipoprotein class. Lipoproteins of all sizes contain high amounts of unesterified cholesterol, low amounts of total protein, and particularly low amounts of apolipoproteins C-I1 and C-111. Lipoproteins 60 nm in diameter or larger include particles that show a notched appearance upon electron microscopy, and contain a) a high combined volume of phospholipid, unesterified cholesterol, and protein; b) high amounts of cholesteryl ester and apolipoproteins C-I and E, and c) two major tetramethylurea-insoluble proteins that can be separated by electrophoresis in the presence of sodium dodecyl- sulfate. In contrast, lipoproteins that are 40 nm in diameter or less appear to contain low amounts of cholesteryl ester, normal amounts of apolipoproteins GI and E, and a single tetrameth~lurea-irisoluble protein the size of that in control lipoproteins. Since these abnormalities occur in the lipo- proteins of four different patients from four different families, the); are probably effects of'the enzyme deficiency. Most, however, appear to arise indirectly because in vitro experiments published earlier indicate that fe\v are re- versed by incubation in the presence of the enzymc and patient high densit) lipoproteins-Glomset, J. A., K. Applegate, T. Forte, W. C. King, C. D. Mitchell, K. R. Norum, and E. Gjone. Abnormalities in lipoproteins of d < 1.006 giml in familial lecithin:cholesterol acyltrans- ferase deficiency.,/. Lipid Re\. 1980. 21: 11 16- 1125. lipoproteins of d < 1.006 giml increased nearly three- fold and that of apolipoprotein E (apoE) increased almost five-fold, while the contents of individual C apolipoproteins decreased by one-fourth to one-half. These observations raised the possibility that LCAT normally contributes to plasma lipoprotein metabolism not only by forming CE, but also by affecting the distribution of apolipoproteins between lipoproteins of d < 1.006 g/ml and HDL. One question that re- mained was whether the changes in apolipoprotein distribution caused by incubating patient plasma with LCAT corrected or exacerbated abnormalities in the native lipoproteins. Information was not available concerning the content of CE and apolipoproteins in individual subfractions of lipoproteins of d < 1.006 giml. The question seemed important, since a number of the abnormalities in familial LC4T deficiency appear to he only indirect effects of the enzyme lack (2). .4s a step toward understanding the mechanisms by Jvhich LCAT might normally control the distribu- tion of apolipoproteins in plasma, lie decided to characterize the distribution of apoC and apoE in patient lipoproteins of d < 1.006 giml. We studied four patients from different families, \vho shelved different degrees of hypertriglyceridemia and renal dysfunction. We isolated their plasma lipoproteins of d < 1.006 giml by preparative ultracentrifugation, subfractionated the lipoproteins by gel filtration on 'I7 2 /cm agarose, analyzed the content of lipids and apo |
| Databáze: | OpenAIRE |
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