Purification of very high density lipoproteins by differential density gradient ultracentrifugation

1987 ◽  
Vol 161 (2) ◽  
pp. 307-310 ◽  
Author(s):  
Norbert H. Haunerland ◽  
Robert O. Ryan ◽  
John H. Law ◽  
William S. Bowers
Lipids ◽  
1978 ◽  
Vol 13 (1) ◽  
pp. 88-91 ◽  
Author(s):  
Jerome L. Hojnacki ◽  
Robert J. Nicolosi ◽  
Norma Llansa ◽  
K. C. Hayes

1983 ◽  
Vol 244 (5) ◽  
pp. E513-E516 ◽  
Author(s):  
A. R. Tall ◽  
C. B. Blum ◽  
S. M. Grundy

The incorporation of orally administered phospholipid into plasma high-density lipoproteins (HDL) was studied in three subjects. Plasma was analyzed by equilibrium density gradient ultracentrifugation, 5, 6, and 8 h after ingestion of 1.1 g [3H-choline, 14C-dilinoleoyl]phosphatidylcholine. At all time points in all subjects, there was a peak of phosphatidylcholine specific activity in fractions of density approximately 1.10-1.13 g/ml, corresponding to the subclass previously designated HDL2a. There was also a more variable, smaller peak of specific activity of phospholipids in HDL2b (1.063-1.100 g/ml) and in fractions of density approximately 1.19 g/ml. In the 1.10-1.13 fraction, 97 and 71%, respectively, of the 3H and 14C radioactivity were in phospholipids. The 3H/14C ratio was similar in phospholipids of HDL subfractions, the d less than 1.07 fraction, and in the administered phospholipid. The results show preferential transfer or exchange or absorbed phosphatidylcholine into specific subclasses of HDL.


Biochemistry ◽  
1966 ◽  
Vol 5 (12) ◽  
pp. 4044-4053 ◽  
Author(s):  
Petar Alaupovic ◽  
Shafeek S. Sanbar ◽  
Robert H. Furman ◽  
Michael L. Sullivan ◽  
Sandra L. Walraven

1999 ◽  
Vol 202 (13) ◽  
pp. 1819-1829 ◽  
Author(s):  
T. Ravid ◽  
A. Tietz ◽  
M. Khayat ◽  
E. Boehm ◽  
R. Michelis ◽  
...  

By the end of oocyte development, the ovaries of Penaeus semisulcatus have accumulated almost equal amounts (approximately 16 mg lipid g-1 protein) of phospholipids and triacylglycerols. The phospholipids consist mainly of phosphatidylcholine (75–80 %) and phosphatidylethanolamine (20–25 %). Approximately 30 % of the total fatty acid content of both phospholipids and triacylglycerols is made up of polyunsaturated fatty acids. In fractions obtained by centrifugation of ovarian homogenates, most of the increase in levels of ovarian lipids during ovarian maturation was associated with an increase in triacylglycerol levels in the floating fat fraction and of phospholipids in the infranatant fraction. The presence of polyunsaturated fatty acids in the ovaries indicates the occurrence of lipid transport to the ovary during oocyte maturation. The gradual decrease in the relative abundance of polyunsaturated fatty acids as the ovaries matured supports previously published results suggesting intra-ovarian synthesis of saturated and mono-unsaturated fatty acids. Most of the lipids found in the female haemolymph (64.8 %) were recovered in the high-density lipoprotein fraction after density ultracentrifugation. The haemocyanin fraction recovered from this stage of fractionation contained substantial amounts of lipid (16.8 %) that could be removed by further sequential centrifugation at a higher NaBr density, leaving less than 0.9 % of the total haemolymph lipids associated with this fraction. While 16.2 % of the lipids were recovered from the very high-density lipoprotein fractions, these lipoproteins carried only 64–89 microg lipid mg-1 protein compared with 538.9 microg lipid mg-1 protein in the high-density lipoprotein fraction, indicating that the high-density lipoproteins are more likely to be the main transporters of lipids to the ovary. However, the contribution of very high-density lipoproteins to lipid transport cannot be ruled out at this stage. In this study, we present two models for lipid transport to the ovary based on the abundance of phospholipids and triacylglycerols in the haemolymph and on the amounts of polyunsaturated fatty acids accumulated within the ovary during vitellogenesis.


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