SEARCH · Search PubMed

Results for “LIPASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources

PubMed2001

Race differences in the response of postheparin plasma lipoprotein lipase and hepatic lipase activities to endurance exercise training in men: results from the HERITAGE Family Study.

Endurance exercise training is known to produce favorable changes in the metabolic profile including reduced plasma triglyceride (TG) and increased high-density lipoprotein (HDL) cholesterol concentrations. These metabolic improvements are likely to contribute to the reduced coronary heart disease (CHD) risk often observed in physically active individuals. However, the physiological mechanisms responsible for such improvements in TG and HDL cholesterol concentrations with endurance exercise are not fully understood. The effect of a 20-week endurance exercise training program on plasma lipoproteins as well as on post-heparin plasma lipoprotein lipase (PH-LPL) and hepatic lipase (PH-HL) activities were therefore examined in a sample of 200 White and 69 Black men who were part of the HERITAGE Family Study. As expected, there were decreases in adiposity and in abdominal fat accumulation following training in both White and Black men. We also found that exercise training was associated with decreases in plasma cholesterol, TG and apolipoprotein B levels, as well as with an increase in HDL cholesterol concentrations in White men. In contrast, Black men showed an increase only in HDL(2) cholesterol over the 20-week period. Higher PH-LPL and lower PH-HL activities were noted in both ethnic groups at follow-up. Whereas in White men improvement of the lipoprotein-lipid profile was related to increased PH-LPL activity, no association between PH-LPL (or PH-HL) and lipoprotein-lipid variables was observed in Black men. Results of the present study suggest that in Whites, the increase in PH-LPL activity in response to endurance exercise training is associated with a better lipoprotein-lipid profile, therefore reducing CHD risk. However, the generally better metabolic profile of Black individuals may minimize further improvement of lipoprotein-lipid concentrations by exercise training.

Adipose Tissue↗

PubMed2003

Interaction effect of Serine447Stop variant of the lipoprotein lipase gene and C-514T variant of the hepatic lipase gene on serum triglyceride levels in young adults: the Bogalusa Heart Study.

The opposing effects of lipoprotein lipase (LPL) Serin447Stop (S447X) polymorphism and hepatic lipase (HL) C-514T polymorphism on serum triglyceride (TG) levels have been known. However, little is known about the interaction effect of these 2 functional gene variants on serum triglyceride levels. This aspect was examined in a community-based sample of 902 whites and 389 blacks aged 18 to 41 years, using a repeated measures analysis in a mixed model. The frequency of the LPL X447 allele was higher in whites than blacks (16% v 11%, P <.05); whereas the frequency of HL T-514 allele was higher in blacks than whites (77% v 40%, P <.001). The combined genotype distribution was also different between whites and blacks (P <.001). Although the frequency of carriers of both variants was similar in whites and blacks (7% v 8%), more whites carried the LPL X447 allele only (9% v 3%), and more blacks carried the HL T-514 allele only (70% v 33%). Mean levels of TG adjusted for age, sex, and body mass index (BMI) in carriers versus noncarriers of the LPL X447 allele were lower by 13.5% (P <.0001) in whites, 15.8% (P <.01) in blacks and 16.0% (P <.0001) in the total sample. No such phenotypic effect was noted with respect to HL T-514 allele either in blacks or whites, although the mean level in carriers was marginally (P =.08) higher in the total sample. The interaction effect of LPL and HL variants on TG levels was significant in the total sample (P =.016) and marginal in whites (P =.079). In the total sample, the decrease of TG in carriers versus noncarriers of the LPL X447 was 1.8-fold greater in carriers versus noncarriers of the HL T-514 allele (13.6 mg/dL v 7.4 mg/dL, P =.016). Whites tended to show a similar trend (16.8 mg/dL v 6.1 mg/dL, P =.079). Blacks also showed a similar, but nonsignificant, trend (10.4 mg/dL v 8.6 mg/dL, P =.45). These results by showing modulation of association between S447X variant of the LPL gene and serum TG by C-514T variant of the HL gene underscore the importance of gene-gene interactions in the assessment of genetic effects on complex traits.

Adult↗

PubMed1999

The ABC-exporter genes involved in the lipase secretion are clustered with the genes for lipase, alkaline protease, and serine protease homologues in Pseudomonas fluorescens no. 33.

In Pseudomonas fluorescens no. 33, the lipase gene is clustered with the genes for alkaline protease, AprDEF exporter, and two homologue proteins of Serratia serine proteases (pspA and pspB). Secretion of the lipase and alkaline protease through AprDEF was shown in the Escherichia coli cells. Interestingly, the E. coli cells carrying the pspA gene secreted PspA to the media AprDEF-independently.

ATP-Binding Cassette Transporters↗

PubMed1997

Probing the substrate specificity for lipases. II. Kinetic and modeling studies on the molecular recognition of 2-arylpropionic esters by Candida rugosa and Rhizomucor miehei lipases.

Racemic arylpropionic esters 1-3, precursors of therapeutically important non-steroidal antiinflammatory drugs, were subjected to hydrolyses in the presence of either Candida rugosa or Rhizomucor miehei crude lipases. The hydrolyses of 1 and 2 proved to be highly enantioselective, whereas 3 was not transformed at all. Both the substrate specificity and the enantioselectivity of these lipases were explained through a molecular modeling study involving docking experiments between 1-3 and the amino acids forming the enzymes active-sites, whose three dimensional structures were obtained from X-ray crystallographic data, followed by extensive conformational analysis on their computer-generated complexes. The results of this study also account for the high enantioselective and good yielding hydrolysis of 3 (as the corresponding 2-chloroethyl ester) catalyzed by CRL pretreated with 2-propanol, recently reported in the literature, and lead to admit that such a treatment may operate very deep conformational changes on the amino acids of the enzyme active-site.

Binding Sites↗

PubMed2000

Difference in substrate specificity between human and mouse lysosomal acid lipase: low affinity for cholesteryl ester in mouse lysosomal acid lipase.

Lysosomal acid lipase (LAL) is essential for the intracellular degradation of cholesteryl esters (CE) and triacylglycerols (TG) that are delivered to lysosomes by low density lipoprotein (LDL) receptor mediated endocytosis. We have analysed the difference in the catalytic properties and substrate specificity of human and mouse LALs. LAL activities were measured in human and mouse fibroblasts and in HeLa cells transiently expressing wild-type or site-directed mutant LALs of the two species using the T7 vaccinia system. Cholesteryl esterase and triacylglycerol lipase activities were determined in cellular homogenates with a phospholipid/detergent vesicle assay, an assay frequently used to diagnose human LAL deficiency syndromes, and with LDL particles, a more physiological substrate. Characterisation of human and mouse LAL using these two assays demonstrated marked differences in their TG and CE hydrolysing activities. Compared to human LAL mouse LAL showed a much lower cholesteryl esterase activity in both assays used. The difference was more pronounced in the vesicle assay. The lower cholesteryl esterase activity of mouse LAL did not affect the LDL-CE degradation in intact fibroblasts. The analysis of site-directed mutants suggests a role of the non-conserved cysteine residue at position 240 in cholesteryl esterase activity in human LAL. Our results show a significant difference between human and mouse LAL in their specificity toward cholesteryl esters. The low cholesteryl esterase activity does not result in reduced LDL-cholesterol ester degradation in mouse fibroblasts in situ. In addition, this work emphasises the importance of the physical state of substrates in studies of the specificity and properties of lipolytic enzymes.

Animals↗

PubMed1998

Substrate specificity of Staphylococcus hyicus lipase and Staphylococcus aureus lipase as studied by in vivo chimeragenesis.

Staphylococcus hyicus lipase (SHL) and Staphylococcus aureus lipase (SAL) are highly homologous enzymes, yet they show remarkable differences in their biochemical characteristics. SHL displays a high phospholipase activity, hydrolyses neutral lipids, and has no chain length preference, whereas SAL only degrades short-chain fatty acid esters. To identify the regions in the primary sequence of SHL responsible for phospholipase activity and chain length selectivity, a set of histidine-tagged SAL/SHL chimeras was generated by in vivo recombination in Escherichia coli. Several classes of chimeric enzymes were identified on the basis of restriction site analysis. All chimeras were well-expressed as active enzymes. They were characterized for their specific activities on both phospholipids and p-nitrophenyl esters of various chain lengths. Phospholipase activity appeared to be determined by three regions, all located in the C-terminal domain of SHL. Testing of the enzymatic activity of the chimeras toward p-nitrophenyl esters showed that chain length selectivity is defined by elements within the region of residues 180-253. Moreover, also residues along the stretch 275-358 contribute to the binding of acyl chains. Interestingly, several chimeras were even more active than the parent enzymes on long-chain p-nitrophenyl esters.

Amino Acid Sequence↗

PubMedDate not supplied

Different properties of the lipases contained in porcine pancreatic lipase extracts as enantioselective biocatalysts.

The porcine pancreatic lipase (PPL) extracts contain a mixture of several lipases. Their fractioning was performed by sequential adsorption via interfacial activation on supports with different hydrophobicity. A protein of 25 KDa was preferentially adsorbed on octyl-Sepharose, another protein of 33 kDa was mainly adsorbed on octadecyl-Sepabeads support, and the PPL was mainly adsorbed on the support bearing phenyl groups. The different immobilized preparations showed different properties and different response due to change in the experimental conditions. Thus, in the hydrolysis of (+/-)-2-hydroxy-4-phenylbutyric acid ethyl ester [(+/-)-1] to produce the corresponding acid [2], the octyl-25KDa preparation showed the best enantioselectivity (E) value (E = 7) at pH 5 and 25 degrees C, whereas the phenyl-PPL was the most enantioselective (E = 10) at pH 5, 4 degrees C, and 10% dioxane. Using different preparations at different pHs it was possible to resolve (+/-)-2-O-butyryl-2-phenylacetic acid [(+/-)-3] with a high E value (E > 100); for example, with octadecyl-33 KDa enzyme at pH 8.

Animals↗

PubMedDate not supplied

Messenger RNAs encoding lipoprotein lipase, fatty acid synthase and hormone-sensitive lipase in the adipose tissue of underfed-refed ewes and cows.

The mechanisms involved in the nutritional regulation of genes encoding lipogenic (lipoprotein lipase (LPL) and fatty acid synthase (FAS)) and lipolytic (hormone-sensitive lipase (HSL)) enzymes were investigated by comparing the levels of the corresponding mRNAs in the adipose tissue (AT) of underfed or underfed-refed ewes and cows. Refeeding sharply increased LPL and FAS activities (19-25- and 6-8-fold, respectively) and moderately increased (2-4 fold) the activities of glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME) and glycerol-3-phosphate dehydrogenase (G3PDH). Northern blot analysis revealed three LPL transcripts and a single FAS transcript in cow and ewe AT. A single HSL mRNA was detected in cow AT and two transcripts in ewe AT. Refeeding sharply increased LPL and FAS mRNA levels, while restriction slightly increased (cows) or had no effect (ewes) on the HSL mRNA levels. This suggests that nutritional factors regulate sharply the expression of LPL and FAS genes by pretranslational mechanisms, but less clearly that of HSL gene.

Adipose Tissue↗

PubMed2000

Regulation of lipoprotein lipase and hormone-sensitive lipase activity and gene expression in adipose and muscle tissue by growth hormone treatment during weight loss in obese patients.

It is well known that growth hormone (GH) treatment reduces fat mass (FM), which presumably is mediated through stimulation of triglyceride breakdown and inhibition of adipose tissue lipoprotein lipase activity (AT-LPL). However, it is unknown which of the 2 GH-regulated pathways are of most importance for the reduction in FM. We investigated the effect of weight loss together with GH treatment on the activity and gene expression of LPL and hormone-sensitive lipase (HSL) in AT and muscle tissue. A very-low-calorie diet ([VLCD] 740 kcal/d) was given to 18 obese women (body mass index [BMI] > 35 kg/m2) and half of them were treated with GH (0.04 IU/kg) for 4 weeks in a randomized double-blind placebo-controlled study. Subcutaneous fat and muscle biopsies were taken before and after 4 weeks. Weight loss after 4 weeks was similar in the 2 groups, with a reduction of 4.5% (placebo) and 4.6% (GH) and a reduction of FM by 7.4% and 9.0% ([NS] nonsignificant). The weight loss resulted in a small and NS reduction of AT-LPL activity by 20% +/- 12% in the placebo group, but in the GH group, AT-LPL was significantly reduced by 65% +/- 8% (P < .01). Muscle LPL (M-LPL) activity was not affected by the weight loss alone, but a significant reduction was observed in the GH group (20.4% +/- 10%, P < .05). AT-HSL activity was significantly enhanced after weight loss, but GH had no additional effect on this minor increment. This is in accordance with the finding that the increment in free fatty acid (FFA) after weight loss was similar in the 2 groups. GH treatment was associated with a significant reduction of high-density lipoprotein (HDL) cholesterol (P < .05). In conclusion, GH significantly inhibited AT-LPL activity but had no additional effect on the hypocaloric-induced loss of FM, indicating that under such circumstances, AT-LPL does not directly regulate adipose tissue mass. GH was not found to have opposite effects on the activity of LPL in adipose tissue and muscle, since GH treatment reduced them both (by 65% and 20%, respectively). The VLCD-induced weight loss was associated with a minor enhanced activity of AT-HSL with no independent effect of GH. Thus, concerning body weight, FM, and lipolytic activity, treatment with GH offers no extra benefits during a VLCD for 4 weeks.

Adipose Tissue↗

PubMed2003

17Beta-estradiol and anti-estrogen ICI:compound 182,780 regulate expression of lipoprotein lipase and hormone-sensitive lipase in isolated subcutaneous abdominal adipocytes.

We sought to investigate the influence of 17beta-estradiol (E(2)) on key enzymes of lipogenesis and lipolysis in subcutaneous (SC) abdominal adipocytes isolated from women. In addition, we wished to determine the influence of an anti-estrogen, ICI:compound 182,780 (anti-E), known to act via the estrogen receptor (ER), alone and in combination with E(2). Adipose tissue was obtained from 17 women undergoing elective surgery, with a mean age of 47 years (range, 34 to 62), mean weight of 65.4 kg (range, 58.1 to 75.0), and mean body mass index (BMI) of 25 kg/m(2) (range, 22 to 27). Isolated adipocytes were treated with varying doses of E(2), anti-E, or E(2) in combination with anti-E 10(-8) mol/L for 48 hours. Following treatment, proteins were extracted and the effects on lipogenesis and lipolysis were assessed, using Western blotting to determine the relative expression of the key enzymes of these processes, lipoprotein lipase (LPL; 56 kd), and hormone-sensitive lipase (HSL; 84 kd), respectively. Glycerol release into the medium was also measured as an index of lipolytic activity. The protein expression studies demonstrated that E(2) altered expression of LPL relative to control, with the highest dose significantly reducing LPL expression and the lower doses significantly increasing LPL expression (mean protein expression relative to control +/- SE): E(2) 10(-12) mol/L, 1.79 +/- 0.16 (P <.001); E(2) 10(-7) mol/L, 0.56 +/- 0.08 (P <.05). In contrast, HSL expression was increased relative to control at the higher doses of E(2) but was not significantly altered relative to control at the lower doses: E(2) 10(-12) mol/L, 1.02 +/- 0.14 (P >.05); E(2) 10(-7) mol/L, 1.55 +/- 0.17 (P <.01). Anti-E 10(-8) mol/L alone reduced LPL protein expression relative to control (P <.05) and increased HSL protein expression relative to control (P >.05). In combination with E(2) 10(-7) mol/L, anti-E 10(-8) mol/L did not abrogate the inhibitory effect on LPL expression relative to control (P <.05). Furthermore, E(2) 10(-7) mol/Lin combination with anti-E 10(-8) mol/L, displayed a stimulatory effect on HSL expression relative to control (P <.01). Glycerol release studies following the higher doses of E(2), and also following E(2) 10(-7) mol/L in combination with anti-E 10(-8) mol/L, provided support for the HSL protein expression studies. We conclude that the highest concentration of E(2) (10(-7) mol/L) significantly reduced LPL expression relative to control, while the lower concentrations significantly increased LPL expression relative to control. The highest concentration of E(2) also significantly increased both HSL expression and glycerol release relative to control. The effects of anti-E suggest that the in vitro effects of E(2) on lipogenesis and lipolysis occur, at least in part, through a receptor-mediated pathway. In addition, as recently observed in other tissues, ICI:compound 182,780 does not appear to behave as a pure anti-estrogen in isolated human adipocytes.

Abdomen↗

PubMed2000

Crystal structure of pseudomonas aeruginosa lipase in the open conformation. The prototype for family I.1 of bacterial lipases.

The x-ray structure of the lipase from Pseudomonas aeruginosa PAO1 has been determined at 2.54 A resolution. It is the first structure of a member of homology family I.1 of bacterial lipases. The structure shows a variant of the alpha/beta hydrolase fold, with Ser(82), Asp(229), and His(251) as the catalytic triad residues. Compared with the "canonical" alpha/beta hydrolase fold, the first two beta-strands and one alpha-helix (alphaE) are not present. The absence of helix alphaE allows the formation of a stabilizing intramolecular disulfide bridge. The loop containing His(251) is stabilized by an octahedrally coordinated calcium ion. On top of the active site a lid subdomain is in an open conformation, making the catalytic cleft accessible from the solvent region. A triacylglycerol analogue is covalently bound to Ser(82) in the active site, demonstrating the position of the oxyanion hole and of the three pockets that accommodate the sn-1, sn-2, and sn-3 fatty acid chains. The inhibited enzyme can be thought to mimic the structure of the tetrahedral intermediate that occurs during the acylation step of the reaction. Analysis of the binding mode of the inhibitor suggests that the size of the acyl pocket and the size and interactions of the sn-2 binding pocket are the predominant determinants of the regio- and enantio-preference of the enzyme.

Amino Acid Sequence↗

PubMed2002

Hormone-sensitive lipase deficiency in mice changes the plasma lipid profile by affecting the tissue-specific expression pattern of lipoprotein lipase in adipose tissue and muscle.

Hormone-sensitive lipase (HSL) is believed to play an important role in the mobilization of fatty acids from triglycerides (TG), diglycerides, and cholesteryl esters in various tissues. Because HSL-mediated lipolysis of TG in adipose tissue (AT) directly feeds non-esterified fatty acids (NEFA) into the vascular system, the enzyme is expected to affect many metabolic processes including the metabolism of plasma lipids and lipoproteins. In the present study we examined these metabolic changes in induced mutant mouse lines that lack HSL expression (HSL-ko mice). During fasting, when HSL is normally strongly induced in AT, HSL-ko animals exhibited markedly decreased plasma concentrations of NEFA (-40%) and TG (-63%), whereas total cholesterol and HDL cholesterol levels were increased (+34%). Except for the increased HDL cholesterol concentrations, these differences were not observed in fed animals, in which HSL activity is generally low. Decreased plasma TG levels in fasted HSL-ko mice were mainly caused by decreased hepatic very low density lipid lipoprotein (VLDL) synthesis as a result of decreased NEFA transport from the periphery to the liver. Reduced NEFA transport was also indicated by a depletion of hepatic TG stores (-90%) and strongly decreased ketone body concentrations in plasma (-80%). Decreased plasma NEFA and TG levels in fasted HSL-ko mice were associated with increased fractional catabolic rates of VLDL-TG and an induction of the tissue-specific lipoprotein lipase (LPL) activity in cardiac muscle, skeletal muscle, and white AT. In brown AT, LPL activity was decreased. Both increased VLDL fractional catabolic rates and increased LPL activity in muscle were unable to provide the heart with sufficient NEFA, which led to decreased tissue TG levels in cardiac muscle. Our results demonstrate that HSL deficiency markedly affects the metabolism of TG-rich lipoproteins by the coordinate down-regulation of VLDL synthesis and up-regulation of LPL in muscle and white adipose tissue. These changes result in an "anti-atherogenic" lipoprotein profile.

Adipose Tissue↗

PubMed2002

Down-regulation of adipose tissue lipoprotein lipase during fasting requires that a gene, separate from the lipase gene, is switched on.

During short term fasting, lipoprotein lipase (LPL) activity in rat adipose tissue is rapidly down-regulated. This down-regulation occurs on a posttranslational level; it is not accompanied by changes in LPL mRNA or protein levels. The LPL activity can be restored within 4 h by refeeding. Previously, we showed that during fasting there is a shift in the distribution of lipase protein toward an inactive form with low heparin affinity. To study the nature of the regulatory mechanism, we determined the in vivo turnover of LPL activity, protein mass, and mRNA in rat adipose tissue. When protein synthesis was inhibited with cycloheximide, LPL activity and protein mass decreased rapidly and in parallel with half-lives of around 2 h, and the effect of refeeding was blocked. This indicates that maintaining high levels of LPL activity requires continuous synthesis of new enzyme protein. When transcription was inhibited by actinomycin, LPL mRNA decreased with half-lives of 13.3 and 16.8 h in the fed and fasted states, respectively, demonstrating slow turnover of the LPL transcript. Surprisingly, when actinomycin was given to fed rats, LPL activity was not down-regulated during fasting, indicating that actinomycin interferes with the transcription of a gene that blocks the activation of newly synthesized LPL protein. When actinomycin was given to fasted rats, LPL activity increased 4-fold within 6 h, even in the absence of refeeding. The same effect was seen with alpha-amanitin, another inhibitor of transcription. The response to actinomycin was much less pronounced in aging rats, which are obese and insulin-resistant. These data suggest a default state where LPL protein is synthesized on a relatively stable mRNA and is processed into its active form. During fasting, a gene is switched on whose product prevents the enzyme from becoming active even though synthesis of LPL protein continues unabated.

Adipose Tissue↗

PubMed1978

The influence of dietary fat and meal frequency on lipoprotein lipase and hormone-sensitive lipase in rat adipose tissue.

Activities of NaCl-inactivated lipoprotein lipase (LPL) and protamine-resistant hormone-sensitive lipase (HSL) in adipose tissue, accumulation of carcass fat, and serum triglycerides (TG) were determined in meal-fed (MF) and ad libitum-fed (AD) rats. At each feeding frequency, diets provided total fat as 15 or 30% of calories and polyunsaturated fatty acids (PUFA) as 2.5 or 11% of calories. The average energy intake of MF rats was 67% that of AD rats. Total weight gained by MF rats was only 60% that of the AD rats. Significantly greater activities of LPL, HSL, and LPL:HSL in adipose of MF rats suggested a greater capacity for fat accumulation which was not realized at the limited energy intake. In AD rats, the percentage of body fat was significantly correlated with LPL:HSL and with serum TG, suggesting that the relative enzyme activities and fat deposition may be influenced by the concentration of circulating TG. Mean body fat of rats receiving the 30% fat diet was significantly greater than that of rats fed 15% fat. Both serum TG and adipose LPL activity were significantly reduced when the diet contained high levels of PUFA.

Adipose Tissue↗

PubMed1989

Human gastric lipase. The N-terminal tetrapeptide is essential for lipid binding and lipase activity.

Human gastric lipase subjected to limited tryptic proteolysis lost its ability to hydrolyze emulsified long-chain triacylglycerol. Activity against a water-soluble substrate was however retained, indicating that proteolysis did not affect the active site. Sequence analysis revealed that trypsin specifically cleaved the linkage between lysine-4 and leucine-5. This cleavage rendered the enzyme unable to bind to emulsified triacylglycerol particles, e.g. human milk fat globules. We suggest that the N-terminal tetrapeptide, in particular lysine-4, is essential for the binding of human gastric lipase to lipid/water interfaces, and hence, for its physiological function.

Amino Acid Sequence↗

PubMed1986

Lysogenic conversion of staphylococcal lipase is caused by insertion of the bacteriophage L54a genome into the lipase structural gene.

Staphylococcus aureus PS54 manifests no lipase (geh) activity. This is due to the insertion of bacteriophage L54a DNA into the geh structural gene. The nucleotide sequence of this 2,968-base-pair DNA fragment was determined. Lipase deduced from the nucleotide sequence is a polypeptide of 690 amino acids which extends from nucleotide 706 to 2776.

Amino Acid Sequence↗

PubMed1991

Cloning, sequence, and expression of a lipase gene from Pseudomonas cepacia: lipase production in heterologous hosts requires two Pseudomonas genes.

The lipA gene encoding an extracellular lipase from Pseudomonas cepacia was cloned and sequenced. Downstream from the lipase gene an open reading frame was identified, and the corresponding gene was named limA. lipA was well expressed only in the presence of limA. limA exerts its effect both in cis and in trans and therefore produces a diffusible gene product, presumably a protein of 344 amino acids. Replacement of the lipA expression signals (promoter, ribosome-binding site, and signal peptide-coding sequences) by heterologous signals from gram-positive bacteria still resulted in limA-dependent lipA expression in Escherichia coli, Bacillus subtilis, and Streptomyces lividans.

Amino Acid Sequence↗

PubMed1994

Lipoprotein lipase and hormone-sensitive lipase activity and mRNA in rat adipose tissue during pregnancy.

To investigate the factors controlling maternal depot fat accumulation during early pregnancy and net decrease during late pregnancy, the activity and mRNA expression of adipose tissue lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) were related to several other lipid metabolic parameters. Virgin control rats, pregnant rats (at days 12, 15, 19, and 21), and lactating rats (at days 5 and 10 postpartum) were studied. In adipose lumbar tissue of late pregnant rats, LPL activity decreased to about one-third that of the virgin control animals, with < 10% of initial LPL mRNA expressed as determined by Northern blots. HSL activity increased maximally 1.5-fold with a fourfold increase of HSL expression at days 12-15 of pregnancy and decreased to control levels after parturition. The HSL-to-LPL mRNA and activity ratios were enhanced from days 15 and 19 of pregnancy, respectively, and remained so even during lactation, mainly because of the marked lowering of the LPL values. This enhancement coincided with increments in plasma free fatty acids and glycerol levels indicating an increased depot fat breakdown. These results give no indication of an involvement of LPL and HSL gene expression changes in the accumulation of maternal depot during early pregnancy. In contrast, such changes could be responsible for the net breakdown of this fat depot during late gestation. Thus, during this physiological state, long-term (e.g., transcriptional) regulation of LPL and HSL gene expression could be an important mechanism for the control of adipose tissue mass breakdown during late gestation.

Adipose Tissue↗