Rat heart lipoprotein lipase

Twu, Jer-Shung; Garfinkel, Arlene S.; Schotz, Michael C.

doi:10.1016/0021-9150(75)90025-8

Cited by 44 publications

(20 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presumed function of the enzyme is the hydrolysis of triglycerides in intermediate density lipoproteins (IDL) and of phospholipids in high density lipoproteins (HDL2) (5). The capacity ofpurified hepatic lipase to catalyze hydrolysis of phospholipids and mono-, di-, and triglycerides (6,7) is consistent with the putative function. The action of hepatic lipase on HDL2 is presumed to result in the production of HDL3.…”

mentioning

confidence: 60%

“…The enzyme has an apparent molecular weight of53,000 (7,11) cDNA Screening and Analysis. Partial amino acid sequences were determined from the digestion of purified hepatic lipase with subtilisin (11).…”

Section: Introductionmentioning

confidence: 99%

“…Hepatic lipase from rat liver has been purified to homogeneity (7,10). The enzyme has an apparent molecular weight of53,000 (7,11) and contains approximately 8% carbohydrate (12).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Cloning of rat hepatic lipase cDNA: evidence for a lipase gene family.

Komaromy¹,

Schotz²

1987

Proc. Natl. Acad. Sci. U.S.A.

145

View full text Add to dashboard Cite

Clones for rat hepatic lipase were isolated by probing a rat liver cDNA library in Agtll with an oligonucleotide synthesized on the basis of a partial peptide sequence. The cloned messenger codes for a protein of 472 amino acids plus a hydrophobic leader sequence of 22 amino acids. The unglycosylated protein has a predicted molecular weight of 53,222 and contains two potential sites for N-glycosylation. The protein bears striking regions of homology with other known lipases and contains peptide sequences that have been implicated in lipid binding. The homologous mRNA is present in liver tissue but no detectable mRNA is observed in the adrenal gland, despite the reported presence of hepatic lipase in both the liver and the adrenal gland. No mRNA was seen in any of a variety of other tissues.Hepatic lipase, localized primarily on the sinusoidal surfaces of the liver, functions in the metabolism of circulating lipoproteins (1). Hepatic lipase activity has also been detected in several extrahepatic tissues, including adrenal gland and ovary (2-4). The presumed function of the enzyme is the hydrolysis of triglycerides in intermediate density lipoproteins (IDL) and of phospholipids in high density lipoproteins (HDL2) (5). The capacity ofpurified hepatic lipase to catalyze hydrolysis of phospholipids and mono-, di-, and triglycerides (6, 7) is consistent with the putative function. The action of hepatic lipase on HDL2 is presumed to result in the production of HDL3. Also, hepatic lipase may participate in the clearance of circulating very low-density lipoproteins (8) and chylomicron remnants (9).Hepatic lipase from rat liver has been purified to homogeneity (7, 10). The enzyme has an apparent molecular weight of53,000 (7,11) cDNA Screening and Analysis. Partial amino acid sequences were determined from the digestion of purified hepatic lipase with subtilisin (11). A single 42-base oligonucleotide probe was constructed on the basis of a 14 amino acid sequence ( Fig. 1) and codon usage tables for mammalian genes (13). In addition to codon usage assumption, G-T base pairing was allowed in designing the probe. A total of 9 x 105 plaques were screened with the end-labeled 42-base oligonucleotide probe. Plaque replicas on nitrocellulose filters were made by the method of Benton and Davis (14). The filters were baked at 80'C for 2 hr and incubated for 3 hr at 370C in 30% (vol/vol) formamide/900 mM NaCl/90 mM trisodium citrate/5 x concentrated Denhardt's solution/50 mM sodium phosphate, pH 6.5, containing salmon sperm DNA at 100 pkg/ml, in a total volume of 200 ml. The 32P-labeled probe (2 x 108 cpm/Ag) was hybridized to the filters for 17 hr at 370C in 200 ml of the same solution. The filters were washed twice at room temperature in 500 ml of 150 mM NaCl/15 mM trisodium citrate/0.1% NaDodSO4 for 30 min per wash, and then six times at 370C in 300 ml of the same solution for 30 min per wash. The filters were exposed to Du Pont Cronex 4 film with Du Pont Hi-Plus intensifying screens at -70'C for 20 hr. DNA from clones t...

show abstract

mentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cloning of rat hepatic lipase cDNA: evidence for a lipase gene family.

Komaromy¹,

Schotz²

1987

Proc. Natl. Acad. Sci. U.S.A.

145

View full text Add to dashboard Cite

show abstract

“…In that ApoE has been implicated as a possible LPL inhibitor (8), its correlation with LPL inhibitory activity may have been masked by the more pronounced correlation between ApoC-III and the LPL activity (5,6). However, additional studies are required to provide direct evidence for a physiologic role of ApoE in modulating LPL activity.…”

Section: Discussionmentioning

confidence: 99%

“…been numerous studies investigating the effect of LPL levels on this process. However, the possible role of apolipoproteins other than apolipoprotein C-II in modulating the LPL activity and controlling the flux of TGs through the lipid transport system has received limited attention, although several investigators have shown that some apolipoproteins inhibit LPL activity (5)(6)(7)(8)(9)(10).…”

Section: Introductionmentioning

confidence: 99%

Modulation of lipoprotein lipase activity by apolipoproteins. Effect of apolipoprotein C-III.

Wang¹,

McConathy²,

Kloer³

et al. 1985

J. Clin. Invest.

412

255

View full text Add to dashboard Cite

From a total of 22 hypertriglyceridemic subjects tested, 14 subjects were selected on the basis of normal postheparin plasma lipoprotein lipase (LPL) levels and the presence of LPL inhibitory activity in their fasting plasma. The inhibitory activity was detected in both the lipoprotein fraction (d < 1.25 g/ml) and the lipo~protein-deficient fraction (d > 1.25 g/ml).Correlational analyses of LPL inhibitory activity and apolipoprotein levels present in the lipoprotein fraction (d < 1.25 g/ml)indicated that only apolipoprotein C-III (ApoC-III) was significantly correlated (r = 0.602, P < 0.05) with the inhibition activity of the lipoprotein fraction. Furthermore, it was found that LPL-inhibitory activities of the plasma lipoprotein fraction and lipoprotein-deficient fraction were also correlated (r = 0.745, P < 0.005), though the activity in the lipoprotein-deficient plasma was not related to the ApoC-III or apolipoprotein E levels. Additional correlational analyses indicated that the LPL levels in the postheparin plasma of these subjects were inversely related to the levels of plasma apolipoproteins C-II, C-III, and E. To explain some of these observations, we directly examined the in vitro effect of ApoC-III on LPL activity. The addition of ApoC-III-2 resulted in a decreased rate of lipolysis of human' very low density lipoproteins by LPL. Kinetic analyses indicated that ApoC-III-2 was a noncompetitive inhibitor of LPL suggesting a direct interaction of the inhibitor with LPL. Results of these studies suggest that ApoCIII may represent a physiologic modulator of LPL activity levels and that the incidence of LPL inhibitory activity in the plasma of hypertriglyceridemic subjects is more common than previously recognized.

show abstract

Lipoproteins and Lipoprotein Lipase

Hamosh

1985

Comprehensive Physiology

View full text Add to dashboard Cite

The sections in this article are: History Lipoproteins Chylomicrons Very‐Low‐Density Lipoproteins Low‐Density Lipoproteins High‐Density Lipoproteins Lipoprotein Lipase History of Lipoprotein Lipase Distribution of Lipoprotein Lipase Regulation of Lipoprotein Lipase Activity Ontogeny of Lipoprotein Lipase Characteristics of Lipoprotein Lipase Mechanisms of Hydrolysis of Circulating Triglycerides Characteristics of Lipolytic Activity of Lipoprotein Lipase Lipoprotein Lipase in Lung Tissue Distribution and Regulation of Activity Lung Lipoprotein Lipase in Disease Origin Functions

show abstract

Rat heart lipoprotein lipase

Cited by 44 publications

References 19 publications

Cloning of rat hepatic lipase cDNA: evidence for a lipase gene family.

Cloning of rat hepatic lipase cDNA: evidence for a lipase gene family.

Modulation of lipoprotein lipase activity by apolipoproteins. Effect of apolipoprotein C-III.

Lipoproteins and Lipoprotein Lipase

Contact Info

Product

Resources

About