Gibberellin hormone signal perception: down-regulating DELLA repressors of plant growth and development

Science.gov (United States)

The gibberellin (GA) hormone signal is perceived by a receptor with homology to hormone sensitive lipases, GID1 (GA-INSENSITIVE DWARF1). This leads to GA-stimulated responses including stem elongation, seed germination, and the transition to flowering. GA-binding enables GID1 to interact with and ...

Growth hormone-mediated breakdown of body fat

DEFF Research Database (Denmark)

Johansen, T.; Malmlöf, K.; Richelsen, Bjørn

2003-01-01

regimen. Twelve-month-old rats fed first a high-fat diet or a low-fat diet for 14 weeks were injected with saline or growth hormone (4 mg/kg/d) for four days or three weeks in different combinations with either high- or low-fat diets. In adipose tissue, growth hormone generally inhibited lipoprotein...... lipase and also attenuated the inhibiting effect of insulin on hormone-sensitive lipase activity. Growth hormone treatment combined with restricted high-fat feeding reduced the activity of both lipases in adipose tissue and stimulated hormone-sensitive lipase in muscle. Generally, plasma levels of free...... fatty acids, glycerol and cholesterol were reduced by growth hormone, and in combination with restricted high-fat feeding, triglyceride levels improved too. We conclude that growth hormone inhibits lipid storage in adipose tissue by reducing both lipoprotein lipase activity and insulin's inhibitory...

Contractions activate hormone-sensitive lipase in rat muscle by protein kinase C and mitogen-activated protein kinase

DEFF Research Database (Denmark)

Donsmark, Morten; Langfort, Jozef; Holm, Cecilia

2003-01-01

and contractions. Adrenaline acts via cAMP-dependent protein kinase (PKA). The signalling mediating the effect of contractions is unknown and was explored in this study. Incubated soleus muscles from 70 g male rats were electrically stimulated to perform repeated tetanic contractions for 5 min. The contraction......Intramuscular triacylglycerol is an important energy store and is also related to insulin resistance. The mobilization of fatty acids from this pool is probably regulated by hormone-sensitive lipase (HSL), which has recently been shown to exist in muscle and to be activated by both adrenaline......-induced activation of HSL was abolished by the protein kinase C (PKC) inhibitors bisindolylmaleimide I and calphostin C and reduced 50% by the mitogen-activated protein kinase kinase (MEK) inhibitor U0126, which also completely blocked extracellular signal-regulated kinase (ERK) 1 and 2 phosphorylation. None...

Protein phosphorylation in isolated human adipocytes - Adrenergic control of the phosphorylation of hormone-sensitive lipase

International Nuclear Information System (INIS)

Smiley, R.M.; Paul, S.; Browning, M.D.; Leibel, R.L.; Hirsch, J.

1990-01-01

The effect of adrenergic agents on protein phosphorylation in human adipocytes was examined. Freshly isolated human fat cells were incubated with 32 PO 4 in order to label intracellular ATP, then treated with a variety of adrenergic and other pharmacologic agents. Treatment with the β-adrenergic agonist isoproterenol led to a significant increase in phosphate content of at least five protein bands (M r 52, 53, 63, 67, 84 kDa). The increase in phosphorylation was partially inhibited by the α-2 agonist clonidine. Epinephrine, a combined α and β agonist, was less effective at increasing phosphate content of the proteins than was isoproterenol. Neither insulin nor the α-1 agonist phenylephrine had any discernible effect on the pattern of protein phosphorylation. The 84 kDa phosphorylated peptide band appears to contain hormone-sensitive lipase, a key enzyme in the lipolytic pathway which is activated by phosphorylation. These results are somewhat different than previously reported results for rat adipocytes, and represent the first report of overall pattern and adrenergic modulation of protein phosphorylation in human adipocytes

Rat liver contains a limited number of binding sites for hepatic lipase

NARCIS (Netherlands)

G.C. Schoonderwoerd (Kees); A.J.M. Verhoeven (Adrie); H. Jansen (Hans)

1994-01-01

textabstractThe binding of hepatic lipase to rat liver was studied in an ex vivo perfusion model. The livers were perfused with media containing partially purified rat hepatic lipase or bovine milk lipoprotein lipase. The activity of the enzymes was determined in the

Effect of weight reduction on insulin sensitivity, sex hormone-binding globulin, sex hormones and gonadotrophins in obese children

DEFF Research Database (Denmark)

Birkebaek, N H; Lange, Aksel; Holland-Fischer, P

2010-01-01

Obesity in men is associated with reduced insulin sensitivity and hypoandrogenism, while obesity in women is associated with reduced insulin sensitivity and hyperandrogenism. In children, the effect of obesity and weight reduction on the hypothalamo-pituitary-gonadal axis is rarely investigated. ....... The aim of the present study was to investigate the effect of weight reduction in obese Caucasian children on insulin sensitivity, sex hormone-binding globulin (SHBG), DHEAS and the hypothalamo-pituitary-gonadal axis.......Obesity in men is associated with reduced insulin sensitivity and hypoandrogenism, while obesity in women is associated with reduced insulin sensitivity and hyperandrogenism. In children, the effect of obesity and weight reduction on the hypothalamo-pituitary-gonadal axis is rarely investigated...

Adipose tissue deficiency of hormone-sensitive lipase causes fatty liver in mice.

Science.gov (United States)

Xia, Bo; Cai, Guo He; Yang, Hao; Wang, Shu Pei; Mitchell, Grant A; Wu, Jiang Wei

2017-12-01

Fatty liver is a major health problem worldwide. People with hereditary deficiency of hormone-sensitive lipase (HSL) are reported to develop fatty liver. In this study, systemic and tissue-specific HSL-deficient mice were used as models to explore the underlying mechanism of this association. We found that systemic HSL deficient mice developed fatty liver in an age-dependent fashion between 3 and 8 months of age. To further explore the mechanism of fatty liver in HSL deficiency, liver-specific HSL knockout mice were created. Surprisingly, liver HSL deficiency did not influence liver fat content, suggesting that fatty liver in HSL deficiency is not liver autonomous. Given the importance of adipose tissue in systemic triglyceride metabolism, we created adipose-specific HSL knockout mice and found that adipose HSL deficiency, to a similar extent as systemic HSL deficiency, causes age-dependent fatty liver in mice. Mechanistic study revealed that deficiency of HSL in adipose tissue caused inflammatory macrophage infiltrates, progressive lipodystrophy, abnormal adipokine secretion and systemic insulin resistance. These changes in adipose tissue were associated with a constellation of changes in liver: low levels of fatty acid oxidation, of very low density lipoprotein secretion and of triglyceride hydrolase activity, each favoring the development of hepatic steatosis. In conclusion, HSL-deficient mice revealed a complex interorgan interaction between adipose tissue and liver: the role of HSL in the liver is minimal but adipose tissue deficiency of HSL can cause age-dependent hepatic steatosis. Adipose tissue is a potential target for treating the hepatic steatosis of HSL deficiency.

SHBG (Sex Hormone Binding Globulin)

Science.gov (United States)

... Links Patient Resources For Health Professionals Subscribe Search Sex Hormone Binding Globulin (SHBG) Send Us Your Feedback ... As Testosterone-estrogen Binding Globulin TeBG Formal Name Sex Hormone Binding Globulin This article was last reviewed ...

Regulation and role of hormone-sensitive lipase in rat skeletal muscle

DEFF Research Database (Denmark)

Donsmark, Morten; Langfort, Jozef; Holm, Cecilia

2004-01-01

the effects of contractions and adrenaline on HSL activity are partially additive. In line with the view that the two stimuli act by different mechanisms, training increases contraction-mediated HSL activation but diminishes adrenaline-mediated HSL activation in muscle. In conclusion, HSL is present...... fibre types, being higher in oxidative fibres than in glycolytic fibres. When analysed under conditions optimal for HSL, neutral lipase activity in muscle can be stimulated by adrenaline as well as by contractions. These increases are abolished by the presence of anti-HSL antibody during analysis....... Moreover, immunoprecipitation with affinity-purified anti-HSL antibody causes similar reductions in muscle HSL protein concentration and in measured neutral lipase responses to contractions. The immunoreactive HSL in muscle is stimulated by adrenaline via beta-adrenergic activation of c...

Essential role of hormone-sensitive lipase (HSL) in the maintenance of lipid storage in Mycobacterium leprae-infected macrophages.

Science.gov (United States)

Tanigawa, Kazunari; Degang, Yang; Kawashima, Akira; Akama, Takeshi; Yoshihara, Aya; Ishido, Yuko; Makino, Masahiko; Ishii, Norihisa; Suzuki, Koichi

2012-05-01

Mycobacterium leprae (M. leprae), the causative agent of leprosy, parasitizes within the foamy or enlarged phagosome of macrophages where rich lipids accumulate. Although the mechanisms for lipid accumulation in the phagosome have been clarified, it is still unclear how such large amounts of lipids escape degradation. To further explore underlying mechanisms involved in lipid catabolism in M. leprae-infected host cells, we examined the expression of hormone-sensitive lipase (HSL), a key enzyme in fatty acid mobilization and lipolysis, in human macrophage THP-1 cells. We found that infection by live M. leprae significantly suppressed HSL expression levels. This suppression was not observed with dead M. leprae or latex beads. Macrophage activation by peptidoglycan (PGN), the ligand for toll-like receptor 2 (TLR2), increased HSL expression; however, live M. leprae suppressed this increase. HSL expression was abolished in the slit-skin smear specimens from patients with lepromatous and borderline leprosy. In addition, the recovery of HSL expression was observed in patients who experienced a lepra reaction, which is a cell-mediated, delayed-type hypersensitivity immune response, or in patients who were successfully treated with multi-drug therapy. These results suggest that M. leprae suppresses lipid degradation through inhibition of HSL expression, and that the monitoring of HSL mRNA levels in slit-skin smear specimens may be a useful indicator of patient prognosis.

Lipase inhibition and hormonal status, body composition and gastrointestinal processing of a liquid high-fat mixed meal in moderately obese subjects.

NARCIS (Netherlands)

Drent, M.L.; Popp-Snijders, C.; Adèr, H.J.; Jansen, J.B.M.J.; van der Veen, E.A.

1995-01-01

DRENT, MADELEINE L, CORRIE POPP‐SNIJDERS, HERMAN J ADER, JAN BMJ JANSEN AND EDUARD A VAN DER VEEN. Lipase inhibition and hormonal status, body composition and gastrointestinal processing of a liquid high‐fat mixed meal in moderately obese subjects. Obes Res. The effect of Orlistat, a lipase

Biochemical and Structural Analysis of Hormone-sensitive Lipase Homolog EstE7: Insight into the Stabilized Dimerization of HSL-Homolog Proteins

International Nuclear Information System (INIS)

Nam, Ki Hyun; Park, Sung Ha; Lee, Won Ho; Hwang, Kwang Yeon

2010-01-01

Hormone sensitive lipase (HSL) plays a major role in energy homeostasis and lipid metabolism. Several crystal structures of HSL-homolog proteins have been identified, which has led to a better understanding of its molecular function. HSLhomolog proteins exit as both monomer and dimer, but the biochemical and structural basis for such oligomeric states has not been successfully elucidated. Therefore, we determined the crystal structure of HSL-homolog protein EstE7 from a metagenome library at 2.2 A resolution and characterized the oligomeric states of EstE7 both structurally and biochemically. EstE7 protein prefers the dimeric state in solution, which is supported by its higher enzymatic activity in the dimeric state. In the crystal form, EstE7 protein shows two-types of dimeric interface. Specifically, dimerization via the external β8-strand occurred through tight association between two pseudosymmetric folds via salt bridges, hydrogen bonds and van der Waals interactions. This dimer formation was similar to that of other HSL-homolog protein structures such as AFEST, BEFA, and EstE1. We anticipate that our results will provide insight into the oligomeric state of HSLhomolog proteins

Hormone-sensitive lipase null mice exhibit signs of impaired insulin sensitivity whereas insulin secretion is intact

DEFF Research Database (Denmark)

Mulder, Hindrik; Sörhede-Winzell, Maria; Contreras, Juan Antonio

2003-01-01

of increased amounts of insulin. Impaired insulin sensitivity was further indicated by retarded glucose disposal during an insulin tolerance test. A euglycemic hyperinsulinemic clamp revealed that hepatic glucose production was insufficiently blocked by insulin in HSL null mice. In vitro, insulin......-stimulated glucose uptake into soleus muscle, and lipogenesis in adipocytes were moderately reduced, suggesting additional sites of insulin resistance. Morphometric analysis of pancreatic islets revealed a doubling of beta-cell mass in HSL null mice, which is consistent with an adaptation to insulin resistance....... Insulin secretion in vitro, examined by perifusion of isolated islets, was not impacted by HSL deficiency. Thus, HSL deficiency results in a moderate impairment of insulin sensitivity in multiple target tissues of the hormone but is compensated by hyperinsulinemia....

Fatty Acid Signaling: The New Function of Intracellular Lipases

Directory of Open Access Journals (Sweden)

Zuzana Papackova

2015-02-01

Full Text Available Until recently, intracellular triacylglycerols (TAG stored in the form of cytoplasmic lipid droplets have been considered to be only passive “energy conserves”. Nevertheless, degradation of TAG gives rise to a pleiotropic spectrum of bioactive intermediates, which may function as potent co-factors of transcription factors or enzymes and contribute to the regulation of numerous cellular processes. From this point of view, the process of lipolysis not only provides energy-rich equivalents but also acquires a new regulatory function. In this review, we will concentrate on the role that fatty acids liberated from intracellular TAG stores play as signaling molecules. The first part provides an overview of the transcription factors, which are regulated by fatty acids derived from intracellular stores. The second part is devoted to the role of fatty acid signaling in different organs/tissues. The specific contribution of free fatty acids released by particular lipases, hormone-sensitive lipase, adipose triacylglycerol lipase and lysosomal lipase will also be discussed.

Binding of phage displayed Bacillus subtilis lipase A to a phosphonate suicide inhibitor

NARCIS (Netherlands)

Dröge, M.J; Ruggeberg, C.J.; van der Sloot, Almer Martinus; Schimmel, J.; Dijkstra, Durk; Verhaert, R.M D; Reetz, M.T.; Quax, Wim; Droge, MJ; Dijkstra, DS

2003-01-01

Phage display can be used as a protein engineering tool to select proteins with desirable binding properties from a library of randomly constructed mutants. Here, we describe the development of this method for the directed evolution of Bacillus subtilis lipase A, an enzyme that has marked properties

Characterization of the hormone-binding domain of the chicken c-erbA/thyroid hormone receptor protein

DEFF Research Database (Denmark)

Muñoz, A; Zenke, M; Gehring, U

1988-01-01

mutations present in the carboxy-terminal half of P75gag-v-erbA co-operate in abolishing hormone binding, and that the ligand-binding domain resides in a position analogous to that of steroid receptors. Furthermore, a point mutation that is located between the putative DNA and ligand-binding domains of P75......To identify and characterize the hormone-binding domain of the thyroid hormone receptor, we analyzed the ligand-binding capacities of proteins representing chimeras between the normal receptor and P75gag-v-erbA, the retrovirus-encoded form deficient in binding ligand. Our results show that several......gag-v-erbA and that renders it biologically inactive fails to affect hormone binding by the c-erbA protein. These results suggest that the mutation changed the ability of P75gag-v-erbA to affect transcription since it also had no effect on DNA binding. Our data also suggest that hormone...

Chylomicronemia with a mutant GPIHBP1 (Q115P) that cannot bind lipoprotein lipase

NARCIS (Netherlands)

Beigneux, Anne P; Franssen, Remco; Bensadoun, André; Gin, Peter; Melford, Kristan; Peter, Jorge; Walzem, Rosemary L; Weinstein, Michael M; Davies, Brandon S J; Kuivenhoven, Jan A; Kastelein, John J P; Fong, Loren G; Dallinga-Thie, Geesje M; Young, Stephen G

OBJECTIVE: GPIHBP1 is an endothelial cell protein that binds lipoprotein lipase (LPL) and chylomicrons. Because GPIHBP1 deficiency causes chylomicronemia in mice, we sought to determine whether some cases of chylomicronemia in humans could be attributable to defective GPIHBP1 proteins. METHODS AND

Lipase kinetics: hydrolysis of triacetin by lipase from Candida cylindracea in a hollow-fiber membrane reactor

NARCIS (Netherlands)

Guit, R.P.M.; Kloosterman, M.; Meindersma, G.W.; Mayer, M.; Meijer, E.M.

1991-01-01

The aptitude of a hollow-fiber membrane reactor to det. lipase kinetics was investigated using the hydrolysis of triacetin catalyzed by lipase from C. cylindracea as a model system. The binding of the lipase to the membrane appears not to be very specific (surface adsorption), and probably its

Extended hormone binding site of the human thyroid stimulating hormone receptor: distinctive acidic residues in the hinge region are involved in bovine thyroid stimulating hormone binding and receptor activation.

Science.gov (United States)

Mueller, Sandra; Kleinau, Gunnar; Jaeschke, Holger; Paschke, Ralf; Krause, Gerd

2008-06-27

The human thyroid stimulating hormone receptor (hTSHR) belongs to the glycoprotein hormone receptors that bind the hormones at their large extracellular domain. The extracellular hinge region of the TSHR connects the N-terminal leucine-rich repeat domain with the membrane-spanning serpentine domain. From previous studies we reasoned that apart from hormone binding at the leucine-rich repeat domain, additional multiple hormone contacts might exist at the hinge region of the TSHR by complementary charge-charge recognition. Here we investigated highly conserved charged residues in the hinge region of the TSHR by site-directed mutagenesis to identify amino acids interacting with bovine TSH (bTSH). Indeed, the residues Glu-297, Glu-303, and Asp-382 in the TSHR hinge region are essential for bTSH binding and partially for signal transduction. Side chain substitutions showed that the negative charge of Glu-297 and Asp-382 is necessary for recognition of bTSH by the hTSHR. Multiple combinations of alanine mutants of the identified positions revealed an increased negative effect on hormone binding. An assembled model suggests that the deciphered acidic residues form negatively charged patches at the hinge region resulting in an extended binding mode for bTSH on the hTSHR. Our data indicate that certain positively charged residues of bTSH might be involved in interaction with the identified negatively charged amino acids of the hTSHR hinge region. We demonstrate that the hinge region represents an extracellular intermediate connector for both hormone binding and signal transduction of the hTSHR.

Leu452His mutation in lipoprotein lipase gene transfer associated with hypertriglyceridemia in mice in vivo.

Directory of Open Access Journals (Sweden)

Kaiyue Sun

Full Text Available Mutated mouse lipoprotein lipase (LPL containing a leucine (L to histidine (H substitution at position 452 was transferred into mouse liver by hydrodynamics-based gene delivery (HD. Mutated-LPL (MLPL gene transfer significantly increased the concentrations of plasma MLPL and triglyceride (TG but significantly decreased the activity of plasma LPL. Moreover, the gene transfer caused adiposis hepatica and significantly increased TG content in mouse liver. To understand the effects of MLPL gene transfer on energy metabolism, we investigated the expression of key functional genes related to energy metabolism in the liver, epididymal fat, and leg muscles. The mRNA contents of hormone-sensitive lipase (HSL, adipose triglyceride lipase (ATGL, fatty acid-binding protein (FABP, and uncoupling protein (UCP were found to be significantly reduced. Furthermore, we investigated the mechanism by which MLPL gene transfer affected fat deposition in the liver, fat tissue, and muscle. The gene expression and protein levels of forkhead Box O3 (FOXO3, AMP-activated protein kinase (AMPK, and peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α were found to be remarkably decreased in the liver, fat and muscle. These results suggest that the Leu452His mutation caused LPL dysfunction and gene transfer of MLPL in vivo produced resistance to the AMPK/PGC-1α signaling pathway in mice.

A lipoprotein lipase (LPL)-specific monoclonal antibody, 88B8, that abolishes the binding of LPL to GPIHBP1

DEFF Research Database (Denmark)

Allan, Christopher M; Larsson, Mikael; Hu, Xuchen

2016-01-01

Lipoprotein lipase (LPL) contains two principal domains: an amino-terminal catalytic domain (residues 1-297) and a carboxyl-terminal domain (residues 298-448) that is important for binding lipids and binding GPIHBP1 (an endothelial cell protein that shuttles LPL to the capillary lumen). The LPL...

Persistent Graves' hyperthyroidism despite rapid negative conversion of thyroid-stimulating hormone-binding inhibitory immunoglobulin assay results: a case report.

Science.gov (United States)

Ohara, Nobumasa; Kaneko, Masanori; Kitazawa, Masaru; Uemura, Yasuyuki; Minagawa, Shinichi; Miyakoshi, Masashi; Kaneko, Kenzo; Kamoi, Kyuzi

2017-02-06

-stimulating hormone receptor antibody upon improvement of thyroid autoimmunity with thiamazole treatment. Physicians should keep in mind that patients with Graves' disease may show thyroid-stimulating hormone-binding inhibitory immunoglobulin assay results that do not reflect the severity of Graves' disease or indicate the outcome of the disease, and that active Graves' disease may persist even after negative results on thyroid-stimulating hormone-binding inhibitory immunoglobulin assays. Timely performance of thyroid function tests in combination with sensitive imaging tests, including thyroid ultrasound and scintigraphy, are necessary to evaluate the severity of Graves' disease and treatment efficacy.

Sex hormone-binding globulin levels predict insulin sensitivity, disposition index, and cardiovascular risk during puberty

DEFF Research Database (Denmark)

Sørensen, Kaspar; Aksglaede, Lise; Munch-Andersen, Thor

2009-01-01

Early puberty is associated with increased risk of subsequent cardiovascular disease. Low sex hormone-binding globulin (SHBG) levels are a feature of early puberty and of conditions associated with increased cardiovascular risk. The aim of the present study was to evaluate SHBG as a predictor...... of glucose metabolism and metabolic risk during puberty....

The effect of hyperthyroidism on opiate receptor binding and pain sensitivity

International Nuclear Information System (INIS)

Edmondson, E.A.; Bonnet, K.A.; Friedhoff, A.J.

1990-01-01

This study was conducted to determine the effect of thyroid hormone on opiate receptor ligand-binding and pain sensitivity. Specific opiate receptor-binding was performed on brain homogenates of Swiss-Webster mice. There was a significant increase in 3 H-naloxone-binding in thyroxine-fed subjects (hyperthyroid). Scatchard analysis revealed that the number of opiate receptors was increased in hyperthyroid mice (Bmax = 0.238 nM for hyperthyroid samples vs. 0.174 nM for controls). Binding affinity was unaffected (Kd = 1.54 nM for hyperthyroid and 1.58 nM for control samples). When mice were subjected to hotplate stimulation, the hyperthyroid mice were noted to be more sensitive as judged by pain aversion response latencies which were half that of control animals. After morphine administration, the hyperthyroid animals demonstrated a shorter duration of analgesia. These findings demonstrate that thyroxine increases opiate receptor number and native pain sensitivity but decreases the duration of analgesia from morphine

The effect of hyperthyroidism on opiate receptor binding and pain sensitivity

Energy Technology Data Exchange (ETDEWEB)

Edmondson, E.A. (Baylor College of Medicine, Houston, TX (USA)); Bonnet, K.A.; Friedhoff, A.J. (New York Univ. School of Medicine, NY (USA))

1990-01-01

This study was conducted to determine the effect of thyroid hormone on opiate receptor ligand-binding and pain sensitivity. Specific opiate receptor-binding was performed on brain homogenates of Swiss-Webster mice. There was a significant increase in {sup 3}H-naloxone-binding in thyroxine-fed subjects (hyperthyroid). Scatchard analysis revealed that the number of opiate receptors was increased in hyperthyroid mice (Bmax = 0.238 nM for hyperthyroid samples vs. 0.174 nM for controls). Binding affinity was unaffected (Kd = 1.54 nM for hyperthyroid and 1.58 nM for control samples). When mice were subjected to hotplate stimulation, the hyperthyroid mice were noted to be more sensitive as judged by pain aversion response latencies which were half that of control animals. After morphine administration, the hyperthyroid animals demonstrated a shorter duration of analgesia. These findings demonstrate that thyroxine increases opiate receptor number and native pain sensitivity but decreases the duration of analgesia from morphine.

Comparison of renal and osseous binding of parathyroid hormone and hormonal fragments

International Nuclear Information System (INIS)

Demay, M.; Mitchell, J.; Goltzman, D.

1985-01-01

The authors compared receptor binding and adenylate cyclase stimulation of intact bovine parathyroid hormone (bPTH)-(1-84) and the synthetic amino-terminal fragments, bPTH-(1-34) and rat PTH (rPTH)-(1-34). In both canine renal membranes and cloned rat osteosarcoma cells the amino-terminal fragments bound to a single order of sites; the affinity of rPTH-(1-34) exceeded that of bPTH-(1-34), correlating with its higher potency in stimulating adenylate cyclase. In studies with oxidized bPTH-(1--84), the middle and carboxyl regions of intact PTH were found to bind to both tissues but with higher affinity to osteosarcoma cells than to renal membranes. Our results demonstrate that rPTH-(1--34) is the most favorable probe of amino-terminal PTH binding and the most potent of the PTH peptides in stimulating renal and osseous adenylate cyclase. The results also show that midregion and carboxyl determinants within intact PTH contribute to hormone binding, which does not correlate with adenylate cyclase activation and appears more significant for skeletal than for renal binding

Controlled lid-opening in Thermomyces lanuginosus lipase- An engineered switch for studying lipase function

DEFF Research Database (Denmark)

Skjold-Jørgensen, Jakob; Vind, Jesper; Moroz, Olga V.

2017-01-01

Here, we present a lipase mutant containing a biochemical switch allowing a controlled opening and closing of the lid independent of the environment. The closed form of the TlL mutant shows low binding to hydrophobic surfaces compared to the binding observed after activating the controlled switch...... inducing lid-opening. We directly show that lipid binding of this mutant is connected to an open lid conformation demonstrating the impact of the exposed amino acid residues and their participation in binding at the water-lipid interface. The switch was created by introducing two cysteine residues......-D measurements revealed a seven-fold increase in binding rate for the unlocked lipase. The TlL_locked mutant shows structural changes across the protein important for understanding the mechanism of lid-opening and closing. Our experimental results reveal sites of interest for future mutagenesis studies aimed...

Iodine-125-labeled lipoprotein lipase as a tool to detect and study spontaneous lipolysis in bovine milk

International Nuclear Information System (INIS)

Sundheim, G.; Bengtsson-Olivecrona, G.

1986-01-01

The distribution of lipoprotein lipase among cream, casein, and milk serum can be evaluated by addition of a trace amount of 125 I-labeled lipoprotein lipase to milk. Radioactive lipase was distributed in parallel to endogenous lipase under several conditions. In some milk samples, binding of lipase to cream increased when the milk was cooled. Correlation was good between bound labeled lipase and degree of cold-induced lipolysis in corresponding milk samples. Binding of lipase to cream or to casein was not saturable by addition of two-to threefold more lipase than is normally present in milk. In milk with a relatively high fraction of lipase bound to cream, a correspondingly lower fraction was associated with casein, whereas the fraction of lipase in milk serum was similar in all milk samples. Cold-induced binding of lipoprotein lipase to cream was not fully reversed when the milk was warmed again. Heparin released lipase from casein and increased the amount of lipase bound to cream after cooling

Presence of specific growth hormone binding sites in rainbow trout (Oncorhynchus mykiss) tissues: characterization of the hepatic receptor

Energy Technology Data Exchange (ETDEWEB)

Yao, K.; Niu, P.D.; Le Gac, F.; Le Bail, P.Y. (Laboratoire de Physiologie des Poissons, INRA, Rennes, (France))

1991-01-01

The present work outlines the presence of specific binding for chinook salmon growth hormone (sGH) in different tissue preparations of rainbow trout. Optimal incubation conditions (pH, Tris, MgCl{sub 2}) were determined. Specific binding was very sensitive to salt concentration during incubation. The specific binding reached a plateau after 15 and 25 hr of incubation at 12 and 4 {degree}. At 20 {degree}, specific and nonspecific binding were not stable. Specific binding dissociation was slower than association and was only partial. The binding was saturable (Bmax = 187 +/- 167 pmol), of high affinity (Ka = 2.4 +/- 0.8 10(9) M-1), and very specific for GH, properties which are in agreement with the characteristics of hormonal receptors. Sea bream and mammalian GH appeared 2- and 30-fold, respectively, less potent than cold sGH2 for displacing {sup 125}I-sGH2. Tissue preparations from ovary, testis, fat, skin, cartilage, gill, blood pellet, brain, spleen, kidney, and muscle showed significant saturable binding.

Presence of specific growth hormone binding sites in rainbow trout (Oncorhynchus mykiss) tissues: characterization of the hepatic receptor

International Nuclear Information System (INIS)

Yao, K.; Niu, P.D.; Le Gac, F.; Le Bail, P.Y.

1991-01-01

The present work outlines the presence of specific binding for chinook salmon growth hormone (sGH) in different tissue preparations of rainbow trout. Optimal incubation conditions (pH, Tris, MgCl 2 ) were determined. Specific binding was very sensitive to salt concentration during incubation. The specific binding reached a plateau after 15 and 25 hr of incubation at 12 and 4 degree. At 20 degree, specific and nonspecific binding were not stable. Specific binding dissociation was slower than association and was only partial. The binding was saturable (Bmax = 187 +/- 167 pmol), of high affinity (Ka = 2.4 +/- 0.8 10(9) M-1), and very specific for GH, properties which are in agreement with the characteristics of hormonal receptors. Sea bream and mammalian GH appeared 2- and 30-fold, respectively, less potent than cold sGH2 for displacing 125 I-sGH2. Tissue preparations from ovary, testis, fat, skin, cartilage, gill, blood pellet, brain, spleen, kidney, and muscle showed significant saturable binding

Concentration of serum thyroid hormone binding proteins after 131I treatment of hyperthyroidism

International Nuclear Information System (INIS)

Harrop, J.S.; Hopton, M.R.; Lazarus, J.H.

1981-01-01

Serum concentrations of the thyroid hormone binding proteins, thyroxine binding globulin, prealbumin, and albumin were determined in 30 thyrotoxic patients before and after 131 I treatment. Each patient was placed into one of three groups according to response to treatment. The serum concentration of all three proteins rose significantly in 10 patients who became euthyroid, and a greater increase was seen in 10 patients who developed hypothyroidism. There was no significant change in thyroid hormone binding protein concentrations in 10 subjects who remained hyperthyroid. Changes in the concentration of thyroid hormone binding proteins should be borne in mind when total thyroid hormone concentrations are used to monitor the progress of patients receiving treatment for hyperthyroidism. (author)

Implications of surface charge and curvature for the binding orientation of Thermomyces lanuginosus lipase on negatively charged or zwitterionic phospholipid vesicles as studied by ESR spectroscopy

DEFF Research Database (Denmark)

Hedin, E.M.K.; Høyrup, Lise Pernille Kristine; Patkar, S.A.

2005-01-01

fluorescence quenching efficiency between each spin-label positioned on TLL, and the lipid membrane. ESR exposure and fluorescence quenching data show that TILL associates closer to the negatively charged PG surface than the zwitterionic PC surface, and binds to both POPG LUV and POPC SUV predominantly through......The triglyceride lipase (EC 3.1.1.3) Thermomyces lanuginosus lipase (TLL) binds with high affinity to unilamellar phospholipid vesicles that serve as a diluent interface for both lipase and substrate, but it displays interfacial activation on only small and negatively charged such vesicles [Cajal......) spectroscopy in combination with site-directed spin-labeling [Hedin, E. M. K., et al. (2002) Biochemistry 41, 1418514196]. In our investigation, we have studied the interfacial orientation of TLL when bound to large unilamellar vesicles (LUV) consisting of POPG, and bound to SUV consisting of 1-palmitoyl-2...

Application of a sensitive collection heuristic for very large protein families: Evolutionary relationship between adipose triglyceride lipase (ATGL and classic mammalian lipases

Directory of Open Access Journals (Sweden)

Berezovsky Igor

2006-03-01

Full Text Available Abstract Background Manually finding subtle yet statistically significant links to distantly related homologues becomes practically impossible for very populated protein families due to the sheer number of similarity searches to be invoked and analyzed. The unclear evolutionary relationship between classical mammalian lipases and the recently discovered human adipose triglyceride lipase (ATGL; a patatin family member is an exemplary case for such a problem. Results We describe an unsupervised, sensitive sequence segment collection heuristic suitable for assembling very large protein families. It is based on fan-like expanding, iterative database searches. To prevent inclusion of unrelated hits, additional criteria are introduced: minimal alignment length and overlap with starting sequence segments, finding starting sequences in reciprocal searches, automated filtering for compositional bias and repetitive patterns. This heuristic was implemented as FAMILYSEARCHER in the ANNIE sequence analysis environment and applied to search for protein links between the classical lipase family and the patatin-like group. Conclusion The FAMILYSEARCHER is an efficient tool for tracing distant evolutionary relationships involving large protein families. Although classical lipases and ATGL have no obvious sequence similarity and differ with regard to fold and catalytic mechanism, homology links detected with FAMILYSEARCHER show that they are evolutionarily related. The conserved sequence parts can be narrowed down to an ancestral core module consisting of three β-strands, one α-helix and a turn containing the typical nucleophilic serine. Moreover, this ancestral module also appears in numerous enzymes with various substrate specificities, but that critically rely on nucleophilic attack mechanisms.

Generalized resistance to thyroid hormone associated with a mutation in the ligand-binding domain of the human thyroid hormone receptor β

International Nuclear Information System (INIS)

Sakurai, A.; Takeda, K.; Ain, K.; Ceccarelli, P.; Nakai, A.; Seino, S.; Bell, G.I.; Refetoff, S.; DeGroot, L.J.

1989-01-01

The syndrome of generalized resistance to thyroid hormone is characterized by elevated circulating levels of thyroid hormone in the presence of an overall eumetabolic state and failure to respond normally to triiodothyronine. The authors have evaluated a family with inherited generalized resistance to thyroid hormone for abnormalities in the thyroid hormone nuclear receptors. A single guanine → cytosine replacement in the codon for amino acid 340 resulted in a glycine → arginine substitution in the hormone-binding domain of one of two alleles of the patient's thyroid hormone nuclear receptor β gene. In vitro translation products of this mutant human thyroid hormone nuclear receptor β gene did not bind triiodothyronine. Thus, generalized resistance to thyroid hormone can result from expression of an abnormal thyroid hormone nuclear receptor molecule

Effect of anticonvulsants on plasma testosterone and sex hormone binding globulin levels.

Science.gov (United States)

Barragry, J M; Makin, H L; Trafford, D J; Scott, D F

1978-01-01

Plasma sex hormone binding globulin (SHBG) and testosterone levels were measured in 29 patients with epilepsy (16 men and 13 women), most of them on chronic therapy with anticonvulsant drugs. Sex hormone binding globulin concentrations were increased in both sexes and testosterone levels in male patients. It is postulated that anticonvulsants may induce hepatic synthesis of SHBG. PMID:569688

Thyroid hormone receptor binds to a site in the rat growth hormone promoter required for induction by thyroid hormone

International Nuclear Information System (INIS)

Koenig, R.J.; Brent, G.A.; Warne, R.L.; Larsen, P.R.; Moore, D.D.

1987-01-01

Transcription of the rat growth hormone (rGH) gene in pituitary cells is increased by addition of thyroid hormone (T3). This induction is dependent on the presence of specific sequences just upstream of the rGH promoter. The authors have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. They show here that T3 receptor binds specifically to a site just upstream of the basal rGH promoter. This binding site includes two copies of a 7-base-pair direct repeat, the centers of which are separated by 10 base pairs. Deletions that specifically remove the T3 receptor binding site drastically reduce response to T3 in transient transfection experiments. These results demonstrate that T3 receptor can recognize specific DNA sequences and suggest that it can act directly as a positive transcriptional regulatory factor

Direct binding and activation of protein kinase C isoforms by steroid hormones.

LENUS (Irish Health Repository)

Alzamora, Rodrigo

2008-10-01

The non-genomic action of steroid hormones regulates a wide variety of cellular responses including regulation of ion transport, cell proliferation, migration, death and differentiation. In order to achieve such plethora of effects steroid hormones utilize nearly all known signal transduction pathways. One of the key signalling molecules regulating the non-genomic action of steroid hormones is protein kinase C (PKC). It is thought that rapid action of steroids hormones results from the activation of plasma membrane receptors; however, their molecular identity remains elusive. In recent years, an increasing number of studies have pointed at the selective binding and activation of specific PKC isoforms by steroid hormones. This has led to the hypothesis that PKC could act as a receptor as well as a transducer of the non-genomic effects of these hormones. In this review we summarize the current knowledge of the direct binding and activation of PKC by steroid hormones.

Hormone Therapy for Breast Cancer

Science.gov (United States)

... Common Cancer Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer ... sensitive breast cancer cells contain proteins called hormone receptors that become activated when hormones bind to them. ...

A mosquito hemolymph odorant-binding protein family member specifically binds juvenile hormone

Energy Technology Data Exchange (ETDEWEB)

Kim, Il Hwan; Pham, Van; Jablonka, Willy; Goodman, Walter G.; Ribeiro, José M. C.; Andersen, John F.

2017-07-27

Juvenile hormone (JH) is a key regulator of insect development and reproduction. In adult mosquitoes, it is essential for maturation of the ovary and normal male reproductive behavior, but how JH distribution and activity is regulated after secretion is unclear. Here, we report a new type of specific JH-binding protein, given the name mosquito juvenile hormone-binding protein (mJHBP), which circulates in the hemolymph of pupal and adult Aedes aegypti males and females. mJHBP is a member of the odorant-binding protein (OBP) family, and orthologs are present in the genomes of Aedes, Culex, and Anopheles mosquito species. Using isothermal titration calorimetry, we show that mJHBP specifically binds JH II and JH III but not eicosanoids or JH derivatives. mJHBP was crystallized in the presence of JH III and found to have a double OBP domain structure reminiscent of salivary “long” D7 proteins of mosquitoes. We observed that a single JH III molecule is contained in the N-terminal domain binding pocket that is closed in an apparent conformational change by a C-terminal domain-derived α-helix. The electron density for the ligand indicated a high occupancy of the natural 10R enantiomer of JH III. Of note, mJHBP is structurally unrelated to hemolymph JHBP from lepidopteran insects. A low level of expression of mJHBP in Ae. aegypti larvae suggests that it is primarily active during the adult stage where it could potentially influence the effects of JH on egg development, mating behavior, feeding, or other processes.

A mosquito hemolymph odorant-binding protein family member specifically binds juvenile hormone.

Science.gov (United States)

Kim, Il Hwan; Pham, Van; Jablonka, Willy; Goodman, Walter G; Ribeiro, José M C; Andersen, John F

2017-09-15

Juvenile hormone (JH) is a key regulator of insect development and reproduction. In adult mosquitoes, it is essential for maturation of the ovary and normal male reproductive behavior, but how JH distribution and activity is regulated after secretion is unclear. Here, we report a new type of specific JH-binding protein, given the name mosquito juvenile hormone-binding protein (mJHBP), which circulates in the hemolymph of pupal and adult Aedes aegypti males and females. mJHBP is a member of the odorant-binding protein (OBP) family, and orthologs are present in the genomes of Aedes , Culex , and Anopheles mosquito species. Using isothermal titration calorimetry, we show that mJHBP specifically binds JH II and JH III but not eicosanoids or JH derivatives. mJHBP was crystallized in the presence of JH III and found to have a double OBP domain structure reminiscent of salivary "long" D7 proteins of mosquitoes. We observed that a single JH III molecule is contained in the N-terminal domain binding pocket that is closed in an apparent conformational change by a C-terminal domain-derived α-helix. The electron density for the ligand indicated a high occupancy of the natural 10 R enantiomer of JH III. Of note, mJHBP is structurally unrelated to hemolymph JHBP from lepidopteran insects. A low level of expression of mJHBP in Ae. aegypti larvae suggests that it is primarily active during the adult stage where it could potentially influence the effects of JH on egg development, mating behavior, feeding, or other processes.

In vitro binding of steroid hormones by natural and purified fibers

International Nuclear Information System (INIS)

Shultz, T.D.; Howie, B.J.

1986-01-01

The in vitro binding of estrone, estradiol-17β, estriol, testosterone, dihydrotestosterone, and estrone-3-glucuronide by wheat, oat and corn brans, oat hulls, cellulose, lignin, and cholestyramine resin was measured. Steroid binding was carried out by mixing 50 mg of binding substance with varying substrate quantities (0.037 μCi; 0.50-2.51 pmol/incubation) of 3 H-estrone, 3 H-estradiol-17β, 3 H-estriol, 3 H-estrone-3-glucuronide, 4 H-testosterone, and 370 C for 1 hr with shaking. Following centrifugation of the reaction mixture, a 1 ml aliquot was analyzed for radioactivity. The extent of steroid sequestration was characteristic and reproducible for each hormone. Cholestyramine bound an average of 90% of all the steroids tested, whereas cellulose bound the least (12%). Of the other substances tested, lignin bound 87%; wheat and oat grans, 45% each; corn bran, 44%; and oat hulls, 32% of the unconjugated hormones. The conjugated steroid was less likely to bind than the unconjugated steroids. Lignin appeared to be an important component in the interaction with steroid hormones. The results support the hydrophobic of nature of adsorption and suggest that the components of the fiber in diet should be considered separately when evaluating in vivo metabolic effects. Implications include the possible modification of hormone-dependent cancer risk through dietary intervention

Lipase in milk, curd and cheese

NARCIS (Netherlands)

Geurts, T.J.; Lettink, F.J.; Wouters, J.T.M.

2003-01-01

Presence of lipase in milk, curd, whey and cheese was studied. A small amount of the product was added to a large volume of lipase-free whole milk that had been made sensitive to lipolysis by homogenization. Increase of the acidity of the fat in the mixture, determined after incubation, was

Lipase or amylase for the diagnosis of acute pancreatitis?

Science.gov (United States)

Ismail, Ola Z; Bhayana, Vipin

2017-12-01

Acute pancreatitis is a rapid onset of inflammation of the pancreas causing mild to severe life threatening conditions [1, 2]. In Canada, acute pancreatitis is the 5th most expensive digestive disease in Canada with a considerable economic burden on the health care system [3]. The diagnosis of acute pancreatitis is usually based on the presence of abdominal pain and elevated levels of serum amylase and/or lipase. Many health care centers use either serum amylase, lipase or both to diagnose acute pancreatitis without considering which one could provide a better diagnostic accuracy. The aim of this review is to investigate whether serum lipase alone is a sufficient biomarker for the diagnosis of acute pancreatitis. We have examined various studies looking at the utilization, sensitivity, specificity and cost associated savings of lipase and amylase in the diagnosis of acute pancreatitis. When comparing different studies, serum lipase offers a higher sensitivity than serum amylase in diagnosing acute pancreatitis. Lipase also offers a larger diagnostic window than amylase since it is elevated for a longer time, thus allowing it to be a useful diagnostic biomarker in early and late stages of acute pancreatitis. Several recent evidence-based guidelines recommend the use of lipase over amylase. Nevertheless, both lipase and amylase alone lack the ability to determine the severity and etiology of acute pancreatitis. The co-ordering of both tests has shown little to no increase in the diagnostic sensitivity and specificity. Thus, unnecessary testing and laboratory expenditures can be reduced by testing lipase alone. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Is the sex hormone binding globulin related to preeclampsia independent of insulin resistance

International Nuclear Information System (INIS)

Rahmanian, M.; Salari, Z.; Mirmohammadkhani, M.; Ghorbani, R.

2014-01-01

Objective: To evaluate the association between Sex Hormone Binding Globulin and preeclampsia in Iranian women considering the probable confounding effect of insulin resistance. Methods: The case-control study was conducted at the Semnan University of Medical Sciences, Iran, and comprised pregnant women who received prenatal care at Amiralmomenin Hospital in 2011. Cases represented patients admitted because of preeclampsia, while controls were randomly selected eligible pregnant women without hypertension and/or proteinuria. Fasting blood sugar and insulin were assessed for all participants as well as their blood concentration of Sex Hormone Binding Globulin. The Homeostasis Model Assessment of Insulin Resistance Score was used. The correlation between dependant and independent variables was reported by crude and adjusted odds ratio applying logistic regression models. SPSS 16.0 was used for statistical analysis. Results: Of the 100 pregnant women in the study, 45(45%) were cases. Insulin resistance was found to be significantly more frequent in the cases compared to the controls (adjusted odds ratio=2.78; 95% Confidence Interval: 1.11, 6.90; p<0.01). There was a significant reverse correlation between level of Sex Hormone Binding Globulin in blood and being a case of preeclampsia (adjusted odds ratio=0.99; 95% Confidence Interval: 0.98, 1.00; p=0.04). Conclusion: Independent of insulin resistance, every 1nmol/l increase in Sex Hormone Binding Globulin, decreases the odds of preeclampsia by 1%, notifying Sex Hormone Binding Globulin as an important biomarker about its etiology and prediction. (author)

Juvenile hormone-binding proteins of Melanoplus bivittatus identified by EFDA photoaffinity labeling

International Nuclear Information System (INIS)

Winder, B.S.

1988-01-01

Proteins that bind juvenile hormone in the hemolymph and fat body of the grasshopper, Melanoplus bivittatus were identified by photoaffinity labeling with radiolabeled epoxyfarnesyl diazoacetate ( 3 H-EFDA), and were characterized by electrophoretic analysis. A protocol was developed which allowed detection of 3 H-EFDA that was covalently linked to proteins upon exposure to ultraviolet light at 254 nm. Quantification of protein-linked 3 H-EFDA by liquid scintillation spectrometry took advantage of the differential solubility of unlinked 3 H-EFDA in toluene alone, and of the protein-linked 3 H-EFDA in toluene plus the detergent, Triton X-100. Competition between EFDA and juvenile hormone (JH) for binding to JH-specific binding sites was measured by hydroxyapatite protein binding assays in the presence of radiolabeled JH or EFDA and competing non-radiolabeled hormone. The protein-linked EFDA was detected on fluorograms of SDS or nondenaturing polyacrylamide gels (PAGE), and by liquid scintillation spectrometry of membranes to which the proteins had been electrophoretically transferred. Proteins which specifically bound JH were identified by photolabeling proteins in the presence and absence of nonlabeled JH-III

Maximization of Intracellular Lipase Production in a Lipase-Overproducing Mutant Derivative of Rhizopus oligosporus DGM 31: A Kinetic Study

Directory of Open Access Journals (Sweden)

Tehreema Iftikhar

2008-01-01

Full Text Available Regulation and maximization of lipase production in a mutant derivative of R. oligosporus has been investigated using different substrates, inoculum sizes, pH of the medium, temperature, and nitrogen sources in shake flask experiments and batch fermentation in a fermentor. The production of intracellular lipase was improved 3 times following medium optimization involving one-at-a-time approach and aeration in the fermentor. Interestingly, intracellular lipase was poorly induced by oils, instead its production was induced by sugars, mainly starch, lactose, sucrose, xylose, glucose and glycerol. Dependent variables studied were cell mass, lipase activity, lipase yield, lipase specific and volumetric rate of formation. It was confirmed that lipase production in the derepressed mutant is sufficiently uncoupled from catabolite repression. The results of average specific productivities at various temperatures worked out according to the Arrhenius equation revealed that mutation decreased the magnitude of enthalpy and entropy demand in the inactivation equilibrium during product formation, suggesting that mutation made the metabolic network of the organism thermally more stable. The highest magnitudes of volumetric productivity (QP=490 IU/(L·h and other product attributes of lipase formation occurring on optimized medium in the fermentor are greater than the values reported by other workers. The purified enzyme is monomeric in nature and exhibits stability up to 80 °C and pH=6.0–8.0. Activation energy, enthalpy and entropy of catalysis at 50 °C, and magnitudes of Gibbs free energy for substrate binding, transition state stabilization and melting point indicated that this lipase is highly thermostable.

Metabolic fate of rat heart endothelial lipoprotein lipase

International Nuclear Information System (INIS)

Chajek-Shaul, T.; Bengtsson-Olivecrona, G.; Peterson, J.; Olivecrona, T.

1988-01-01

When isolated rat hearts were perfused with medium containing 125I-labeled bovine lipoprotein lipase (LPL), they bound both lipase activity and radioactivity. More than 80% of the bound lipase could be rapidly released by heparin. Low concentrations of bovine LPL displaced 50-60% of the endogeneous, endothelial-bound LPL. Higher concentrations caused additional binding. Both binding and exchange were rapid processes. The hearts continuously released endogenous LPL into the medium. An antiserum that inhibited bovine but not rat LPL was used to differentiate endogeneous and exogeneous LPL activity. When the pool of endothelial LPL was labeled with bovine 125I-labeled LPL and then chased with unlabeled bovine LPL, approximately 50% of the labeled lipase was rapidly displaced. During chase perfusion with medium only, catalytically active bovine LPL appeared in the perfusate. The rate of release was similar to that observed for endogeneous LPL activity and amounted to 10-13% of the heparin-releasable fraction in the first 5 min of perfusion. There was little or no degradation of bovine 125I-labeled LPL to fragments or acid-soluble products. These results indicate that endothelial LPL is accessible for exchange with exogeneous LPL and that detachment rather than degradation may be the pathway for catabolism of endothelial LPL

Mechanism of acetaldehyde-induced deactivation of microbial lipases

Directory of Open Access Journals (Sweden)

Jaeger Karl E

2011-02-01

Full Text Available Abstract Background Microbial lipases represent the most important class of biocatalysts used for a wealth of applications in organic synthesis. An often applied reaction is the lipase-catalyzed transesterification of vinyl esters and alcohols resulting in the formation of acetaldehyde which is known to deactivate microbial lipases, presumably by structural changes caused by initial Schiff-base formation at solvent accessible lysine residues. Previous studies showed that several lipases were sensitive toward acetaldehyde deactivation whereas others were insensitive; however, a general explanation of the acetaldehyde-induced inactivation mechanism is missing. Results Based on five microbial lipases from Candida rugosa, Rhizopus oryzae, Pseudomonas fluorescens and Bacillus subtilis we demonstrate that the protonation state of lysine ε-amino groups is decisive for their sensitivity toward acetaldehyde. Analysis of the diverse modification products of Bacillus subtilis lipases in the presence of acetaldehyde revealed several stable products such as α,β-unsaturated polyenals, which result from base and/or amino acid catalyzed aldol condensation of acetaldehyde. Our studies indicate that these products induce the formation of stable Michael-adducts at solvent-accessible amino acids and thus lead to enzyme deactivation. Further, our results indicate Schiff-base formation with acetaldehyde to be involved in crosslinking of lipase molecules. Conclusions Differences in stability observed with various commercially available microbial lipases most probably result from different purification procedures carried out by the respective manufacturers. We observed that the pH of the buffer used prior to lyophilization of the enzyme sample is of utmost importance. The mechanism of acetaldehyde-induced deactivation of microbial lipases involves the generation of α,β-unsaturated polyenals from acetaldehyde which subsequently form stable Michael-adducts with the

Active serine involved in the stabilization of the active site loop in the Humicola lanuginosa lipase

DEFF Research Database (Denmark)

Peters, Günther H.j.; Svendsen, A.; Langberg, H.

1998-01-01

We have investigated the binding properties of and dynamics in Humicola lanuginosa lipase (HII) and the inactive mutant S146A (active Ser146 substituted with Ala) using fluorescence spectroscopy and molecular dynamics simulations, respectively. Hll and S146A show significantly different binding......, whereas only small changes are observed for I-Ill suggesting that the active site Lid in the latter opens more easily and hence more lipase molecules are bound to the liposomes. These observations are in agreement with molecular dynamics simulations and subsequent essential dynamics analyses. The results...... to substantial conformational alterations in the H. lanuginosa Lipase and different binding affinities....

Increases thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase by fusion of cellulose binding domain derived from Trichoderma reesei

International Nuclear Information System (INIS)

Thongekkaew, Jantaporn; Ikeda, Hiroko; Iefuji, Haruyuki

2012-01-01

Highlights: ► The CSLP and fusion enzyme were successfully expressed in the Pichia pastoris. ► The fusion enzyme was stable at 80 °C for 120-min. ► The fusion enzyme was responsible for cellulose-binding capacity. ► The fusion enzyme has an attractive applicant for enzyme immobilization. -- Abstract: To improve the thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase (CSLP), the cellulose-binding domain originates from Trichoderma reesei cellobiohydrolase I was engineered into C-terminal region of the CSLP (CSLP-CBD). The CSLP and CSLP-CBD were successfully expressed in the Pichia pastoris using the strong methanol inducible alcohol oxidase 1 (AOX1) promoter and the secretion signal sequence from Saccharomyces cerevisiae (α factor). The recombinant CSLP and CSLP-CBD were secreted into culture medium and estimated by SDS–PAGE to be 22 and 27 kDa, respectively. The fusion enzyme was stable at 80 °C and retained more than 80% of its activity after 120-min incubation at this temperature. Our results also found that the fusion of fungal exoglucanase cellulose-binding domain to CSLP is responsible for cellulose-binding capacity. This attribute should make it an attractive applicant for enzyme immobilization.

Increases thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase by fusion of cellulose binding domain derived from Trichoderma reesei

Energy Technology Data Exchange (ETDEWEB)

Thongekkaew, Jantaporn, E-mail: jantaporn_25@yahoo.com [Department of Biological Science, Faculty of Science, Ubon-Ratchathani University, Warinchumrab, Ubon-Ratchathani 34190 (Thailand); Ikeda, Hiroko; Iefuji, Haruyuki [Application Research Division, National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

2012-03-30

Highlights: Black-Right-Pointing-Pointer The CSLP and fusion enzyme were successfully expressed in the Pichia pastoris. Black-Right-Pointing-Pointer The fusion enzyme was stable at 80 Degree-Sign C for 120-min. Black-Right-Pointing-Pointer The fusion enzyme was responsible for cellulose-binding capacity. Black-Right-Pointing-Pointer The fusion enzyme has an attractive applicant for enzyme immobilization. -- Abstract: To improve the thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase (CSLP), the cellulose-binding domain originates from Trichoderma reesei cellobiohydrolase I was engineered into C-terminal region of the CSLP (CSLP-CBD). The CSLP and CSLP-CBD were successfully expressed in the Pichia pastoris using the strong methanol inducible alcohol oxidase 1 (AOX1) promoter and the secretion signal sequence from Saccharomyces cerevisiae ({alpha} factor). The recombinant CSLP and CSLP-CBD were secreted into culture medium and estimated by SDS-PAGE to be 22 and 27 kDa, respectively. The fusion enzyme was stable at 80 Degree-Sign C and retained more than 80% of its activity after 120-min incubation at this temperature. Our results also found that the fusion of fungal exoglucanase cellulose-binding domain to CSLP is responsible for cellulose-binding capacity. This attribute should make it an attractive applicant for enzyme immobilization.

Partial disruption of lipolysis increases postexercise insulin sensitivity in skeletal muscle despite accumulation of DAG

DEFF Research Database (Denmark)

Serup, Annette Karen Lundbeck; Alsted, Thomas Junker; Jordy, Andreas Børsting

2016-01-01

reactivity in vitro, we investigated if the described function of DAGs as mediators of lipid-induced insulin resistance was depending on the different DAG-isomers. We measured insulin stimulated glucose uptake in hormone sensitive lipase (HSL) knock out (KO) mice after treadmill exercise to stimulate...

PDHK-2 deficiency is associated with attenuation of lipase-mediated fat consumption for the increased survival of Caenorhabditis elegans dauers.

Directory of Open Access Journals (Sweden)

Sunhee Kim

Full Text Available In Caenorhabditis elegans, slow fat consumption has been suggested to contribute to the extension of the survival rate during nutritionally adverse conditions. Here, we investigated the potential role of pyruvate dehydrogenase kinase (PDHK-2, the C. elegans homolog of mammalian PDK, effects on fat metabolism under nutritional conditions. PDHK-2 was expressed at low levels under well-fed conditions but was highly induced during long-term starvation and in the dauer state. This increase in pdhk-2 expression was regulated by both DAF-16 and NHR-49. Dauer-specific induction of PDHK-2 was abolished upon entry into the post-dauer stage. Interestingly, in the long-term dauer state, stored fat levels were higher in daf-2(e1370;pdhk-2 double mutants than in daf-2(e1370, suggesting a positive relationship between PDHK-2 activity and fat consumption. PDHK-2 deficiency has been shown to lead to greater preservation of residual fats, which would be predicted to contribute to survival during the dauer state. A test of this prediction showed that the survival rates of daf-2(e1370;pdhk-2(tm3075 and daf-2(e1370;pdhk-2(tm3086 double mutants were higher than that of daf-2(e1370, suggesting that loss of either the ATP-binding domain (tm3075 or branched chain keto-acid dehydrogenase kinase domain (tm3086 of PDHK-2 leads to reduced fat consumption and thus favors increased dauer survival. This attenuated fat consumption in the long-term dauer state of C. elegans daf-2 (e1370;pdhk-2 mutants was associated with concomitant down-regulation of the lipases ATGL (adipose triglyceride lipase, HSL (hormone-sensitive lipase, and C07E3.9 (phospholipase. In contrast, PDHK-2 overexpression in wild-type starved worms induced lipase expression and promoted abnormal dauer formation. Thus, we propose that PDHK-2 serves as a molecular bridge, connecting fat metabolism and survival under nutritionally adverse conditions in C. elegans.

Desethylamiodarone is a competitive inhibitor of the binding of thyroid hormone to the thyroid hormone alpha 1-receptor protein

NARCIS (Netherlands)

van Beeren, H. C.; Bakker, O.; Wiersinga, W. M.

1995-01-01

Desethylamiodarone (DEA), the major metabolite of the potent antiarrythmic drug amiodarone, is a non-competitive inhibitor of the binding of thyroid hormone (T3) to the beta 1-thyroid hormone receptor (T3R). In the present study, we investigated whether DEA acts in a similar way with respect to the

NMR assignments of juvenile hormone binding protein in complex with JH III.

Science.gov (United States)

Suzuki, Rintaro; Tase, Akira; Fujimoto, Zui; Shiotsuki, Takahiro; Yamazaki, Toshimasa

2009-06-01

A hemolymph juvenile hormone binding protein (JHBP) shuttles hydrophobic JH, a key hormone in regulation of the insect life cycle, from the site of the JH biosynthesis to the cells of target organs. We report complete NMR chemical shift assignments of Bombyx mori JHBP in the JH III-bound state.

Binding orientation and interaction of bile salt in its ternary complex with pancreatic lipase-colipase system.

Science.gov (United States)

Haque, Neshatul; Prakash Prabhu, N

2018-05-23

The interfacial activity of pancreatic lipases (PL) depends on the presence of colipase and bile salt. The activity of PL is inhibited by micellar concentrations of bile salt which can be restored by the addition of colipase. Though the formation of 1:1:1 tertiary complex by lipase-colipase-bile salt micelle is well accepted, the residue-level interactions between lipase-colipase and bile salt are yet to be clearly understood. Molecular dynamic simulations of lipase-colipase complex, lipase and colipase were performed in the presence of a model bile salt, sodium taurocholate (NaTC), at its near-CMC and supra-micellar concentrations. From the interactions obtained from the molecular dynamic simulations, the ternary complex was modelled and compared with earlier reports. The analysis suggested that a micelle of NaTC consisting of nine monomers was formed at the concave groove between lipase and colipase chain and it mainly interacted with the fourth finger of colipase. This complex was mainly stabilized by van der Waals interactions. Interestingly, the C-terminal domain of lipase which holds the colipase did not show any significant role in formation or stabilization of NaTC micelle. Copyright © 2018 Elsevier Inc. All rights reserved.

Sex hormone binding globulin phenotypes

DEFF Research Database (Denmark)

Cornelisse, M M; Bennett, Patrick; Christiansen, M

1994-01-01

Human sex hormone binding globulin (SHBG) is encoded by a normal and a variant allele. The resulting SHBG phenotypes (the homozygous normal SHBG, the heterozygous SHBG and the homozygous variant SHBG phenotype) can be distinguished by their electrophoretic patterns. We developed a novel detection....... This method of detection was used to determine the distribution of SHBG phenotypes in healthy controls of both sexes and in five different pathological conditions characterized by changes in the SHBG level or endocrine disturbances (malignant and benign ovarian neoplasms, hirsutism, liver cirrhosis...... on the experimental values. Differences in SHBG phenotypes do not appear to have any clinical significance and no sex difference was found in the SHBG phenotype distribution....

Biochemical Characterization of Lipases Obtained from Acinetobacter psychrotolerans Strains

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Şule SEREN

2017-12-01

Full Text Available In this study, extracellular lipases obtained from Acinetobacter psychrotolerans strains (Xg1 and Xg2 were characterized. The effects of varying pH values (3.0-10.0 and various temperatures (10-90 °C on lipase activities were examined. Also the effects of different metal ions, organic solvents and detergents on lipases were studied. The extracellular crude lipases were concentrated using ultrafiltration. Zymogram analysis of these lipases was performed. Lipases exhibited maximum activity at pH 8 and 30 °C.  While lipase obtained from the Xg1 strain exhibited the highest stability in the presence of various organic solvents, including hexane, ethyl acetate, chloroform and N,N dietil formamide, lipase obtained from the Xg2 strain was sensitive in the presence of isopropanol, acetonitrile, and butan-1-ol. The lipases of the Xg1 and Xg2 strains were inhibited in the presence of Cu2+ and Zn2+. Also, the lipase of the Xg1 strain was inhibited in the presence of Fe3+. In the presence of EDTA, the lipase activities of the Xg1 and Xg2 strains were partially inhibited. In presence of SDS, they were exactly inhibited. According to the zymogram results, the molecular weights of the lipases obtained from the Acinetobacter psychrotolerans Xg1 and Xg2 strains have been found approximately 37 and 30 kDa, respectively.

The specific binding of the thyroid hormones to matrix isolated from rat liver nuclei

International Nuclear Information System (INIS)

Wilson, B.D.; Albrecht, C.F.; Wium, C.A.

1982-01-01

Specific binding sites for the thyroid hormones have been demonstrated in the liver nuclear matrix, a structural framework of the nucleus. When labelled 3,5,3'-tri-iodo-L-thyronine ([ 125 l]T 3 ) is injected into rats, 5% of the total nucleus bound T 3 is bound to the matrix after 1 hour. However, when either isolated nuclei or isolated nuclear matrices were incubated with[ 125 l]T 3 in vitro, a 3- to 7- fold greater number of specific T 3 binding sites were revealed in the nuclear matrix. The properties of the matrix-associated thyroid hormone binding sites were investigated in vitro. These binding sites showed limited capacity and high affinity for T 3 ; the equilibrium association constant (K(a)) was 1,3X10 M -1 and the binding capacity was 20,2 fmol T 3 per 100 μg matrix protein

Luteinizing hormone-releasing hormone inactivation by purified pituitary plasma membranes: effects of receptor-binding studies.

Science.gov (United States)

Clayton, R N; Shakespear, R A; Duncan, J A; Marshall, J C

1979-05-01

Inactivation of LHRH by purified bovine pituitary plasma membranes was studied in vitro. After incubation of [125I]iodo-LHRH with plasma membranes, the amount of tracer bound to the pellet was measured, and the integrity of the unbound tracer in the supernatant was assessed. Reduction in ability to bind to anti-LHRH serum and to rebind to plasma membranes together with altered electrophoretic mobility on polyacrylamide gels showed that the unbound [125I]iodo-LHRH was inactivated. LHRH inactivation occurred rapidly and was dependent upon membrane concentration and incubation temperature. These results indicate that hormone inactivation must be taken into account in the interpretation of LHRH-receptor interactions. During 37 C incubations, the apparent absence of specific LHRH binding can be explained by inactivation of tracer hormone. Significant LHRH inactivation also occurred at 0 C, which in part explains the insensitivity of LHRH receptor assays. Assessment of LHRH inactivation by different particulate subcellular fractions of pituitary tissue showed that the inactivating enzyme was associated with the plasma membranes; other organelles did not alter LHRH. The enzyme appeared to be an integral part of the plasma membrane structure, since enzymic activity could not be removed by washing without reducing specific LHRH binding. Additionally, reduction of LHRH inactivation by the inhibitors Bacitracin and Trasylol and by magnesium was also accompanied by reduced LHRH binding. Previous studies have shown that the majority of LHRH binding to pituitary plasma membranes is to the low affinity site (approximately 10(-6) M), but the significance of this binding has been uncertain. Our findings indicate that low affinity binding probably represents binding of LHRH to the inactivating enzyme. The LHRH analog, D-Ser6(TBu), des Gly10, ethylamide, has greater biological activity than LHRH and is not inactivated to a significant extent by pituitary plasma membranes. The

PPARγ regulates exocrine pancreas lipase.

Science.gov (United States)

Danino, Hila; Naor, Ronny Peri-; Fogel, Chen; Ben-Harosh, Yael; Kadir, Rotem; Salem, Hagit; Birk, Ruth

2016-12-01

Pancreatic lipase (triacylglycerol lipase EC 3.1.1.3) is an essential enzyme in hydrolysis of dietary fat. Dietary fat, especially polyunsaturated fatty acids (PUFA), regulate pancreatic lipase (PNLIP); however, the molecular mechanism underlying this regulation is mostly unknown. As PUFA are known to regulate expression of proliferator-activated receptor gamma (PPARγ), and as we identified in-silico putative PPARγ binding sites within the putative PNLIP promoter sequence, we hypothesized that PUFA regulation of PNLIP might be mediated by PPARγ. We used in silico bioinformatics tools, reporter luciferase assay, PPARγ agonists and antagonists, PPARγ overexpression in exocrine pancreas AR42J and primary cells to study PPARγ regulation of PNLIP. Using in silico bioinformatics tools we mapped PPARγ binding sites (PPRE) to the putative promoter region of PNLIP. Reporter luciferase assay in AR42J rat exocrine pancreas acinar cells transfected with various constructs of the putative PNLIP promoter showed that PNLIP transcription is significantly enhanced by PPARγ dose-dependently, reaching maximal levels with multi PPRE sites. This effect was significantly augmented in the presence of PPARγ agonists and reduced by PPARγ antagonists or mutagenesis abrogating PPRE sites. Over-expression of PPARγ significantly elevated PNLIP transcript and protein levels in AR42J cells and in primary pancreas cells. Moreover, PNLIP expression was up-regulated by PPARγ agonists (pioglitazone and 15dPGJ2) and significantly down-regulated by PPARγ antagonists in non-transfected rat exocrine pancreas AR42J cell line cells. PPARγ transcriptionally regulates PNLIP gene expression. This transcript regulation resolves part of the missing link between dietary PUFA direct regulation of PNLIP. Copyright © 2016 Elsevier B.V. All rights reserved.

Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation.

Science.gov (United States)

Dittmer, W U; de Kievit, P; Prins, M W J; Vissers, J L M; Mersch, M E C; Martens, M F W C

2008-09-30

A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions as well as the bound/free separation are entirely controlled by magnetic forces induced by electromagnets above and below the sensor chip. During the assay, particles conjugated with tracer antibodies are actuated through the sample for target capture, and rapidly brought to the sensor surface where they bind to immobilized capture antibodies. Weakly or unbound labels are removed with a magnetic force oriented away from the GMR sensor surface. For the measurement of parathyroid hormone (PTH), a detection limit in the 10 pM range is obtained with a total assay time of 15 min when 300 nm particles are used. The same sensitivity can be achieved in 5 min when 500 nm particles are used. If 500 nm particles are employed in a 15-minute assay, then 0.8 pM of PTH is detectable. The low sample volume, high analytical performance and high speed of the test coupled with the compact GMR biosensor make the system especially suitable for sensitive testing outside of laboratory environments.

Effect of immobilized lipase supplementation of diets on the performance of the Japanese quails

International Nuclear Information System (INIS)

Abu-Taleb, A.M.; Ezzat, I.E.; Saleh, M.

2004-01-01

In the present study, lipase was immobilized onto two different supports, agarose and gelatin. Some physico-chemical properties of the free and immobilized lipase such as optimum temperature, optimum ph and storage stability were studied. Storage of the enzymes for 2 months showed that the free enzyme lost its activity, while the immobilized on the gelatin showed better resistance towards ph and temperature variations than that immobilized onto agarose. Four experiments were conducted to test the effect of the immobilized lipase supplementation on the productive performance of the Japanese quails. During the first 3 weeks, the addition of lipase to poultry diets caused an increase in the body weight gain of birds than the enzyme-free diet. An obvious improvement in quail day egg production during the laying period was observed with the groups fed on a diet supplemented with 3000 and 2000 I U of immobilized lipase per kilogram feed. Blood cholesterol was not affected with lipase addition, while total lipids were significantly increased. Significant reduction was also observed in thyroid hormones (T 3 and T 4 ) as compared with the control group

A simplified method for active-site titration of lipases immobilised on hydrophobic supports.

Science.gov (United States)

Nalder, Tim D; Kurtovic, Ivan; Barrow, Colin J; Marshall, Susan N

2018-06-01

The aim of this work was to develop a simple and accurate protocol to measure the functional active site concentration of lipases immobilised on highly hydrophobic supports. We used the potent lipase inhibitor methyl 4-methylumbelliferyl hexylphosphonate to titrate the active sites of Candida rugosa lipase (CrL) bound to three highly hydrophobic supports: octadecyl methacrylate (C18), divinylbenzene crosslinked methacrylate (DVB) and styrene. The method uses correction curves to take into account the binding of the fluorophore (4-methylumbelliferone, 4-MU) by the support materials. We showed that the uptake of the detection agent by the three supports is not linear relative to the weight of the resin, and that the uptake occurs in an equilibrium that is independent of the total fluorophore concentration. Furthermore, the percentage of bound fluorophore varied among the supports, with 50 mg of C18 and styrene resins binding approximately 64 and 94%, respectively. When the uptake of 4-MU was calculated and corrected for, the total 4-MU released via inhibition (i.e. the concentration of functional lipase active sites) could be determined via a linear relationship between immobilised lipase weight and total inhibition. It was found that the functional active site concentration of immobilised CrL varied greatly among different hydrophobic supports, with 56% for C18, compared with 14% for DVB. The described method is a simple and robust approach to measuring functional active site concentration in immobilised lipase samples. Copyright © 2018 Elsevier Inc. All rights reserved.

Hormone assay

International Nuclear Information System (INIS)

Eisentraut, A.M.

1977-01-01

An improved radioimmunoassay is described for measuring total triiodothyronine or total thyroxine levels in a sample of serum containing free endogenous thyroid hormone and endogenous thyroid hormone bound to thyroid hormone binding protein. The thyroid hormone is released from the protein by adding hydrochloric acid to the serum. The pH of the separated thyroid hormone and thyroid hormone binding protein is raised in the absence of a blocking agent without interference from the endogenous protein. 125 I-labelled thyroid hormone and thyroid hormone antibodies are added to the mixture, allowing the labelled and unlabelled thyroid hormone and the thyroid hormone antibody to bind competitively. This results in free thyroid hormone being separated from antibody bound thyroid hormone and thus the unknown quantity of thyroid hormone may be determined. A thyroid hormone test assay kit is described for this radioimmunoassay. It provides a 'single tube' assay which does not require blocking agents for endogenous protein interference nor an external solid phase sorption step for the separation of bound and free hormone after the competitive binding step; it also requires a minimum number of manipulative steps. Examples of the assay are given to illustrate the reproducibility, linearity and specificity of the assay. (UK)

Synthesis and binding affinity of an iodinated juvenile hormone

Energy Technology Data Exchange (ETDEWEB)

Prestwich, G.D.; Eng, W.S.; Robles, S.; Vogt, R.G.; Wisniewski, J.R.; Wawrzenczyk, C.

1988-01-25

The synthesis of the first iodinated juvenile hormone (JH) in enantiomerically enriched form is reported. This chiral compound, 12-iodo-JH I, has an iodine atom replacing a methyl group of the natural insect juvenile hormone, JH I, which is important in regulating morphogenesis and reproduction in the Lepidoptera. The unlabeled compound shows approximately 10% of the relative binding affinity for the larval hemolymph JH binding protein (JHBP) of Manduca sexta, which specifically binds natural /sup 3/H-10R,11S-JH I (labeled at 58 Ci/mmol) with a KD of 8 X 10(-8) M. It is also approximately one-tenth as biologically active as JH I in the black Manduca and epidermal commitment assays. The 12-hydroxy and 12-oxo compounds are poor competitors and are also biologically inactive. The radioiodinated (/sup 125/I)12-iodo-JH I can be prepared in low yield at greater than 2500 Ci/mmol by nucleophilic displacement using no-carrier-added /sup 125/I-labeled sodium iodide in acetone; however, synthesis using sodium iodide carrier to give the approximately 50 Ci/mmol radioiodinated ligand proceeds in higher radiochemical yield with fewer by-products and provides a radioligand which is more readily handled in binding assays. The KD of (/sup 125/I)12-iodo-JH I was determined for hemolymph JHBP of three insects: M. sexta, 795 nM; Galleria mellonella, 47 nM; Locusta migratoria, 77 nM. The selectivity of 12-iodo-JH I for the 32-kDa JHBP of M. sexta was demonstrated by direct autoradiography of a native polyacrylamide gel electrophoresis gel of larval hemolymph incubated with the radioiodinated ligand. Thus, the in vitro and in vivo activity of 12-iodo-JH I indicate that it can serve as an important new gamma-emitting probe in the search for JH receptor proteins in target tissues.

Analysis of the hormone-binding domain of steroid receptors using chimeras generated by homologous recombination

International Nuclear Information System (INIS)

Martinez, Elisabeth D.; Pattabiraman, Nagarajan; Danielsen, Mark

2005-01-01

The glucocorticoid receptor and the mineralocorticoid receptor are members of the steroid receptor family that exhibit ligand cross-reactivity. Specificity of steroid receptor action is investigated in the present work by the construction and characterization of chimeras between the glucocorticoid receptor and the mineralocorticoid receptor. We used an innovative approach to make novel steroid receptor proteins in vivo that in general, contrary to our expectations, show increased ligand specificity compared to the parental receptors. We describe a receptor that is specific for the potent synthetic glucocorticoid triamcinolone acetonide and does not bind aldosterone. A further set of chimeras has an increased ability to discriminate between ligands, responding potently to mineralocorticoids and only very weakly to synthetic glucocorticoids. A chimera with the fusion site in the hinge highlights the importance of the region between the DNA-binding and the hormone-binding domains since, unlike both the glucocorticoid and mineralocorticoid receptors, it only responds to mineralocorticoids. One chimera has reduced specificity in that it acts as a general corticoid receptor, responding to glucocorticoids and mineralocorticoids with similar potency and efficacy. Our data suggest that regions of the glucocorticoid and mineralocorticoid receptor hormone-binding domains are functionally non-reciprocal. We present transcriptional, hormone-binding, and structure-modeling evidence that suggests that receptor-specific interactions within and across domains mediate aspects of specificity in transcriptional responses to steroids

Endothelial lipase is a major determinant of HDL level

Energy Technology Data Exchange (ETDEWEB)

Ishida, Tatsuro; Choi, Sungshin; Kundu, Ramendra K.; Hirata, Ken-Ichi; Rubin, Edward M.; Cooper, Allen D.; Quertermous, Thomas

2003-01-30

lipase (44 percent identity) and hepatic lipase (41 percent identity), two well-characterized lipases that function at vascular endothelial surfaces. Critical motifs associated with lipase activity (GXSXG and the catalytic triad S169, D193, H274), and with heparin binding were strongly conserved. Interestingly, in contrast to both lipoprotein lipase and hepatic lipase, endothelial lipase has little triglyceride hydrolase activity in vitro but instead cleaves fatty acids from the sn-1 position of phosphatidylcho-line. In in vitro assays the enzyme is most active on lipids presented in HDL, although it will release fatty acids from all classes of lipoproteins. Consistent with this finding, adenovirus-mediated overexpression of endothelial lipase in LDL receptor-deficient mice reduced plasma concentrations of VLDL and LDL cholesterol by about 50 percent, whereas HDL-C decreased to almost zero in these animals. These data suggested that endothelial lipase may play a role in HDL catabolism.

Inositol metabolism in WRK-1 cells. Relationship of hormone-sensitive to -insensitive pools of phosphoinositides

International Nuclear Information System (INIS)

Monaco, M.E.

1987-01-01

Previous studies have indicated the existence of two separate pools of phosphoinositides in WRK-1 cells; one is labile and hormone-sensitive with respect to turnover, while the other is stable. Hormonal stimulation results in a rapid increase in 32 Pi incorporation into the sensitive pool, while in the absence of hormone, incorporation of 32 Pi into this pool is slow. Results are quite different when [ 3 H]inositol is the precursor utilized. Incorporation of [ 3 H]inositol into hormone-sensitive phosphoinositides is not stimulated in the presence of hormone, suggesting entry of this exogenous precursor into the cycle by a route other than the resynthetic phase of the cycle. Furthermore, failure of hormone to induce loss of [ 3 H]phosphoinositide in pulse-chase experiments in the absence of lithium suggests reutilization of the [ 3 H]inositol moiety generated by phosphodiesteratic cleavage of hormone-sensitive phosphoinositide. Time course studies indicate that the relative rates of incorporation of [ 3 H]inositol into sensitive and insensitive phosphoinositide remain constant from 2 to 24 h. Several factors are capable of increasing [ 3 H]inositol incorporation into hormone-insensitive phosphoinositide including vasopressin, calcium ionophores, and manganese. On the other hand, vasopressin treatment appears to decrease incorporation of [ 3 H]inositol into the hormone-sensitive pool, probably by shifting the equilibrium between phosphoinositides and inositol phosphates, since the decrease in radioactivity observed in the phosphoinositides is equaled by the increase observed in that in the inositol phosphates

Immobilization of Lipase from Geobacillus sp. and Its Application in Synthesis of Methyl Salicylate.

Science.gov (United States)

Bhardwaj, Kamal Kumar; Saun, Nitin Kumar; Gupta, Reena

2017-04-03

The present study showed unique properties of an alkaline, thermophilic lipase of Geobacillus sp. which was isolated from soil of hot spring. The study was aimed to investigate the optimum immobilization conditions of lipase onto silica gel matrix (100-200 mesh) by surface adsorption method and its application in the synthesis of methyl salicylate. Lipase immobilized by surface adsorption onto silica pretreated with 4% glutaraldehyde showed 74.67% binding of protein and the optimum binding time for glutaraldehyde was found to be 2 h. The enzyme showed maximum activity at temperature 55°C, incubation time of 10 min at pH 9.5 of Tris buffer (0.1 M). Free as well as immobilized lipase was more specific to p-NPP (20 mM). All the metal ions and detergents used had inhibitory effect on free as well as immobilized enzyme. The silica immobilized enzyme was reused for hydrolysis and it retained almost 40.78% of its original activity up to 4 th cycle. On optimizing different parameters such as molar ratio, incubation time, temperature, amount of enzyme, amount of molecular sieve, the % yield of methyl salicylate was found to be 82.94.

Medicinal plant phytochemicals and their inhibitory activities against pancreatic lipase: molecular docking combined with molecular dynamics simulation approach.

Science.gov (United States)

Ahmed, Bilal; Ali Ashfaq, Usman; Usman Mirza, Muhammad

2018-05-01

Obesity is the worst health risk worldwide, which is linked to a number of diseases. Pancreatic lipase is considered as an affective cause of obesity and can be a major target for controlling the obesity. The present study was designed to find out best phytochemicals against pancreatic lipase through molecular docking combined with molecular dynamics (MD) simulation. For this purpose, a total of 3770 phytochemicals were docked against pancreatic lipase and ranked them on the basis of binding affinity. Finally, 10 molecules (Kushenol K, Rosmarinic acid, Reserpic acid, Munjistin, Leachianone G, Cephamycin C, Arctigenin, 3-O-acetylpadmatin, Geniposide and Obtusin) were selected that showed strong bonding with the pancreatic lipase. MD simulations were performed on top five compounds using AMBER16. The simulated complexes revealed stability and ligands remained inside the binding pocket. This study concluded that these finalised molecules can be used as drug candidate to control obesity.

A radioreceptor assay of luteinizing hormone-releasing hormone receptor and characterization of LHRH binding to pituitary receptors in Shao duck

International Nuclear Information System (INIS)

Yang Peixin; Wu Meiwen; Chen Ziyuan

2000-01-01

The properties of Shao duck pituitary luteinizing hormone-releasing hormone (LHRH) receptors were analyzed in pituitary membrane preparation and isolated pituitary cells prepared by enzymatic dispersion with collagenase and trypsin, by using a super-agonist analog of (D-Lys 6 ) LHRH. High binding of 125 I-(D-Lys 6 ) LHRH to 10 6 cultured cells of Shao duck was observed after a 90 minute incubation at 4 degree C, while binding was significantly reduced after a 24h incubation. Binding of the radioligand was a function of tissue concentration of Shao duck pituitary membrane preparation, with a positive correlation over the range of 1-2 pituitary per-tube. Specific binding for 125 I-(D-Lys 6 ) LHRH increased with the increase in the amount of 125 I-(D-Lys 6 ) LHRH. The Scatchard analysis of data revealed a linear relationship between the amount of specific binding and the ratio of specific binding to free 1 '2 5 I(D-Lys 6 )LHRH, indicating a single class of high affinity sites. Equilibrium dissociation constant (Kd) was 0.34 nM in pituitary membrane preparation and 0.43 nM in isolated pituitary cells. Both Kd values were near and the maximum binding capacity (B max ) was great in isolated cells, suggesting no significant loss of the LHRH receptor population caused by the enzymatic procedure employed for cell dispersion in the present study. Addition of 9D-Lys 6 ) LHRH displaced bound 125 I-(D-Lys 6 ) LHRH. These results demonstrated the presence and provided characterization of LHRH receptors in Shao duck pituitary

Structural studies on lipoprotein lipase

International Nuclear Information System (INIS)

Socorro, L.

1985-01-01

The structure of lipoprotein lipase is not known. The lack of information on its primary sequence has been due to the inability of preparing it in homogeneous and stable form. This research has focused on the structural characterization of lipoprotein lipase. The first approach taken was to develop a purification method using bovine milk and affinity chromatography on heparin-Sepharose. The protein obtained was a heterogeneous peak with the activity shifted towards the trailing edge fractions. These fractions only presented a 55 Kdalton band on polyacrylamide gel electrophoresis. Monoclonal antibodies against this band detected an endogenous, phenyl methane sulfonyl fluoride-sensitive protease responsible for the presence of lower molecular weight fragments. The second approach was to label the lipoprotein lipase with a radioactive, active site, directed probe. After incubation and affinity chromatography a complex [ 3 H]inhibitor enzyme was isolated with a stoichiometry of 1.00 +/- 0.2. The complex was digested with CNBr and the insoluble peptides at low ionic strength (>90% [ 3 H]dpm) were used for further purification. Differential extraction of the [ 3 H]-peptide, digestion with S. aureus V8 protease, and high performance liquid chromatography yielded a hexapeptide with a composition consistent with the consensus sequence of the active site peptides of many serine-esterase. This and the kinetic data imply this being the mechanism of action for lipoprotein lipase

Absence of serum growth hormone binding protein in patients with growth hormone receptor deficiency (Laron dwarfism)

Energy Technology Data Exchange (ETDEWEB)

Daughaday, W.H.; Trivedi, B.

1987-07-01

It has recently been recognized that human serum contains a protein that specifically binds human growth hormone (hGH). This protein has the same restricted specificity for hGH as the membrane-bound GH receptor. To determine whether the GH-binding protein is a derivative of, or otherwise related to, the GH receptor, the authors have examined the serum of three patients with Laron-type dwarfism, a condition in which GH refractoriness has been attributed to a defect in the GH receptor. The binding of /sup 125/I-labeled hGH incubated with serum has been measured after gel filtration of the serum through an Ultrogel AcA 44 minicolumn. Results are expressed as percent of specifically bound /sup 125/I-hGH and as specific binding relative to that of a reference serum after correction is made for endogenous GH. The mean +/- SEM of specific binding of sera from eight normal adults (26-46 years of age) was 21.6 +/- 0.45%, and the relative specific binding was 101.1 +/- 8.6%. Sera from 11 normal children had lower specific binding of 12.5 +/- 1.95% and relative specific binding of 56.6 +/- 9.1%. Sera from three children with Laron-type dwarfism lacked any demonstrable GH binding, whereas sera from 10 other children with other types of nonpituitary short stature had normal relative specific binding. They suggest that the serum GH-binding protein is a soluble derivative of the GH receptor. Measurement of the serum GH-binding protein may permit recognition of other abnormalities of the GH receptor.

Absence of serum growth hormone binding protein in patients with growth hormone receptor deficiency (Laron dwarfism)

International Nuclear Information System (INIS)

Daughaday, W.H.; Trivedi, B.

1987-01-01

It has recently been recognized that human serum contains a protein that specifically binds human growth hormone (hGH). This protein has the same restricted specificity for hGH as the membrane-bound GH receptor. To determine whether the GH-binding protein is a derivative of, or otherwise related to, the GH receptor, the authors have examined the serum of three patients with Laron-type dwarfism, a condition in which GH refractoriness has been attributed to a defect in the GH receptor. The binding of 125 I-labeled hGH incubated with serum has been measured after gel filtration of the serum through an Ultrogel AcA 44 minicolumn. Results are expressed as percent of specifically bound 125 I-hGH and as specific binding relative to that of a reference serum after correction is made for endogenous GH. The mean +/- SEM of specific binding of sera from eight normal adults (26-46 years of age) was 21.6 +/- 0.45%, and the relative specific binding was 101.1 +/- 8.6%. Sera from 11 normal children had lower specific binding of 12.5 +/- 1.95% and relative specific binding of 56.6 +/- 9.1%. Sera from three children with Laron-type dwarfism lacked any demonstrable GH binding, whereas sera from 10 other children with other types of nonpituitary short stature had normal relative specific binding. They suggest that the serum GH-binding protein is a soluble derivative of the GH receptor. Measurement of the serum GH-binding protein may permit recognition of other abnormalities of the GH receptor

Autocine and Paracrine Control of Breast Cancer Growth by Sex Hormone-Binding Globulin

National Research Council Canada - National Science Library

Rosner, William

2004-01-01

We propose that the expression of Sex Hormone-Binding Globulin (SHBG) by breast cancer cells is biologically regulated and this SHBG functions to alter the effects of estrogens within the breast cancer cell...

Increased sex hormone-binding globulin levels in children and adolescents with thyrotoxicosis

DEFF Research Database (Denmark)

Nielsen, J; Jensen, Rikke Bodin Beck; Juul, Anders

2013-01-01

Thyrotoxicosis is a rare condition in pediatric patients, and optimal treatment can be difficult to achieve in some children. To our knowledge, no studies have evaluated sex hormone-binding globulin (SHBG) levels in hyperthyroid children and adolescents in relation to age- and gender...

Development of a high-throughput assay for measuring lipase activity using natural triacylglycerols coated on microtiter plates.

Science.gov (United States)

Serveau-Avesque, Carole; Verger, Robert; Rodriguez, Jorge A; Abousalham, Abdelkarim

2013-09-21

We have designed a convenient, specific, sensitive and continuous lipase assay based on the use of natural triacylglycerols (TAGs) from the Aleurites fordii seed oil which contains α-eleostearic acid (9,11,13,cis,trans,trans-octadecatrienoic acid) and which was coated in the wells of microtiter plates. The coated TAG film cannot be desorbed by the various buffers used during the lipase assay. Upon lipase action, α-eleostearic acid is liberated and desorbed from the interface and then solubilized into the micellar phase. Consequently, the UV absorbance of the α-eleostearic acid is considerably enhanced due to the transformation from an adsorbed to a water soluble state. The lipase activity can be measured continuously by recording the variations with time of the UV absorption spectra. The rate of lipolysis was monitored by measuring the increase of OD at 272 nm, which was found to be linear with time and directly proportional to the amount of added lipase. This microtiter plate lipase assay, based on coated TAGs, presents various advantages as compared to the classical systems: (i) coated TAGs on the microtiter plates could be stored for a long-time at 4 °C, (ii) higher sensitivity in lipase detection, (iii) good reproducibility, and (iv) increase of signal to noise ratio due to high UV absorption after transfer of α-eleostearic acid from an adsorbed to a soluble state. Low concentrations, down to 1 pg mL(-1) of pure Thermomyces lanuginosus or human pancreatic lipase, could be detected under standard assay conditions. The detection sensitivity of this coated method is around 1000 times higher as compared to those obtained with the classical emulsified systems. This continuous high throughput lipase assay could be used to screen new lipases and/or lipase inhibitors present in various biological samples.

Characterization of Lipoprotein Lipases interactions with Sortilin and SorLA

DEFF Research Database (Denmark)

Klinger, Stine Christensen

and regulation of both ligands, as well as to increase the understanding of SorLA’s and sortilin’s functions. Sortilin and SorLA were both shown to bind apolipoprotein A-V at the cell surface and mediate endocytosis. Apolipoprotein A-V trafficking could subsequently be followed through early endosomes, the trans-Golgi......LA might be involved in regulation or transport of brain lipoprotein lipase. In summary, this work adds new details to the current knowledge about the functions of SorLA and sortilin. Moreover, it increases our understanding of lipoprotein lipase and apolipoprotein A-V processing and regulation....

Autocrine and Paracrine Control of Breast Cancer Growth by Sex Hormone-Binding Globulin

National Research Council Canada - National Science Library

Rosner, Wiliam

2003-01-01

We propose that the expression of Sex Hormone-Binding Globulin (SHBG) by breast cancer cells is biologically regulated and that this SHBG functions to alter the effects of estrogens within the breast cancer cell...

Steroid hormones affect binding of the sigma ligand 11C-SA4503 in tumour cells and tumour-bearing rats

International Nuclear Information System (INIS)

Rybczynska, Anna A.; Elsinga, Philip H.; Sijbesma, Jurgen W.; Jong, Johan R. de; Vries, Erik F. de; Dierckx, Rudi A.; Waarde, Aren van; Ishiwata, Kiichi

2009-01-01

Sigma receptors are implicated in memory and cognitive functions, drug addiction, depression and schizophrenia. In addition, sigma receptors are strongly overexpressed in many tumours. Although the natural ligands are still unknown, steroid hormones are potential candidates. Here, we examined changes in binding of the sigma-1 agonist 11 C-SA4503 in C6 glioma cells and in living rats after modification of endogenous steroid levels. 11 C-SA4503 binding was assessed in C6 monolayers by gamma counting and in anaesthetized rats by microPET scanning. C6 cells were either repeatedly washed and incubated in steroid-free medium or exposed to five kinds of exogenous steroids (1 h or 5 min before tracer addition, respectively). Tumour-bearing male rats were repeatedly treated with pentobarbital (a condition known to result in reduction of endogenous steroid levels) or injected with progesterone. Binding of 11 C-SA4503 to C6 cells was increased (∝50%) upon removal and decreased (∝60%) upon addition of steroid hormones (rank order of potency: progesterone > allopregnanolone = testosterone = androstanolone > dehydroepiandrosterone-3-sulphate, IC 50 progesterone 33 nM). Intraperitoneally administered progesterone reduced tumour uptake and tumour-to-muscle contrast (36%). Repeated treatment of animals with pentobarbital increased the PET standardized uptake value of 11 C-SA4503 in tumour (16%) and brain (27%), whereas the kinetics of blood pool radioactivity was unaffected. The binding of 11 C-SA4503 is sensitive to steroid competition. Since not only increases but also decreases of steroid levels affect ligand binding, a considerable fraction of the sigma-1 receptor population in cultured tumour cells or tumour-bearing animals is normally occupied by endogenous steroids. (orig.)

Evaluation of inorganic matrixes as supports for immobilization of microbial lipase

Directory of Open Access Journals (Sweden)

Castro H.F.

2000-01-01

Full Text Available Candida rugosa was immobilized by physical adsorption on several inorganic supports using hexane as coupling medium. The enzymatic activities of the different derivatives were determined by both hydrolysis of olive oil and esterification of n-butanol with butyric acid. The results were compared to previous data obtained by using a controlled porous silica matrix. The goal was to contribute in searching inexpensive supports for optimum lipase performance. All supports examined exhibited good properties for binding the enzyme lipase. Zirconium phosphate was the best support, giving the highest percentage of protein fixation (86% and the highest retention of lipase activity after immobilization (34%. The operational stability performance for niobium oxide derivative was improved by previously activated the support with silane and glutaraldehyde. Thermal stabilities were also examined by thermal gravimetric analysis (TG.

Sensitivity of T-Lymphocytes to Hormones of the Anterior Pituitary Gland.

Science.gov (United States)

Tishevskaya, N V; Gevorkyan, N M; Kozlova, N I

2017-01-01

The review provides information about the features of the sensitivity of thymocytes, lymphoid organs' cells and T-lymphocytes of peripheral blood to the hormones secreted by anterior pituitary gland's cells: growth hormone, thyrotropin, adrenocorticotropic hormone, prolactin and β-endorphin. Some aspects of the T-lymphocytes's response to humoral signals from the hypophysis are shown in the article. Also the pituitary hormones' role in the regulation of proliferation, differentiation, and cytokine production of T-lymphocytes in normal and pathological conditions of the organism being discussed.

Gender and the use of hormonal contraception in women are not associated with cerebral cortical 5-HT 2A receptor binding

DEFF Research Database (Denmark)

Frokjaer, V G; Erritzoe, D; Madsen, J

2009-01-01

to frontolimbic 5-HT(2A) receptor binding and to be more pronounced in women, again, the effect of gender was not significant (P=0.42, n=127). Also, the use of hormonal contraception (n=14) within the group of pre-menopausal women (total n=29) was not associated with cortical 5-HT(2A) receptor binding (P=0.......31). In conclusion, neither gender, nor the use of hormonal contraception in premenopausal women was associated with cortical 5-HT(2A) receptor binding....... binding it is not clear if gender or use of hormonal contraception exhibits associations with 5-HT(2A) receptor binding. We found no significant effect of gender on cortical 5-HT(2A) receptor binding (P=0.15, n=132). When adjusting for the personality trait neuroticism, known to be positively correlated...

Medicinal plant phytochemicals and their inhibitory activities against pancreatic lipase: molecular docking combined with molecular dynamics simulation approach

OpenAIRE

Ahmed, Bilal; Ali Ashfaq, Usman; Mirza, Muhammad Usman

2017-01-01

Obesity is the worst health risk worldwide, which is linked to a number of diseases. Pancreatic lipase is considered as an affective cause of obesity and can be a major target for controlling the obesity. The present study was designed to find out best phytochemicals against pancreatic lipase through molecular docking combined with molecular dynamics (MD) simulation. For this purpose, a total of 3770 phytochemicals were docked against pancreatic lipase and ranked them on the basis of binding ...

Comparative performance of microbial lipases immobilized on magnetic polysiloxane polyvinyl alcohol particles

Directory of Open Access Journals (Sweden)

Laura Maria Bruno

2008-10-01

Full Text Available Microbial lipase from Mucor miehei and Candida rugosa were immobilized by covalent binding onto magnetized polysiloxane polyvinyl alcohol particles (POS-PVA. The resulting immobilized derivatives were evaluated in aqueous solution (olive oil hydrolysis and organic solvent (butyl butyrate synthesis. Higher catalytic activities were found when the coupling procedure was made with M. miehei lipase. Immobilized M. miehei lipase also showed a better operational stability and a higher half-life than C. rugosa lipase after the successive batches of esterification. The performance of C. rugosa immobilized derivative was constrained by the low lipase loading used in the immobilizing step. Further information regarding the both immobilized derivatives was also obtained through chemical composition (FTIR.Lipases microbianas de Mucor miehei e Candida rugosa foram imobilizadas por ligação covalente em partículas magnetizadas de polisiloxano-álcool polivinílico (POS-PVA. Os derivados imobilizados resultantes foram avaliados em solução aquosa (hidrólise de azeite de oliva e em solvente orgânico (síntese de butirato de butila. As maiores atividades catalíticas foram encontradas quando o procedimento de ligação foi realizado com lipase de M. miehei. O derivado imobilizado de lipase de M. miehei também apresentou melhores resultados de estabilidade operacional e tempo de meia-vida do que o de lipase de C. rugosa, após sucessivas bateladas de esterificação. O desempenho do derivado imobilizado de C. rugosa foi restringido pelo baixo carregamento de lipase usado na etapa de imobilização. Informações adicionais a respeito de ambos derivados imobilizados também foram obtidas através da composição química (FTIR.

False radioimmunoassay of thyroxine and triiodothyronine in the presence of hormone binding autoantibodies in serum

International Nuclear Information System (INIS)

Herrmann, J.; Kley, H.K.; Rudorff, K.H.; Kroell, H.J.; Krueskemper, H.L.

1976-01-01

Radioimmuno-assay of thyroxine and triiodothyronine in a 14-year-old girl with primary hypothyroidism and nodular goitre as a result of Hashimoto's thyroiditis gave falsely low values due to the presence of hormone-binding antibodies. Such antibodies occur in Hashimoto's thyroiditis and thyroid carcinoma. Their presence requires special methods for determining these hormones. (orig.) [de

pH regulation of the kinetic stability of the lipase from Thermomyces lanuginosus

DEFF Research Database (Denmark)

Wang, H.; Andersen, Kell Kleiner; Sehgal, P.

2013-01-01

Thermomyces lanuginosus lipase (TlL) is a kinetically stable protein, resistant toward both denaturation and refolding in the presence of the ionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant decyl maltoside (DecM). We investigate the pH dependence of this kinetic stability....... At pH 8, TlL remains folded and enzymatically active at multimillimolar surfactant concentrations but fails to refold from the acid urea-denatured state at submillimolar concentrations of SDS and DecM, indicating a broad concentration range of kinetic trapping or hysteresis. At pH 8, very few SDS...... molecules bind to TlL. The hysteresis SDS concentration range shrinks when moving to pH 4–6; in this pH range, SDS binds as micellelike clusters. Although hysteresis can be eliminated by reducing disulfide bonds, destabilizing the native state, and lowering the unfolding activation barrier, SDS sensitivity...

Electrochemical DNA sandwich assay with a lipase label for attomole detection of DNA

DEFF Research Database (Denmark)

Ferapontova, Elena; Hansen, Majken Nørgaard; Saunders, Aaron Marc

2010-01-01

A fast and sensitive electrochemical lipase-based sandwich hybridization assay for detection of attomole levels of DNA has been developed. A combination of magnetic beads, used for pre-concentration and bioseparation of the analyte with a lipase catalyst label allowed detection of DNA with a limi...

Relationship of dopamine type 2 receptor binding potential with fasting neuroendocrine hormones and insulin sensitivity in human obesity.

Science.gov (United States)

Dunn, Julia P; Kessler, Robert M; Feurer, Irene D; Volkow, Nora D; Patterson, Bruce W; Ansari, Mohammad S; Li, Rui; Marks-Shulman, Pamela; Abumrad, Naji N

2012-05-01

Midbrain dopamine (DA) neurons, which are involved with reward and motivation, are modulated by hormones that regulate food intake (insulin, leptin, and acyl ghrelin [AG]). We hypothesized that these hormones are associated with deficits in DA signaling in obesity. We assessed the relationships between fasting levels of insulin and leptin, and AG, BMI, and insulin sensitivity index (S(I)) with the availability of central DA type 2 receptor (D2R). We measured D2R availability using positron emission tomography and [(18)F]fallypride (radioligand that competes with endogenous DA) in lean (n = 8) and obese (n = 14) females. Fasting hormones were collected prior to scanning and S(I) was determined by modified oral glucose tolerance test. Parametric image analyses revealed associations between each metabolic measure and D2R. The most extensive findings were negative associations of AG with clusters involving the striatum and inferior temporal cortices. Regional regression analyses also found extensive negative relationships between AG and D2R in the caudate, putamen, ventral striatum (VS), amygdala, and temporal lobes. S(I) was negatively associated with D2R in the VS, while insulin was not. In the caudate, BMI and leptin were positively associated with D2R availability. The direction of associations of leptin and AG with D2R availability are consistent with their opposite effects on DA levels (decreasing and increasing, respectively). After adjusting for BMI, AG maintained a significant relationship in the VS. We hypothesize that the increased D2R availability in obese subjects reflects relatively reduced DA levels competing with the radioligand. Our findings provide evidence for an association between the neuroendocrine hormones and DA brain signaling in obese females.

Structure of the human hepatic triglyceride lipase gene

International Nuclear Information System (INIS)

Cai, Shengjian; Wong, D.M.; Chen, Sanhwan; Chan, L.

1989-01-01

The structure of the human hepatic triglyceride lipase gene was determined from multiple cosmid clones. All the exons, exon-intron junctions, and 845 bp of the 5' and 254 bp of the 3' flanking DNA were sequenced. Comparison of the exon sequences to three previously published cDNA sequences revealed differences in the sequence of the codons for residue 133, 193, 202, and 234 that may represent sequence polymorphisms. By primer extension, hepatic lipase mRNA initiates at an adenine 77 bases upstream of the translation initiation site. The hepatic lipase gene spans over 60 kb containing 9 exons and 8 introns, the latter being all located within the region encoding the mature protein. The exons are all of average size (118-234 bp). Exon 1 encodes the signal peptide, exon 4, a region that binds to the lipoprotein substrate, and exon 5, an evolutionarily highly conserved region of potential catalytic function, and exons 6 and 9 encode sequences rich in basic amino acids thought to be important in anchoring the enzyme to the endothelial surface by interacting with acidic domains of the surface glycosaminoglycans. The human lipoprotein lipase gene has been recently reported to have an identical exon-intron organization containing the analogous structural domains. The observations strongly support the common evolutionary origin of these two lipolytic enzymes

Neurokinin B and serum albumin limit copper binding to mammalian gonadotropin releasing hormone.

Science.gov (United States)

Gul, Ahmad Samir; Tran, Kevin K; Jones, Christopher E

2018-02-26

Gonadotropin releasing hormone (GnRH) triggers secretion of luteinizing hormone and follicle stimulating hormone from gonadotropic cells in the anterior pituitary gland. GnRH is able to bind copper, and both in vitro and in vivo studies have suggested that the copper-GnRH complex is more potent at triggering gonadotropin release than GnRH alone. However, it remains unclear whether copper-GnRH is the active species in vivo. To explore this we have estimated the GnRH-copper affinity and have examined whether GnRH remains copper-bound in the presence of serum albumin and the neuropeptide neurokinin B, both copper-binding proteins that GnRH will encounter in vivo. We show that GnRH has a copper dissociation constant of ∼0.9 × 10 -9  M, however serum albumin and neurokinin B can extract metal from the copper-GnRH complex. It is therefore unlikely that a copper-GnRH complex will survive transit through the pituitary portal circulation and that any effect of copper must occur outside the bloodstream in the absence of neurokinin B. Copyright © 2018 Elsevier Inc. All rights reserved.

[3H]idazoxan binding to the ovine myometrium. Binding characteristics and changes due to steroid hormones

International Nuclear Information System (INIS)

Vass-Lopez, A.; Garcia-Villar, R.; Lafontan, M.; Toutain, P.L.

1990-01-01

[3H]idazoxan binding to myometrial membranes was investigated in four groups of ewes under different steroid hormone status: control, estradiol-treated and progesterone plus estradiol-treated ovariectomized ewes and pregnant ewes. [3H]idazoxan binding to myometrial membrane fractions was saturable, reversible, specific and of high affinity. The affinity did not vary significantly between the four groups of ewes (2.8 less than KD less than 4.7 nM). Maximal binding capacity varied significantly among groups: binding of [3H]idazoxan was lower in control ovariectomized ewes than in either estradiol or progestagen plus estrogen-treated ewes (maximal binding capacity, 73 +/- 11 fmol/mg of protein vs. 108 +/- 16 and 318 +/- 65, respectively). The highest [3H]idazoxan binding was measured in pregnant ewes (maximal binding capacity, 1302 +/- 256 fmol/mg of protein). Based on the saturation studies with accurate nonspecific binding definition (phentolamine vs. epinephrine), and on the relative order of potency for selected adrenergic drugs, it could be stated that the binding sites labeled by [3H]idazoxan in our study exhibited most of the alpha-2 adrenoceptor properties. Nevertheless, these alpha-2 adrenoceptors obviously differed from the standard alpha-2A-subtype based on Ki values obtained with yohimbine and prazosin in competition studies of [3H]idazoxan binding. The increase in the number of alpha-2 adrenoceptors under progesterone domination, and especially during gestation, supported the hypothesis that this adrenoceptor subtype could play a major role in the control of the motility pattern of the ovine pregnant uterus

Specific DNA-binding proteins and DNA sequences involved in steroid hormone regulation of gene expression

International Nuclear Information System (INIS)

Spelsberg, T.; Hora, J.; Horton, M.; Goldberger, A.; Littlefield, B.; Seelke, R.; Toyoda, H.

1987-01-01

Steroid hormones circulate in the blood and are taken by target cells via complexes with intracellular binding proteins termed receptors, that are hormone and tissue specific. Each receptor binds it specific steroid with very high affinity, having an equilibrium dissociation constant (K/sub d/) in the range of 10 -9 to 10 -10 M. Once bound by their specific steroid hormones, the steroid receptors undergo a conformational change which allows them to bind with high affinity to sites on chromatin, termed nuclear acceptor sites. There are estimated 5,000 to 10,000 of these sites expressed with an equal number not expressed (''masked'') in intact chromatin. The result of the binding to nuclear acceptor sites is an alteration of gene transcription or, in some cases, gene expression as measured by the changing levels of specific RNAs and proteins in that target tissue. Each steroid regulates specific effects on the RNA and protein profiles. The chronology of the above mechanism of action after injection of radiolabelled steroid as is follows: Steroid-receptor complex formation (1 minute), nuclear acceptor sites (2 minutes), effects on RNA synthesis (10 to 30 minutes), and finally the changing protein profiles via changes in protein synthesis and protein turnover (1 to 6 hours). Thus steroid receptors represent one of the first identified intracellular gene regulation proteins. The receptor molecules themselves are regulated by the presence or absence of the steroid molecule

Alterations of serum concentrations of thyroid hormones and sex hormone-binding globulin, nuclear binding of tri-iodothyronine and thyroid hormone-stimulated cellular uptake of oxygen and glucose in mononuclear blood cells from patients with non-thyroidal illness

DEFF Research Database (Denmark)

Kvetny, J; Matzen, L

1990-01-01

Nuclear tri-iodothyronine (T3) binding and thyroid hormone-stimulated oxygen consumption and glucose uptake were examined in mononuclear blood cells from patients with non-thyroidal illness (NTI) in which serum T3 was significantly (P less than 0.05) depressed (0.62 +/- 0.12 (S.D.) nmol/l) compared...

Bacterial lipases

NARCIS (Netherlands)

Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation,

The interactions between lipase and pyridinium ligands investigated by electrochemical and spectrophotometric methods

Directory of Open Access Journals (Sweden)

Simona Patriche

2016-04-01

Full Text Available The interaction between pyridinium ligands derived from 4,4’-bipyridine (N,N’-bis(p-bromophenacyl-4,4’-bipyridinium dibromide – Lr and (N,N’-bis(p-bromophenacyl-1,2-bis (4-pyridyl ethane dibromide – Lm with lipase enzyme was evaluated. The stability of the pyridinium ligands, having an essential role in biological systems, in 0.1 M KNO3 as supporting electrolyte is influenced by the lipase concentration added. The pH and conductometry measurements in aqueous solution suggest a rapid ionic exchange process. The behavior of pyridinium ligands in the presence of lipase is investigated by cyclic voltammetry and UV/Vis spectroscopy, which indicated bindings and changes from the interaction between them. The voltammograms recorded on the glassy carbon electrode showed a more intense electronic transfer for the Lr interaction with lipase compared to Lm, which is due to the absence of mobile ethylene groups from Lr structure.

Bacterial lipases for biotechnological applications

NARCIS (Netherlands)

Jaeger, Karl-Erich; Schneidinger, Bernd; Rosenau, Frank; Werner, Michael; Lang, Dietmar; Dijkstra, Bauke W.; Schimossek, Klaus; Zonta, Albin; Reetz, Manfred T.

1997-01-01

Lipase genes originating from the Gram-negative bacteria Serrutiu marcescens and Pseudomonus urruginosa were cloned. S. marcescens lipase was overexpressed in Escherichia coli yielding inclusion bodies which were purified and finally refolded to give enzymatically active lipase. The lipase operon of

Enhanced thermostability of silica-immobilized lipase from Bacillus coagulans BTS-3 and synthesis of ethyl propionate.

Science.gov (United States)

Kumar, Satyendra; Pahujani, Shweta; Ola, R P; Kanwar, S S; Gupta, Reena

2006-06-01

A lipase from the thermophilic isolate Bacillus coagulans BTS-3 was produced and purified. The enzyme was purified 40-fold to homogeneity by ammonium sulfate precipitation and DEAE-Sepharose column chromatography. Its molecular weight was 31 kDa on SDS-PAGE. The purified lipase was immobilized on silica and its binding efficiency was found to be 60%. The enzyme took 60 min to bind maximally onto the support. The pH and temperature optima of immobilized lipase were same as those of the free enzyme, i.e. 8.5 and 55 degrees C, respectively. The immobilized enzyme had shown marked thermostability on the elevated temperatures of 55, 60, 65 and 70 degrees C. The immobilized enzyme was reused for eigth cycles as it retained almost 80% of its activity. The catalytic activity of immobilized enzyme was enhanced in n-hexane and ethanol. The immobilized enzyme when used for esterification of ethanol and propionic acid showed 96% conversion in n-hexane in 12 h at 55 degrees C.

Radiometric immunosorbent assay for the detection of anti-hormone-binding protein antibodies

International Nuclear Information System (INIS)

Pierce, E.A.; Dame, M.C.; DeLuca, H.F.

1986-01-01

A radiometric immunosorbent assay (RISA) for the detection of monoclonal antibodies to hormone-binding proteins has been developed. The assay involves incubating hybridoma supernatants in microtiter wells that have been coated with goat anti-mouse IgG antibodies. Any mouse IgG in the test supernatant is thus specifically retained in the wells. Radioactive ligand-binding protein complexes are then incubated in the wells. The presence of anti-binding protein antibodies in the supernatant is indicated by specific retention of radioactive ligand-binding protein complexes in the wells. Crude antigen preparations, such as tissue homogenates, can be used to detect antibodies. The assay is capable of detecting antibody at concentrations 20 ng/ml (approx. 100 pM IgG). The RISA has been used successfully to screen for monoclonal antibodies to the intracellular receptor for 1,25-dihydroxyvitamin D 3 and should be useful for the detection of antibodies to ligand-binding proteins in general

Glycerol Monolaurate Inhibits Lipase Production by Clinical Ocular Isolates Without Affecting Bacterial Cell Viability.

Science.gov (United States)

Flanagan, Judith Louise; Khandekar, Neeta; Zhu, Hua; Watanabe, Keizo; Markoulli, Maria; Flanagan, John Terence; Papas, Eric

2016-02-01

We sought to determine the relative lipase production of a range of ocular bacterial isolates and to assess the efficacy of glycerol monolaurate (GML) in inhibiting this lipase production in high lipase-producing bacteria without affecting bacterial cell growth. Staphylococcus aureus,Staphylococcus epidermidis,Propionibacterium acnes, and Corynebacterium spp. were inoculated at a density of 10(6)/mL in varying concentrations of GML up to 25 μg/mL for 24 hours at 37 °C with constant shaking. Bacterial suspensions were centrifuged, bacterial cell density was determined, and production of bacterial lipase was quantified using a commercial lipase assay kit. Staphylococcus spp. produced high levels of lipase activity compared with P. acnes and Corynebacterium spp. GML inhibited lipase production by Staphylococcal spp. in a dose-dependent manner, with S. epidermidis lipase production consistently more sensitive to GML than S. aureus. Glycerol monolaurate showed significant (P < 0.05) lipase inhibition above concentrations of 15 μg/mL in S. aureus and was not cytotoxic up to 25 μg/mL. For S. epidermidis, GML showed significant (P < 0.05) lipase inhibition above 7.5 μg/mL. Lipase activity varied between species and between strains. Staphylococcal spp. produced higher lipase activity compared with P. acnes and Corynebacterium spp. Glycerol monolaurate inhibited lipase production by S. aureus and S. epidermidis at concentrations that did not adversely affect bacterial cell growth. GML can be used to inhibit ocular bacterial lipase production without proving detrimental to commensal bacteria viability.

Circadian hormone profiles and insulin sensitivity in patients with Addison's disease: a comparison of continuous subcutaneous hydrocortisone infusion with conventional glucocorticoid replacement therapy.

Science.gov (United States)

Björnsdottir, Sigridur; Øksnes, Marianne; Isaksson, Magnus; Methlie, Paal; Nilsen, Roy M; Hustad, Steinar; Kämpe, Olle; Hulting, Anna-Lena; Husebye, Eystein S; Løvås, Kristian; Nyström, Thomas; Bensing, Sophie

2015-07-01

Conventional glucocorticoid replacement therapy in patients with Addison's disease (AD) is unphysiological with possible adverse effects on mortality, morbidity and quality of life. The diurnal cortisol profile can likely be restored by continuous subcutaneous hydrocortisone infusion (CSHI). The aim of this study was to compare circadian hormone rhythms and insulin sensitivity in conventional thrice-daily regimen of glucocorticoid replacement therapy with CSHI treatment in patients with AD. An open, randomized, two-period, 12-week crossover multicentre trial in Norway and Sweden. Ten Norwegian patients were admitted for 24-h sampling of hormone profiles. Fifteen Swedish patients underwent euglycaemic-hyperinsulinaemic clamp. Thrice-daily regimen of oral hydrocortisone (OHC) and CSHI treatment. We measured the circadian rhythm of cortisol, adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin-like growth factor-1, (IGF-1), IGF-binding protein-3 (IGFBP-3), glucose, insulin and triglycerides during OHC and CSHI treatment. Euglycaemic-hyperinsulinaemic clamp was used to assess insulin sensitivity. Continuous subcutaneous hydrocortisone infusion provided a more physiological circadian cortisol curve including a late-night cortisol surge. ACTH levels showed a near normal circadian variation for CSHI. CSHI prevented a continuous decrease in glucose during the night. No difference in insulin sensitivity was observed between the two treatment arms. Continuous subcutaneous hydrocortisone infusion replacement re-established a circadian cortisol rhythm and normalized the ACTH levels. Patients with CSHI replacement had a more stable night-time glucose level compared with OHC without compromising insulin sensitivity. Thus, restoring night-time cortisol levels might be advantageous for patients with AD. © 2015 John Wiley & Sons Ltd.

Lipase assay in soils by copper soap colorimetry.

Science.gov (United States)

Saisuburamaniyan, N; Krithika, L; Dileena, K P; Sivasubramanian, S; Puvanakrishnan, R

2004-07-01

A simple and sensitive method for the estimation of lipase activity in soils is reported. In this method, 50mg of soil is incubated with emulsified substrate, the fatty acids liberated are treated with cupric acetate-pyridine reagent, and the color developed is measured at 715 nm. Use of olive oil in this protocol leads to an estimation of true lipase activity in soils. The problem of released fatty acids getting adsorbed onto the soil colloids is obviated by the use of isooctane, and separate standards for different soils need not be developed. Among the various surfactants used for emulsification, polyvinyl alcohol is found to be the most effective. Incubation time of 20 min, soil concentration of 50 mg, pH 6.5, and incubation temperature of 37 degrees C were found to be the most suitable conditions for this assay. During the process of enrichment of the soils with oil, interference by the added oil is avoided by the maintenance of a suitable control, wherein 50 mg of soil is added after stopping the reaction. This assay is sensitive and it could be adopted to screen for lipase producers from enriched soils and oil-contaminated soils before resorting to isolation of the microbes by classical screening methods.

Functional diagnostics for thyrotropin hormone receptor autoantibodies: bioassays prevail over binding assays.

Science.gov (United States)

Lytton, Simon David; Schluter, Anke; Banga, Paul J

2018-06-01

Autoantibodies to the thyrotropin hormone receptor (TSH-R) are directly responsible for the hyperthyroidism in Graves' disease and mediate orbital manifestations in Graves' orbitopathy (otherwise known as thyroid eye disease). These autoantibodies are heterogeneous in their function and collectively referred to as TRAbs. Measurement of TRAbs is clinically important for diagnosis of a variety of conditions and different commercial assays with high sensitivity and specificity are available for diagnostic purposes. This review provides overwhelming evidence that the TRAbs detected in binding assays by mainly the automated electrochemical luminescence immunoassays (ECLIA) do not distinguish TRAbs that stimulate the TSH-R (called TSIs or TSAbs) and TRAbs that just inhibit the binding of TSH without stimulating the TSH-R (called TBAbs). However, TSAbs and TBAbs have divergent pathogenic roles, and depending which fraction predominates cause different clinical symptoms and engender different therapeutic regimen. Therefore, diagnostic distinction of TSAbs and TBAbs is of paramount clinical importance. To date, only bioassays such as the Mc4 TSH-R bioassay (Thyretain TM , Quidel) and the Bridge assay (Immulite 2000, Siemens) can measure TSAbs, with only the former being able to distinguish between TSAbs and TBAbs. On this note, it is strongly recommended to only use the term TSI or TSAb when reporting the results of bioassays, whereas the results of automated TRAb binding assays should be reported as TRAbs (of undetermined functional significance). This review aims to present a technical and analytical account of leading commercial diagnostic methods of anti-TSH-R antibodies, a metaanalysis of their clinical performance and a perspective for the use of cell based TSH-R bioassays in the clinical diagnostics of Graves' disease.

Analysis of Comparative Sequence and Genomic Data to Verify Phylogenetic Relationship and Explore a New Subfamily of Bacterial Lipases.

Directory of Open Access Journals (Sweden)

Malihe Masomian

Full Text Available Thermostable and organic solvent-tolerant enzymes have significant potential in a wide range of synthetic reactions in industry due to their inherent stability at high temperatures and their ability to endure harsh organic solvents. In this study, a novel gene encoding a true lipase was isolated by construction of a genomic DNA library of thermophilic Aneurinibacillus thermoaerophilus strain HZ into Escherichia coli plasmid vector. Sequence analysis revealed that HZ lipase had 62% identity to putative lipase from Bacillus pseudomycoides. The closely characterized lipases to the HZ lipase gene are from thermostable Bacillus and Geobacillus lipases belonging to the subfamily I.5 with ≤ 57% identity. The amino acid sequence analysis of HZ lipase determined a conserved pentapeptide containing the active serine, GHSMG and a Ca(2+-binding motif, GCYGSD in the enzyme. Protein structure modeling showed that HZ lipase consisted of an α/β hydrolase fold and a lid domain. Protein sequence alignment, conserved regions analysis, clustal distance matrix and amino acid composition illustrated differences between HZ lipase and other thermostable lipases. Phylogenetic analysis revealed that this lipase represented a new subfamily of family I of bacterial true lipases, classified as family I.9. The HZ lipase was expressed under promoter Plac using IPTG and was characterized. The recombinant enzyme showed optimal activity at 65 °C and retained ≥ 97% activity after incubation at 50 °C for 1h. The HZ lipase was stable in various polar and non-polar organic solvents.

Hormone response element binding proteins: novel regulators of vitamin D and estrogen signaling.

Science.gov (United States)

Lisse, Thomas S; Hewison, Martin; Adams, John S

2011-03-01

Insights from vitamin D-resistant New World primates and their human homologues as models of natural and pathological insensitivity to sterol/steroid action have uncovered a family of novel intracellular vitamin D and estrogen regulatory proteins involved in hormone action. The proteins, known as "vitamin D or estrogen response element-binding proteins", behave as potent cis-acting, transdominant regulators to inhibit steroid receptor binding to DNA response elements and is responsible for vitamin D and estrogen resistances. This set of interactors belongs to the heterogeneous nuclear ribonucleoprotein (hnRNP) family of previously known pre-mRNA-interacting proteins. This review provides new insights into the mechanism by which these novel regulators of signaling and metabolism can act to regulate responses to vitamin D and estrogen. In addition the review also describes other molecules that are known to influence nuclear receptor signaling through interaction with hormone response elements. Copyright © 2011 Elsevier Inc. All rights reserved.

Binding specificity of the juvenile hormone carrier protein from the hemolymph of the tobacco hornworm Manduca sexta Johannson (Lepidoptera: Sphingidae).

Science.gov (United States)

Peterson, R C; Reich, M F; Dunn, P E; Law, J H; Katzenellnbogen, J A

1977-05-17

A series of analogues of insect juvenile hormone (four geometric isomers of methyl epoxyfarnesenate, several para-substituted epoxygeranyl phenyl ethers, and epoxyfarnesol and its acetate and haloacetate derivatives) was prepared to investigate the binding specificity of the hemolymph juvenile hormone binding protein from the tobacco hornworm Manduct sexta. The relative binding affinities were determined by a competition assay against radiolabeled methyl (E,E)-3,11-dimethyl-7-ethyl-cis-10,11-epoxytrideca-2,6-dienoate (JH I). The ratio of dissociation constants was estimated by plotting competitor data according to a linear transformation of the dissociation equations describing competition of two ligands for a binding protein. The importance of the geometry of the sesquiterpene hydrocarbon chain is indicated by the fact that the binding affinity is decreased as Z (cis) double bonds are substituted for E (trans) double bonds in the methyl epoxyfarnesenate series; the unepoxidized analogues do not bind. A carboxylic ester function is important although its orientation can be reversed, as indicated by the good binding of epoxyfarnesyl acetate. In the monoterpene series, methyl epoxygeranoate shows no affinity for the binding protein, but substitution of a phenyl or p-carbomethoxyphenyl ether for the ester function imparts a low, but significant affinity. These data taken together with earlier results indicate that the binding site for juvenile hormone in the hemolymph binding protein is characterized by a sterically defined hydrophobic region with polar sites that recognize the epoxide and the ester functions.

Steroid hormones affect binding of the sigma ligand {sup 11}C-SA4503 in tumour cells and tumour-bearing rats

Energy Technology Data Exchange (ETDEWEB)

Rybczynska, Anna A.; Elsinga, Philip H.; Sijbesma, Jurgen W.; Jong, Johan R. de; Vries, Erik F. de; Dierckx, Rudi A.; Waarde, Aren van [University of Groningen, Nuclear Medicine and Molecular Imaging, University of Groningen Medical Center, Groningen (Netherlands); Ishiwata, Kiichi [Tokyo Metropolitan Institute of Gerontology, Positron Medical Center, Tokyo (Japan)

2009-07-15

Sigma receptors are implicated in memory and cognitive functions, drug addiction, depression and schizophrenia. In addition, sigma receptors are strongly overexpressed in many tumours. Although the natural ligands are still unknown, steroid hormones are potential candidates. Here, we examined changes in binding of the sigma-1 agonist {sup 11}C-SA4503 in C6 glioma cells and in living rats after modification of endogenous steroid levels. {sup 11}C-SA4503 binding was assessed in C6 monolayers by gamma counting and in anaesthetized rats by microPET scanning. C6 cells were either repeatedly washed and incubated in steroid-free medium or exposed to five kinds of exogenous steroids (1 h or 5 min before tracer addition, respectively). Tumour-bearing male rats were repeatedly treated with pentobarbital (a condition known to result in reduction of endogenous steroid levels) or injected with progesterone. Binding of {sup 11}C-SA4503 to C6 cells was increased ({proportional_to}50%) upon removal and decreased ({proportional_to}60%) upon addition of steroid hormones (rank order of potency: progesterone > allopregnanolone = testosterone = androstanolone > dehydroepiandrosterone-3-sulphate, IC{sub 50} progesterone 33 nM). Intraperitoneally administered progesterone reduced tumour uptake and tumour-to-muscle contrast (36%). Repeated treatment of animals with pentobarbital increased the PET standardized uptake value of {sup 11}C-SA4503 in tumour (16%) and brain (27%), whereas the kinetics of blood pool radioactivity was unaffected. The binding of {sup 11}C-SA4503 is sensitive to steroid competition. Since not only increases but also decreases of steroid levels affect ligand binding, a considerable fraction of the sigma-1 receptor population in cultured tumour cells or tumour-bearing animals is normally occupied by endogenous steroids. (orig.)

Lipases in green chemistry: acylation and alcoholysis on steroids and nucleosides.

Science.gov (United States)

Baldessari, Alicia; Iglesias, Luis E

2012-01-01

In this article, we describe the application of lipases in acylation and alcoholysis reactions on steroids and nucleosides. In the field of steroids, a variety of acetyl and fatty acid derivatives of androstanes, pregnanes, and cholestanes have been prepared through lipase-catalyzed acylation and alcoholysis reactions taking advantage of the high regio- and stereoselectivity of these enzymes. The substrates as well as the products show a high degree of biological activity as neurosteroids, hormones, and glucocorticoids. The regioselective preparation of diacylated nucleosides by means of an enzymatic alcoholysis allowed the synthesis of nucleosides prodrugs or modified nucleosides. The quantitative full deacylation and dealkoxycarbonylation of nucleosides and steroids is a mild synthetic method for the deprotection of these labile compounds. Some of the reported steroid and nucleoside products are novel, and it is not possible to obtain them satisfactorily by following traditional synthetic procedures. The advantages presented by this methodology, such as selectivity, mild reaction conditions, and low environmental impact, make the lipases an important tool in the application of the principles of Green Chemistry, offering a convenient way to prepare derivatives of natural compounds with a great potential in the pharmaceutical industry.

Regulation of hepatic level of fatty-acid-binding protein by hormones and clofibric acid in the rat.

Science.gov (United States)

Nakagawa, S; Kawashima, Y; Hirose, A; Kozuka, H

1994-01-01

Regulation of the hepatic level of fatty-acid-binding protein (FABP) by hormones and p-chlorophenoxyisobutyric acid (clofibric acid) was studied. The hepatic level of FABP, measured as the oleic acid-binding capacity of the cytosolic FABP fraction, was decreased in streptozotocin-diabetic rats. The level of FABP was markedly increased in adrenalectomized rats, and the elevation was prevented by the administration of dexamethasone. Hypothyroidism decreased the level of FABP and hyperthyroidism increased it. A high correlation between the incorporation of [14C]oleic acid in vivo into hepatic triacylglycerol and the level of FABP was found for normal, diabetic and adrenalectomized rats. The level of FABP was increased by administration of clofibric acid to rats in any altered hormonal states, as was microsomal 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, a peroxisome-proliferator-responsive parameter. These results suggest that the hepatic level of FABP is under regulation by multiple hormones and that clofibric acid induces FABP and 1-acyl-GPC acyltransferase by a mechanism which may be distinct from that by which hormones regulate the level of FABP. PMID:8110197

Lignans from the roots of Urtica dioica and their metabolites bind to human sex hormone binding globulin (SHBG).

Science.gov (United States)

Schöttner, M; Gansser, D; Spiteller, G

1997-12-01

Polar extracts of the stinging nettle (Urtica dioica L.) roots contain the ligans (+)-neoolivil, (-)-secoisolariciresinol, dehydrodiconiferyl alcohol, isolariciresinol, pinoresinol, and 3,4-divanillyltetrahydrofuran. These compounds were either isolated from Urtica roots, or obtained semisynthetically. Their affinity to human sex hormone binding globulin (SHBG) was tested in an in vitro assay. In addition, the main intestinal transformation products of plant lignans in humans, enterodiol and enterolactone, together with enterofuran were checked for their activity. All lignans except (-)-pinoresinol developed a binding affinity to SHBG in the in vitro assay. The affinity of (-)-3,4-divanillyltetrahydrofuran was outstandingly high. These findings are discussed with respect to potential beneficial effects of plant lignans on benign prostatic hyperplasia (BPH).

Hormonal regulation of lipid metabolism in developing coho salmon, Oncorhynchus kisutch

International Nuclear Information System (INIS)

Sheridan, M.A.

1985-01-01

Lipid metabolism in juvenile coho salmon is characterized, and adaptive changes in lipid mobilization are described in relation to development and hormonal influences. The rates of lipogenesis and lipolysis were determined in selected tissues of juvenile salmon during the period of seawater preadaptive development (smoltification). Neutral lipid (sterol) and fatty acid synthesis in the liver and mesenteric fat was measured by tritium incorporation. Fatty acid synthesis in the liver and mesenteric fat decreased by 88% and 81%, respectively, between late February (parr) and early June (smolt). To assess the role of hormones in smoltification-associated lipid depletion, growth hormone, prolactin, thyroxin and cortisol were administered in vivo early in development (parr) to determine if any of these factors could initiate the metabolic responses normally seen later in development (smolt). Growth hormone stimulated lipid mobilization from coho salmon parr. Prolactin strongly stimulated lipid mobilization in coho parr. Thyroxin and cortisol also stimulated lipid mobilization for coho salmon parr. The direct effect of hormones was studied by in vitro pH-stat incubation of liver slices. These data suggest that norepinephrine stimulates fatty acid release via β-adrenergic pathways. Somatostatin and its partial analogue from the fish caudal neurosecretory system, urotensin II, also affect lipid mobilization. These results establish the presence of hormone-sensitive lipase in salmon liver and suggest that the regulation of lipid metabolism in salmon involves both long-acting and short-acting hormonal agents

Disruption of thyroid hormone binding to sea bream recombinant transthyretin by ioxinyl and polybrominated diphenyl ethers.

Science.gov (United States)

Morgado, Isabel; Hamers, Timo; Van der Ven, Leo; Power, D M

2007-08-01

A number of chemicals released into the environment share structural similarity to the thyroid hormones (THs), thyroxine (T(4)) and triiodothyronine (T(3)) and it is thought that they may interfere with the thyroid axis and behave as endocrine disruptors (EDs). One of the ways by which such environmental contaminants may disrupt the TH axis is by binding to TH transporter proteins. Transthyretin (TTR) is one of the thyroid hormone binding proteins responsible for TH transport in the blood. TTR forms a stable tetramer that binds both T(4) and T(3) and in fish it is principally synthesized in the liver but is also produced by the brain and intestine. In the present study, we investigate the ability of some chemicals arising from pharmaceutical, industrial or agricultural production and classified as EDs, to compete with [I(125)]-T(3) for sea bream recombinant TTR (sbrTTR). Ioxinyl, a common herbicide and several polybrominated diphenyl ethers were strong inhibitors of [I(125)]-T(3) binding to TTR and some showed even greater affinity than the natural ligand T(3). The TTR competitive binding assay developed offers a quick and effective tool for preliminary risk assessment of chemicals which may disrupt the thyroid axis in teleost fish inhabiting vulnerable aquatic environments.

Acid Lipase Disease

Science.gov (United States)

... of Neurological Disorders and Stroke conducts and supports research to understand lipid storage diseases such as acid lipase deficiency and ... of Neurological Disorders and Stroke conducts and supports research to understand lipid storage diseases such as acid lipase deficiency and ...

Effects of methanol on lipases: molecular, kinetic and process issues in the production of biodiesel.

Science.gov (United States)

Lotti, Marina; Pleiss, Jürgen; Valero, Francisco; Ferrer, Pau

2015-01-01

The biotechnological production of biodiesel is based on transesterification/esterification reactions between a source of fatty acids and a short-chain alcohol, usually methanol, catalysed by enzymes belonging to the class known as lipases. Several lipases used in industrial processes, although stable in the presence of other organic solvents, are inactivated by methanol at or below the concentration optimal for biodiesel production, making it necessary to use stepwise methanol feeding or pre-treatment of the enzyme. In this review article we focus on what is currently know about methanol inactivation of lipases, a phenomenon which is not common to all lipase enzymes, with the goal of improving the biocatalytic process. We suggest that different mechanisms can lead to inactivation of different lipases, in particular substrate inhibition and protein unfolding. Attempts to improve the performances of methanol sensitive lipases by mutagenesis as well as process engineering approaches are also summarized. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Research resource: novel structural insights bridge gaps in glycoprotein hormone receptor analyses.

Science.gov (United States)

Kreuchwig, Annika; Kleinau, Gunnar; Krause, Gerd

2013-08-01

The first version of a glycoprotein hormone receptor (GPHR) information resource was designed to link functional with structural GPHR information, in order to support sequence-structure-function analysis of the LH, FSH, and TSH receptors (http://ssfa-gphr.de). However, structural information on a binding- and signaling-sensitive extracellular fragment (∼100 residues), the hinge region, had been lacking. A new FSHR crystal structure of the hormone-bound extracellular domain has recently been solved. The structure comprises the leucine-rich repeat domain and most parts of the hinge region. We have not only integrated the new FSHR/FSH structure and the derived homology models of TSHR/TSH, LHCGR/CG, and LHCGR/LH into our web-based information resource, but have additionally provided novel tools to analyze the advanced structural features, with the common characteristics and distinctions between GPHRs, in a more precise manner. The hinge region with its second hormone-binding site allows us to assign functional data to the new structural features between hormone and receptor, such as binding details of a sulfated tyrosine (conserved throughout the GPHRs) extending into a pocket of the hormone. We have also implemented a protein interface analysis tool that enables the identification and visualization of extracellular contact points between interaction partners. This provides a starting point for comparing the binding patterns of GPHRs. Together with the mutagenesis data stored in the database, this will help to decipher the essential residues for ligand recognition and the molecular mechanisms of signal transduction, extending from the extracellular hormone-binding site toward the intracellular G protein-binding sites.

Simultaneous measurement of hormone release and secretagogue binding by individual pituitary cells

International Nuclear Information System (INIS)

Smith, P.F.; Neill, J.D.

1987-01-01

The quantitative relationship between receptor binding and hormone secretion at the single-cell level was investigated in the present study by combining a reverse hemolytic plaque assay for measurement of luteinizing hormone (LH) secretion from individual pituitary cells with an autoradiographic assay of 125 I-labeled gonadontropin-releasing hormone (GnRH) agonist binding to the same cells. In the plaque assay, LH secretion induces complement-mediated lysis of the LH-antibody-coated erythrocytes around the gonadotropes, resulting in areas of lysis (plaques). LH release from individual gonadotropes was quantified by comparing radioimmunoassayable LH release to hemolytic area in similarly treated cohort groups of cells; plaque area was linearly related to the amount of LH secreted. Receptor autoradiography was performed using 125 I-labeled GnRH-A (a superagonist analog of GnRH) both as the ligand and as the stimulant for LH release in the plaque assay. The grains appeared to represent specific and high-affinity receptors for GnRH because (i) no pituitary cells other than gonadotropes bound the labeled ligand and (ii) grain development was progressively inhibited by coincubation with increasing doses of unlabeled GnRH-A. The authors conclude that GnRH receptor number for any individual gonadotrope is a weak determinant of the amount of LH it can secrete; nevertheless, full occupancy of all its GnRH receptors is required for any gonadotrope to reach its full LH-secretory capacity. Apparently the levels of other factors comprising the steps along the secretory pathway determine the secretory capacity of an individual cell

The Effect of Tallow As Lipase Inducer on Total of Aspergillus Niger, Lipolitic Activity and Lipase Yield

Directory of Open Access Journals (Sweden)

Manik Eirry Sawitri

2012-02-01

Full Text Available The objectives of this research was to determined of tallow addition with different concentration as lipase Aspergillus niger inducer to total of A. niger, lipolitic activity and lipase yield. The result showed that tallow addition as inducer in the lipase A. niger production gave no significant effect on total of A. niger (5.3 x 107 – 1.7 x 108 cfu/gram in the medium. Tallow addition gave a highly significant effect on lipolytic activity and yield of lipase A. niger. Lipolytic activity ranged between 32.0354 – 53.1197 U/mg protein, while the yield of lipase was 6.6418–7.8941 µg/ml. The conclusion of this research was the addition of tallow for 8% as the lipase inducer of A. niger on lipase production was  more effective to obtain the optimal result. Keywords : Tallow, lipase, inducer, Aspergillus niger

Changes in serum concentrations of growth hormone, insulin, insulin-like growth factor and insulin-like growth factor-binding proteins 1 and 3 and urinary growth hormone excretion during the menstrual cycle

DEFF Research Database (Denmark)

Juul, A; Scheike, Thomas Harder; Pedersen, A T

1997-01-01

Few studies exist on the physiological changes in the concentrations of growth hormone (GH), insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) within the menstrual cycle, and some controversy remains. We therefore decided to study the impact of endogenous sex steroids on the GH......-IGF-IGFBP axis during the ovulatory menstrual cycle in 10 healthy women (aged 18-40 years). Blood sampling and urinary collection was performed every morning at 0800 h for 32 consecutive days. Every second day the subjects were fasted overnight before blood sampling. Follicle stimulating hormone, luteinizing...... hormone (LH), oestradiol, progesterone, IGF-I, IGFBP-3, sex hormone-binding globulin, dihydroepiandrosterone sulphate and GH were determined in all samples, whereas insulin and IGFBP-1 were determined in fasted samples only. Serum IGF-I concentrations showed some fluctuation during the menstrual cycle...

Small-scale extraction and radioiodination of human hormones for the substitution of imported radioimmunoassay reagents

International Nuclear Information System (INIS)

Gimbo, E.K.; Ribela, M.T.C.P.; Borghi, V.C.; Schwarz, I.; Morganti, L.; Araujo, E.A.; Bartolini, P.

1988-01-01

The methods for national production of radioimmunoassay reagents to substitute imported kits of: highly purified unlabelled hormones for radioiodination; 125 I-labelled hormones; and specific high titre antisera are presented. The extraction and purification of human growth hormone (hGH) and human luteinizing hormone (hGH) were done from human pituitaries. The 125 I-labelled hormones are obtained by stoichiometric methods. The 125 I-hGH, 125 I-hLH, I-hTSH and 125 I- h calcitonin were prepared and tested in internal and external quality control, in comparison with imported products. The parameters such as: maximum binding to specific antiserum (Bo), nonspecific binding (NSB), mean effective dose (ED 50), sensitivity and accuracy were evaluated. (M.C.K.) [pt

Molecular conformation, receptor binding, and hormone action of natural and synthetic estrogens and antiestrogens.

Science.gov (United States)

Duax, W L; Griffin, J F; Weeks, C M; Korach, K S

1985-01-01

The X-ray crystallographic structural determinations of synthetic estrogens and antiestrogens provide reliable information on the global minimum energy conformation of these molecules or a local minimum energy conformation that is within 1 or 2 kcal/mole of the global minimum. In favorable cases, state-of-the-art molecular mechanics calculations provide quantitative agreement with X-ray results and information on the relative energy of other local minimum energy conformations not observed crystallographically. Because the conformation of diethylstilbestrol (DES) observed in solvated crystals has an overall conformation and dipole moment more similar to estradiol it is the form more likely to bind to the receptor and produce hormone activity. Either phenol ring of DES can successfully mimic the estradiol A-ring in binding to the receptor. Indenestrol A (INDA) and indenestrol B (INDB) have nearly identical fully extended planar conformations. Either the alpha or gamma rings of these compounds may mimic the A ring of estradiol and compete for the estrogen receptor. Although there are eight distinct ways in which molecules of a racemic mixture of INDA or INDB can bind to the receptor, not all of them may be able to elicit a hormonal response. This may account for the reduced biological activity of the compounds despite their successful competition for receptor binding. The minimum energy conformations of Z-pseudodiethylstilbestrol (ZPD) and E-pseudodiethylstilbestrol (EPD) are bent in a fashion similar to that of indanestrol (INDC). These molecules have good binding affinity suggesting that the receptor does not require a flat molecule. Therefore these conformations would appear to be compatible with receptor binding, but only the Z isomer has an energetically allowed extended conformation that accounts for its observed biological activity relative to DES. PMID:3905370

Lipase H, a new member of the triglyceride lipase family synthesized by the intestine

NARCIS (Netherlands)

Jin, Weijun; Broedl, Uli C.; Monajemi, Houshang; Glick, Jane M.; Rader, Daniel J.

2002-01-01

We report here the molecular cloning of a novel member of the triglyceride lipase family, a 2.4-kb cDNA encoding human lipase H (LIPH) and the mouse ortholog (Liph). The human LIPH cDNA encodes a 451-amino-acid protein with a lipase domain. Mouse Liph shows 85% amino acid identity and 75% nucleotide

Comparison of immunoreactive serum trypsinogen and lipase in Cystic Fibrosis

International Nuclear Information System (INIS)

Lloyd-Still, J.D.; Weiss, S.; Wessel, H.; Fong, L.; Conway, J.J.

1984-01-01

The incidence of Cystic Fibrosis (CF) is 1 in 2,000. Early detection and treatment of CF may necessitate newborn screening with a reliable and cost-effective test. Serum immunoreactive trypsinogen (IRT) an enzyme produced by the pancreas, is detectable by radioimmunoassay (RIA) techniques. Recently, it has been shown that IRT is elevated in CF infants for the first few months of life and levels become subnormal as pancreatic insufficiency progresses. Other enzymes produced by the pancreas, such as lipase, are also elevated during this time. The author's earlier work confirmed previous reports of elevated IRT levels in CF infants. The development of a new RIA for lipase (nuclipase) has enabled comparison of these 2 pancreatic enzymes in C.F. Serum IRT and lipase determinations were performed on 2 groups of CF patients; infants under 1 year of age, and children between 1 and 18 years of age. Control populations of the same age groups were included. The results showed that both trypsin (161 +- 92 ng/ml, range 20 to 400) and lipase (167 +- 151 ng/ml, range 29 to 500) are elevated in CF in the majority of infants. Control infants had values of IRT ranging from 20 to 29.5 ng/ml and lipase values ranging from 23 to 34 ng/ml. IRT becomes subnormal in most CF patients by 8 years of age as pancreatic function insufficiency increases. Lipase levels and IRT levels correlate well in infancy, but IRT is a more sensitive indicator of pancreatic insufficiency in older patients with CF

Increased insulin sensitivity in intrauterine growth retarded newborns--do thyroid hormones play a role?

Science.gov (United States)

Setia, Sajita; Sridhar, M G; Koner, B C; Bobby, Zachariah; Bhat, Vishnu; Chaturvedula, Lata

2007-02-01

Thyroid hormones are necessary for normal brain development. We studied thyroid hormone profile and insulin sensitivity in intrauterine growth retarded (IUGR) newborns to find correlation between insulin sensitivity and thyroid status in IUGR newborns. Fifty IUGR and fifty healthy control infants were studied at birth. Cord blood was collected for determination of T(3), T(4), TSH, glucose and insulin levels. IUGR newborns had significantly lower insulin, mean+/-S.D., 5.25+/-2.81 vs. 11.02+/-1.85microU/ml, but significantly higher insulin sensitivity measured as glucose to insulin ratio (G/I), 9.80+/-2.91 vs. 6.93+/-1.08 compared to healthy newborns. TSH was also significantly higher 6.0+/-2.70 vs. 2.99+/-1.05microU/ml with significantly lower T(4), 8.65+/-1.95 vs. 9.77+/-2.18microg/dl, but similar T(3) levels, 100.8+/-24.36 vs. 101.45+/-23.45ng/dl. On stepwise linear regression analysis in IUGR infants, insulin sensitivity was found to have a significant negative association with T(4) and significant positive association with TSH. Thyroid hormones may play a role in increased insulin sensitivity at birth in IUGR.

Comparative genomic analysis of the Lipase3 gene family in five plant species reveals distinct evolutionary origins.

Science.gov (United States)

Wang, Dan; Zhang, Lin; Hu, JunFeng; Gao, Dianshuai; Liu, Xin; Sha, Yan

2018-04-01

Lipases are physiologically important and ubiquitous enzymes that share a conserved domain and are classified into eight different families based on their amino acid sequences and fundamental biological properties. The Lipase3 family of lipases was reported to possess a canonical fold typical of α/β hydrolases and a typical catalytic triad, suggesting a distinct evolutionary origin for this family. Genes in the Lipase3 family do not have the same functions, but maintain the conserved Lipase3 domain. There have been extensive studies of Lipase3 structures and functions, but little is known about their evolutionary histories. In this study, all lipases within five plant species were identified, and their phylogenetic relationships and genetic properties were analyzed and used to group them into distinct evolutionary families. Each identified lipase family contained at least one dicot and monocot Lipase3 protein, indicating that the gene family was established before the split of dicots and monocots. Similar intron/exon numbers and predicted protein sequence lengths were found within individual groups. Twenty-four tandem Lipase3 gene duplications were identified, implying that the distinctive function of Lipase3 genes appears to be a consequence of translocation and neofunctionalization after gene duplication. The functional genes EDS1, PAD4, and SAG101 that are reportedly involved in pathogen response were all located in the same group. The nucleotide diversity (Dxy) and the ratio of nonsynonymous to synonymous nucleotide substitutions rates (Ka/Ks) of the three genes were significantly greater than the average across the genomes. We further observed evidence for selection maintaining diversity on three genes in the Toll-Interleukin-1 receptor type of nucleotide binding/leucine-rich repeat immune receptor (TIR-NBS LRR) immunity-response signaling pathway, indicating that they could be vulnerable to pathogen effectors.

Activity and stability of immobilized lipases in lipase-catalyzed modification of peanut oil

OpenAIRE

Soumanou Mohamed M.; Edorh Aleodjrodo P.; Bornscheuer Uwe T.

2004-01-01

Fatty acid release during lipolysis of peanut oil using microbial free and immobilized lipases in aqueous media was developed. Immobilized lipase from Rhizomucor miehei (RML) gave the best result from its ability to clive different fatty acids from peanut oil in such media. In organic solvent, interesterification of peanut oil with tricaprylin using immobilized lipases from RML, Chromobacterium viscosum (CVL) and Candida rugosa (CRL) was performed. The best substrate molar ratio of tricapryli...

Biodiesel production with immobilized lipase: A review.

Science.gov (United States)

Tan, Tianwei; Lu, Jike; Nie, Kaili; Deng, Li; Wang, Fang

2010-01-01

Fatty acid alkyl esters, also called biodiesel, are environmentally friendly and show great potential as an alternative liquid fuel. Biodiesel is produced by transesterification of oils or fats with chemical catalysts or lipase. Immobilized lipase as the biocatalyst draws high attention because that process is "greener". This article reviews the current status of biodiesel production with immobilized lipase, including various lipases, immobilization methods, various feedstocks, lipase inactivation caused by short chain alcohols and large scale industrialization. Adsorption is still the most widely employed method for lipase immobilization. There are two kinds of lipase used most frequently especially for large scale industrialization. One is Candida antartica lipase immobilized on acrylic resin, and the other is Candida sp. 99-125 lipase immobilized on inexpensive textile membranes. However, to further reduce the cost of biodiesel production, new immobilization techniques with higher activity and stability still need to be explored. Copyright 2010 Elsevier Inc. All rights reserved.

Fatty acids bind tightly to the N-terminal domain of angiopoietin-like protein 4 and modulate its interaction with lipoprotein lipase.

Science.gov (United States)

Robal, Terje; Larsson, Mikael; Martin, Miina; Olivecrona, Gunilla; Lookene, Aivar

2012-08-24

Angiopoietin-like protein 4 (Angptl4), a potent regulator of plasma triglyceride metabolism, binds to lipoprotein lipase (LPL) through its N-terminal coiled-coil domain (ccd-Angptl4) inducing dissociation of the dimeric enzyme to inactive monomers. In this study, we demonstrate that fatty acids reduce the inactivation of LPL by Angptl4. This was the case both with ccd-Angptl4 and full-length Angptl4, and the effect was seen in human plasma or in the presence of albumin. The effect decreased in the sequence oleic acid > palmitic acid > myristic acid > linoleic acid > linolenic acid. Surface plasmon resonance, isothermal titration calorimetry, fluorescence, and chromatography measurements revealed that fatty acids bind with high affinity to ccd-Angptl4. The interactions were characterized by fast association and slow dissociation rates, indicating formation of stable complexes. The highest affinity for ccd-Angptl4 was detected for oleic acid with a subnanomolar equilibrium dissociation constant (K(d)). The K(d) values for palmitic and myristic acid were in the nanomolar range. Linoleic and linolenic acid bound with much lower affinity. On binding of fatty acids, ccd-Angptl4 underwent conformational changes resulting in a decreased helical content, weakened structural stability, dissociation of oligomers, and altered fluorescence properties of the Trp-38 residue that is located close to the putative LPL-binding region. Based on these results, we propose that fatty acids play an important role in modulating the effects of Angptl4.

Organic Solvent Tolerant Lipases and Applications

Directory of Open Access Journals (Sweden)

Shivika Sharma

2014-01-01

Full Text Available Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s could be performed in water-restricted organic media as organic solvent(s not only improve(s the solubility of substrate and reactant in reaction mixture but also permit(s the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

Determinação das propriedades catalíticas em meio aquoso e orgânico da lipase de Candida rugosa imobilizada em celulignina quimicamente modificada por carbonildiimidazol Assessment of catalytic properties in aqueous and organic media of lipase from Candida rugosa immobilized on wood cellulignin activated with carbonyldiimidazole

Directory of Open Access Journals (Sweden)

Fabrício M. Gomes

2006-07-01

Full Text Available Microbial lipase from Candida rugosa was immobilized by covalent binding on wood cellulignin (Eucaliptus grandis chemically modified with carbonyldiimidazole. The immobilized system was fully evaluated in aqueous (olive oil hydrolysis and organic (ester synthesis media. A comparative study between free and immobilized lipase was carried out in terms of pH, temperature and thermal stability. A higher pH value (8.0 was found optimal for the immobilized lipase. The optimal reaction temperature shifted from 37 °C for the free lipase to 45 °C for the immobilized lipase. The pattern of heat stability indicated that the immobilization process tends to stabilize the enzyme. Kinetics tests at 37 °C following the hydrolysis of olive oil obeyed the Michaelis-Menten rate equation. Values for Km = 924.9 mM and Vmax = 198.3 U/mg were lower than for free lipase, suggesting that the affinity towards the substrate changed and the activity of the immobilized lipase decreased during the course of immobilization. The immobilized derivative was also tested in the ester synthesis from several alcohols and carboxylic acids.

FRAKSINASI ENZIM LIPASE DARI ENDOSPERM KELAPA DENGAN METODE SALTING OUT (Lipase fractionation of Coconut Endosperm by Salting out Method

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Moh. Su'i

2014-02-01

Full Text Available This research learns about fractionation of lipases activity from coconut endosperm by using ammonium sulphate of 0–15%; 15-30 %, 30–45 %, 45–60 %, 60–75 % and 75–90 %. The results showed that the fractions of 0–15% ; 30–45 %, 45–60 % and 60–75 % have lipase activity. Meanwhile, the highest activity was fractions of 60-75%. fractions of 15-30% and 75-90%  have no lipase enzym activity. Molecule weigh of lipase enzyme was 72 kDa. Keywords: Lipases, endosperm, coconut, fractionation, ammonium sulphate   ABSTRAK Penelitian ini mempelajari fraksinasi enzim lipase dari endosperm kelapa menggunakan ammonium sulfat. fraksinasi dilakukan dengan variasi konsentrasi ammonium sulfat 0–15% ; 15-30%; 30–45 %, 45–60 %, 60–75 % dan 75–90 %. Hasil penelitian menunjukkan bahwa enzim lipase terdapat pada fraksi 0–15% ; 30–45 %, 45–60 % dan fraksi 60–75 % dengan aktivitas enzim tertinggi pada fraksi 60-75%. Sedangkan fraksi 15-30% dan 75-90% tidak ada enzim lipase. Berat molekul enzim lipase pada semua fraksi 72 kDa. Kata kunci: Lipase, endosperm, fraksinasi, ammonium sulfat

Radioimmunoassay of testosterone and of sexual hormone-binding globulin in plasma of women with hirsutism

International Nuclear Information System (INIS)

Warenik-Szymankiewicz, A.; Baron, J.; Chawlisz, K.

1980-01-01

Plasma-borne testosterone was determined in 176 women with hirsutism, and in 47 patients sexual hormone-binding globulin was determined as well. The highest average testosterone values were recorded from cases with congenital adrenogenital syndrome (AGS). In cases of postnatal AGS values were much lower, but they were clearly in excess of those recordable from Stein-Leventhal syndrome. Plasma borne testosterone in cases of hirsutism came very close to testosterone levels established in the context of Stein-Leventhal syndrome. Testosterone levels dropped with significance, following AGS treatment, using cortisol derivatives, and following wedge-shaped ovariectomy. Sexual hormone binding-globulin was found to be strongly reduced in almost all women with hirsutism. Such reduction seemed to suggest the presence of increased amounts of free active testosterone in the blood of those patients. Determination of plasma-borne testosterone in cases of hirsutism is considered to be essential to both diagnosis of the endocrinological syndromes and monitoring of therapy. (author)

Capacity for cooperative binding of thyroid hormone (T3) receptor dimers defines wild type T3 response elements.

Science.gov (United States)

Brent, G A; Williams, G R; Harney, J W; Forman, B M; Samuels, H H; Moore, D D; Larsen, P R

1992-04-01

Thyroid hormone response elements (T3REs) have been identified in a variety of promoters including those directing expression of rat GH (rGH), alpha-myosin heavy chain (rMHC), and malic enzyme (rME). A detailed biochemical and genetic analysis of the rGH element has shown that it consists of three hexamers related to the consensus [(A/G)GGT(C/A)A]. We have extended this analysis to the rMHC and rME elements. Binding of highly purified thyroid hormone receptor (T3R) to T3REs was determined using the gel shift assay, and thyroid hormone (T3) induction was measured in transient tranfections. We show that the wild type version of each of the three elements binds T3R dimers cooperatively. Mutational analysis of the rMHC and rME elements identified domains important for binding T3R dimers and allowed a direct determination of the relationship between T3R binding and function. In each element two hexamers are required for dimer binding, and mutations that interfere with dimer formation significantly reduce T3 induction. Similar to the rGH element, the rMHC T3RE contains three hexameric domains arranged as a direct repeat followed by an inverted copy, although the third domain is weaker than in rGH. All three are required for full function and T3R binding. The rME T3RE is a two-hexamer direct repeat T3RE, which also binds T3R monomer and dimer. Across a series of mutant elements, there was a strong correlation between dimer binding in vitro and function in vivo for rMHC (r = 0.99, P less than 0.01) and rME (r = 0.67, P less than 0.05) T3REs. Our results demonstrate a similar pattern of T3R dimer binding to a diverse array of hexameric sequences and arrangements in three wild type T3REs. Addition of nuclear protein enhanced T3R binding but did not alter the specificity of binding to wild type or mutant elements. Binding of purified T3R to T3REs was highly correlated with function, both with and without the addition of nuclear protein. T3R dimer formation is the common

MOLECULAR DYNAMICS SIMULATION OF KINETIC RESOLUTION OF RACEMIC ALCOHOL USING BURKHOLDERIA CEPACIA LIPASE IN ORGANIC SOLVENTS

Directory of Open Access Journals (Sweden)

A. C. Mathpati

2018-03-01

Full Text Available Lipases, a subclass of hydrolases, have gained a lot of importance as they can catalyze esterification, transesterification and hydrolysis reaction in non-aqueous media. Lipases are also widely used for kinetic resolution of racemic alcohols into enantiopure compounds. The lipase activity is affected by organic solvents due to changes in the conformational rigidity of enzymes, the active site, or altering the solvation of the transition state. The activity of lipases strongly depends on the logP value of solvents. Molecular dynamics (MD can help to understand the effect of solvents on lipase conformation as well as protein-ligand complex. In this work, MD simulations of Burkholderia cepacia lipase (BCL and complex between R and S conformation of acetylated form of 1-phenylethanol with BCL using gromacs have been carried in various organic solvents. The RMSD values were within the range of 0.15 to 0.20 nm and radius of gyration was found to be with 1.65 to 1.9 nm. Major changes in the B factor compared to reference structure were observed between residues 60 to 80, 120 to 150 and 240 to 260. Higher unfolding was observed in toluene and diethyl ether compared to hexane and acetonitrile. R acetylated complex was found to favorably bind BCL compared to S form. The predicted enantioselectivity were in good agreement with the experimental data.

Fabrication and functionalization of magnesium nanoparticle for lipase immobilization in n-propyl gallate synthesis

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Abhishek Sharma

2017-10-01

Full Text Available An extracellular lipase partially purified from Bacillus thermoamylovorans BHK67 was effectively immobilized onto modified magnetic MgFe2O4 nanoparticles (NPs. NPs were prepared by the sol-gel auto-combustion method and characterized by Fourier transform infrared (FTIR spectroscopy, X-ray diffraction (XRD, Ultra-Violet–Visible Spectroscopy (UV–vis and atomic force microscopy (AFM. Protein loading reached a saturated amount of about 0.20 mg lipase per milligram of MgFe2O4 NPs with 78.9% binding efficiency. The NPs-bound lipase also showed stability following exposure to n-propanol and iso-propanol or FeCl2 and MgCl2 metal ions at (1 mM at 55 °C. NPs-bound lipase also retained 50% of its original hydrolytic activity even after 8th cycle, as well as after 12 h of incubation at 55 °C. NPs-bound lipase in an esterification reaction of n-propanol and gallic acid (25 mM performed for 12 h at 55 °C produced n-propyl gallate with a conversion rate of 82%. Synthesized n-propyl gallate possessed strong antioxidant activity, which was confirmed by DPPH assay, and in addition has anticancerous activity which was tested on a human L132 cell line.

OPTIMASI ISOLASI LIPASE INDIGENOUS BIJI KAKAO (Theobroma cacao L. The Optimizing of Isolation of Cocoa Bean Indogenous Lipase (Theobroma cacao L.

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I D. G. Mayun Permana

2012-05-01

Full Text Available The aim of the research is to optimize the isolation method of cocoa bean lipase. The research is held by determining the position of lipase on cocoa bean, varying extraction medium and isolation process. The result shows that the lipase of cocoa bean is   cytosolic enzyme. The defatting process do not increase the lipase activity. Polyphenols inhibit the lipase activity, so that removal of the polyphenol will increase the activity. Blocking the polyphenol with polyvinilpolypirrolidone (PVPP will also increase the activity.The optimum consentration of PVPP is 8 %. The lipase activity will reach the highest when homogenized for 10 menit at 10,000 rpm. The best medium extraction for lipase isolation is 0.15 M phosphate buffer pH 7.5 containing sucrose 0.6 M and CaCl  1.0 mM.   ABSTRAK Penelitian ini bertujuan untuk mengoptimasi isolasi lipase indigenous biji kakao. Optimasi diawali dengan menentukan keberadaan lipase kemudian optimasi medium ekstraksi dan proses ekstraksi. Hasil penelitian menunjukkan bahwa lipase berada dalam sitosol. Penghilangan lemak tidak meningkatkan aktivitas lipase. Senyawa polifenol menghambat aktivitas lipase dan penghilangan polifenol dapat meningkatkan aktivitas lipase. Polyvinilpolypirrolidone (PVPP dapat menghambat polifenol sehingga dapat meningkatkan aktivitas lipase. Konsentrasi PVPP optimum adalah 8 % dari berat biji kakao. Proses homogenisasi optimum diperoleh dalam waktu 10 menit pada kecepatan 10.000 rpm. Medium ekstraksi untuk isolasi lipase biji kakao terbaik adalah bufer fosfat 0,15 M  dan pH 7,5 yang mengandung sukrosa 0,6 M dan 1,0 mM CaCl .

Sensitive double-antibody method for simultaneous determination of insulin and growth hormone

International Nuclear Information System (INIS)

Koparanova, O.; Sotirov, G.; Tyrkolev, N.

1982-01-01

A method is described for simultaneous determination of insulin and growth hormone in one sample, using double-antibody technique. The method is characterized by appreciable sensitivity (2.5 μE/ml for insulin and a.2 ng/ml for growth hormone), exactness (variation quotient 6-16 per cent) and reproducibility (96.9-117 per cent). There was no statistically significant difference in the insulin and growth hormone values of the same sera, determined by the here suggested and the standard methods. The necessary test material for examination of either hormone is minimal (0.2 ml). One may thus extend the possibilities for radioimmunologic determination of insulin and growth hormone, when only minor amounts of serum or other biological fluid are available. The method is also less time consuming. Results are reported of statistical processing of an experimental model and different sera determined by the standard method and the one described by the authors. (author)

Recombinant-derived chicken growth hormone used for radioimmunoassay

International Nuclear Information System (INIS)

Proudman, J.A.

1984-01-01

The use of recombinant-derived chicken growth hormone (rcGH) in an avian growth hormone (GH) radioimmunoassay (RIA) procedure is described. Antiserum to turkey GH bound 125 I-labeled rcGH, and unlabeled rcGH or turkey GH displaced binding in a dose-related manner. The dose-response curves of sera and pituitary extract from chickens and turkeys were parallel to the rcGH standard curve. Sera from hypophysectomized (hypox) chickens and turkeys produced no dose-response and did not inhibit binding of labeled rcGH. Recovery of rcGH added to hypox sera was quantitative. Modification of the homologous turkey GH RIA protocol of Proudman and Wentworth (1) to use rcGH made possible either an increase in assay sensitivity or a 3-day reduction in incubation time

Familial lipoprotein lipase deficiency

Science.gov (United States)

... lack an enzyme called lipoprotein lipase. Without this enzyme, the body cannot break down fat from digested food. Fat particles called chylomicrons build up in the blood. Risk factors include a family history of lipoprotein lipase deficiency. The condition is usually ...

Conformation Analysis of T1 Lipase on Alcohols Solvent using Molecular Dynamics Simulation

Science.gov (United States)

Putri, A. M.; Sumaryada, T.; Wahyudi, S. T.

2017-07-01

Biodiesel usually is produced commercially via a transesterification reaction of vegetable oil with alcohol and alkali catalyst. The alkali catalyst has some drawbacks, such as the soap formation during the reaction. T1 Lipase enzyme had been known as a thermostable biocatalyst which is able to produce biodiesel through a cleaner process. In this paper the performance of T1 lipase enzyme as catalyst for transesterification reaction in pure ethanol, methanol, and water solvents were studied using a Molecular Dynamics (MD) Simulation at temperature of 300 K for 10 nanoseconds. The results have shown that in general the conformation of T1 lipase enzyme in methanol is more dynamics as shown by the value of root mean square deviation (RMSD), root mean squared fluctuation (RMSF), and radius of gyration. The highest solvent accessible surface area (SASA) total was also found in methanol due to the contribution of non-polar amino acid in the interior of the protein. Analysis of MD simulation has also revealed that the enzyme structure tend to be more rigid in ethanol environment. The analysis of electrostatic interactions have shown that Glu359-Arg270 salt-bridge pair might hold the key of thermostability of T1 lipase enzyme as shown by its strong and stable binding in all three solvents.

Diminished hepatic growth hormone receptor binding in sex-linked dwarf broiler and leghorn chickens.

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Leung, F C; Styles, W J; Rosenblum, C I; Lilburn, M S; Marsh, J A

1987-02-01

Hepatic growth hormone (GH) receptor binding was compared in normal and sex-linked dwarfs (SLD) from both Hubbard and Cornell strain chickens. At 6, 8, and 20 weeks of age, hepatic GH receptor binding in the Hubbard SLD chickens was significantly lower than that of normal fast-growing birds. At 20 weeks of age, only 2 of 22 SLD chickens in the Hubbard broiler strain showed positive binding at a high enough level to allow for Scatchard analysis. The affinity constants and binding capacities of these two SLD chickens were numerically (but not significantly) lower than those of the normal fast-growing birds. We further examined hepatic GH receptor binding in two closely related White Leghorn strains of chickens that have been maintained as closed breeding populations for many years. We observed no detectable hepatic GH binding in the Cornell SLD chickens (N = 20), as compared to the normal-growing control strain (K strain). In both SLD strains, pretreatment with 4 M MgCl2 did not enhance GH binding, suggesting that there was no endogenous GH binding to the receptor. Based on these data, we suggest that the lack, or greatly reduced number, of GH receptors may be a major contributing factor to the dwarfism observed in these strains.

Signaling-sensitive amino acids surround the allosteric ligand binding site of the thyrotropin receptor.

Science.gov (United States)

Kleinau, Gunnar; Haas, Ann-Karin; Neumann, Susanne; Worth, Catherine L; Hoyer, Inna; Furkert, Jens; Rutz, Claudia; Gershengorn, Marvin C; Schülein, Ralf; Krause, Gerd

2010-07-01

The thyrotropin receptor [thyroid-stimulating hormone receptor (TSHR)], a G-protein-coupled receptor (GPCR), is endogenously activated by thyrotropin, which binds to the extracellular region of the receptor. We previously identified a low-molecular-weight (LMW) agonist of the TSHR and predicted its allosteric binding pocket within the receptor's transmembrane domain. Because binding of the LMW agonist probably disrupts interactions or leads to formation of new interactions among amino acid residues surrounding the pocket, we tested whether mutation of residues at these positions would lead to constitutive signaling activity. Guided by molecular modeling, we performed site-directed mutagenesis of 24 amino acids in this spatial region, followed by functional characterization of the mutant receptors in terms of expression and signaling, measured as cAMP accumulation. We found that mutations V421I, Y466A, T501A, L587V, M637C, M637W, S641A, Y643F, L645V, and Y667A located in several helices exhibit constitutive activity. Of note is mutation M637W at position 6.48 in transmembrane helix 6, which has a significant effect on the interaction of the receptor with the LMW agonist. In summary, we found that a high proportion of residues in several helices surrounding the allosteric binding site of LMW ligands in the TSHR when mutated lead to constitutively active receptors. Our findings of signaling-sensitive residues in this region of the transmembrane bundle may be of general importance as this domain appears to be evolutionarily retained among GPCRs.

Procedures for Sensitive Immunoassay

Energy Technology Data Exchange (ETDEWEB)

Givol, D. [Department of Chemical Immunology, Weizmann Institute of Science, Rehovot (Israel)

1970-02-15

Sensitive immunoassay methods should be applied to small molecules of biological importance, which are non-immunogenic by themselves, such as small peptide hormones (e.g. bradykinin), plant hormones (e.g. indoleacetic acid), nucleotides and other small molecules. Methods of binding these small molecules, as haptens, to immunogenic carriers by various cross-linking agents are described (dicyclohexylcarbodiimide, tolylene-diisocyanate and glutaraldehyde), and the considerations involved in relation to the methods of binding and the specificity of the antibodies formed are discussed. Some uses of antibody bound to bromoacetyl cellulose as an immuno adsorbent convenient for assay of immunoglobulins are described. Finally, the sensitive immunoassay method of chemically modified phage is described. This includes methods of binding small molecules (such as the dinitrophenyl group, penicillin, indoleacetic acid) or proteins (such as insulin, immunoglobulins) to phages. Methods of direct chemical conjugation, or an indirect binding via anti-phage Fab, are described. The phage inactivation method by direct plating and its modifications (such as decision technique and complex inactivation) are compared with the more simple end-point titration method. The inhibition of phage inactivation has some advantages as it does not require radioactive material, or expensive radioactive counters, and avoids the need for separation between bound and unbound antigen. Hence, if developed, it could be used as an alternative to radioimmunoassay. (author)

Potencial de biocatálise enantiosseletiva de lipases microbianas Potential of enantioselective biocatalysis by microbial lipases

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Patrícia de O. Carvalho

2005-08-01

Full Text Available Microbial lipases have a great potential for commercial applications due to their stability, selectivity and broad substrate specificity because many non-natural acids, alcohols or amines can be used as the substrate. Three microbial lipases isolated from Brazilian soil samples (Aspergillus niger; Geotrichum candidum; Penicillium solitum were compared in terms of their stability and as biocatalysts in the enantioselective esterification using racemic substrates in organic medium. The lipase from Aspergillus niger showed the highest activity (18.2 U/mL and was highly thermostable, retaining 90% and 60% activity at 50 ºC and 60 ºC after 1 hour, respectively. In organic medium, this lipase provided the best results in terms of enantiomeric excess of the (S-active acid (ee = 6.1% and conversion value (c = 20% in the esterification of (R,S-ibuprofen with 1-propanol in isooctane. The esterification reaction of the racemic mixture of (R,S-2-octanol with decanoic acid proceeded with high enantioselectivity when lipase from Aspergillus niger (E = 13.2 and commercial lipase from Candida antarctica (E = 20 were employed.

Application of alkaline thermo-stable lipase(s) enzyme produced from irradiated microbial isolate in the field of detergent technology

International Nuclear Information System (INIS)

Ahmed, O.E.A.M.S

2010-01-01

Due to continuous demand for manufacture of high quality, low coast industrial detergents containing lipolytic enzymes and due to continuous accumulation of enviro-agro-industrial wastes which are good and suitable conditions for growth and reproduction of pathogenic microorganisms, our study aims at isolating thermoalkalophilic lipase producer microorganisms from enviro-agro-industrial wastes and selection of the most potent isolate for studying physiological conditions controlling enzyme formation also purification characterization and some applications on purified and crude enzyme as bio-detergent. Some environmental and industrial wastes were collected from different places. The industrial wastes include, cotton seed, soyabean, sun flower, lin seed and olive oil wastes. Environmental wastes include poultry and fish wastes, all these wastes were dried at 70 degree C, grounded and used for isolation of microorganisms and lipase(s) production.Nine thermoalkalophilic bacterial isolates were isolated from enviro-agro-industrial wastes at ph 11.5 and 70 degree C. They were purified and screening for their ability of thermoalkalo-stable lipase(s) formation, this is followed by examining the effect of different nutritional media and exposure of bacterial isolates to different doses of gamma irradiation and the influence of these radiation on lipase(s) productivity by these isolates. From the results it was found that.1- The most potent lipase(s) forming bacterial isolates were isolates number B 2 and B 3 which cultivated on medium A amended with fish-wastes as being the best nutritional medium for enzyme formation. 2-Bacterial isolate B 2 finally was selected as being the most potent lipase(s) forming bacterial isolate cultivated on fish-wastes and yeast extract (in tap water) and identified according to key's of Bergey Manual of Systematic Bacteriology (1984) as being Bacillus brevis B 2 .The optimum culture conditions for maximum biosynthesis of extracellular lipase(s

Activity and stability of immobilized lipases in lipase-catalyzed modification of peanut oil

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Soumanou Mohamed M.

2004-11-01

Full Text Available Fatty acid release during lipolysis of peanut oil using microbial free and immobilized lipases in aqueous media was developed. Immobilized lipase from Rhizomucor miehei (RML gave the best result from its ability to clive different fatty acids from peanut oil in such media. In organic solvent, interesterification of peanut oil with tricaprylin using immobilized lipases from RML, Chromobacterium viscosum (CVL and Candida rugosa (CRL was performed. The best substrate molar ratio of tricaprylin to peanut oil found was in the range 0.7 to 0.8. Using substrate molar ratio 0.7, high amount of structured triglyceride ST (about 35% MLM, 44% LML triglyceride fractions was obtained with lipase from RML in n-hexane. The results found in solvent free system were in some cases quite similar to that obtained in organic solvent. In nine successive batch interesterification in solvent free medium using immobilized RML and CRL, no significant loss of amount of both produced triacylglycerol fractions until batch 7 was observed with RML.

Lipase Test: MedlinePlus Lab Test Information

Science.gov (United States)

... page: https://medlineplus.gov/labtests/lipasetest.html Lipase Test To use the sharing features on this page, please enable JavaScript. What is a lipase test? Lipase is a type of protein made by ...

Orientating lipase molecules through surface chemical control for enhanced activity: A QCM-D and ToF-SIMS investigation.

Science.gov (United States)

Joyce, Paul; Kempson, Ivan; Prestidge, Clive A

2016-06-01

Bio-active materials consisting of lipase encapsulated within porous silica particles were engineered to control the adsorption kinetics and molecular orientation of lipase, which play critical roles in the digestion kinetics of triglycerides. The adsorption kinetics of Candida antartica lipase A (CalA) was monitored using quartz crystal microbalance with dissipation (QCM-D) and controlled by altering the hydrophobicity of a silica binding support. The extent of adsorption was 2-fold greater when CalA was adsorbed onto hydrophobic silica compared to hydrophilic silica. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) fragmentation patterns, in conjunction with multivariate statistics, demonstrated enhanced exposure of the lipase's catalytic domain, specifically the histidine group responsible for activity, when CalA was adsorbed on hydrophilic silica. Consequently, lipid digestion kinetics were enhanced when CalA was loaded in hydrophilic porous silica particles, i.e., a 2-fold increase in the pseudo-first-order rate constant for digestion when compared to free lipase. In contrast, digestion kinetics were inhibited when CalA was hosted in hydrophobic porous silica, i.e., a 5-fold decrease in pseudo-first-order rate constant for digestion when compared to free lipase. These findings provide valuable insights into the mechanism of lipase action which can be exploited to develop smarter food and drug delivery systems consisting of porous lipid-based materials. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of insulin-like growth factor-1 and insulin like growth factor binding protein-3 in diagnosis of growth hormone deficiency in short-stature children

International Nuclear Information System (INIS)

Ali, A.; Hashim, R.; Khan, F.A.; Sattar, A.; Ijaz, A.; Manzoor, S.M.; Younas, M.

2009-01-01

Growth Hormone Deficiency (GHD) is conventionally diagnosed and confirmed by diminished peak Growth Hormone (GH) levels to provocative testing. Serum Insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) are under the influence of GH and reflect the spontaneous endogenous GH secretion. Owing to the absence of a circadian rhythm, it is possible to take individual measurements of IGF-1 and IGFBP-3 at any time of the day for evaluation of GH status instead of subjecting the individual to cumbersome provocative tests. Objectives of this study were to compare IGF-1 and IGFBP-3 assays with Exercise and L-Dopa stimulation tests in the diagnosis of growth hormone deficiency in short stature children using ITT as gold standard. Methods: This validation study was conducted at Department of Chemical Pathology and Endocrinology, AFIP, Rawalpindi, from November 2005 to October 2006. Fifty-two short stature children were included in the study. Basal samples for GH levels and simultaneous IGF-1 and IGFBP-3 measurements were obtained and afterwards all children were subjected to sequential exercise and LDopa stimulation tests. Insulin Tolerance Test (ITT) was performed one week later with all the necessary precautionary measures. On the basis of ITT results, children were divided into two groups, i.e., 31 growth hormone deficient and 21 Normal Variant Short Stature (NVSS). Results: The diagnostic value of exercise stimulation test remained highest with sensitivity 90.3%, specificity 76.0%, Positive Predictive Value (PPV) 84.84%, Negative Predictive Value (NPV) 84.2% and accuracy 84.6%. The conventional L-Dopa stimulation had sensitivity 96.7%, specificity 38.0%, PPV 69.7%, NPV 88.8 % and accuracy 73.0%. The serum IGF-1 and IGFBP-3 levels were positively correlated with post ITT peak GH levels (r= 0.527, r=0.464 respectively, both p<0.001). The diagnostic value of IGF-1 had sensitivity 83.87%, specificity 76.2%, PPV 83.87%, NPV 76.2% and

21 CFR 184.1415 - Animal lipase.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Animal lipase. 184.1415 Section 184.1415 Food and... Substances Affirmed as GRAS § 184.1415 Animal lipase. (a) Animal lipase (CAS Reg. No. 9001-62-1) is an enzyme preparation obtained from edible forestomach tissue of calves, kids, or lambs, or from animal pancreatic...

Carriers of a VEGFA enhancer polymorphism selectively binding CHOP/DDIT3 are predisposed to increased circulating levels of thyroid-stimulating hormone

DEFF Research Database (Denmark)

Ahluwalia, Tarun Veer Singh; Troelsen, Jesper Thorvald; Balslev-Harder, Marie

2017-01-01

BACKGROUND: Levels of serum thyroid-stimulating hormone (TSH) indicate thyroid function, because thyroid hormone negatively controls TSH release. Genetic variants in the vascular endothelial growth factor A (VEGFA) gene are associated with TSH levels. The aim of this study was to characterise...... levels (p=0.0014). The SNP rs881858 is located in a binding site for CHOP (C/EBP homology protein) and c/EBPβ (ccaat enhancer binding protein β). Reporter-gene analysis showed increased basal enhancer activity of the rs881858 A-allele versus the G-allele (34.5±9.9% (average±SEM), p=0.0012), while co...

pH regulation of the kinetic stability of the lipase from Thermomyces lanuginosus.

Science.gov (United States)

Wang, H; Andersen, K K; Sehgal, P; Hagedorn, J; Westh, P; Borch, K; Otzen, D E

2013-01-08

Thermomyces lanuginosus lipase (TlL) is a kinetically stable protein, resistant toward both denaturation and refolding in the presence of the ionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant decyl maltoside (DecM). We investigate the pH dependence of this kinetic stability. At pH 8, TlL remains folded and enzymatically active at multimillimolar surfactant concentrations but fails to refold from the acid urea-denatured state at submillimolar concentrations of SDS and DecM, indicating a broad concentration range of kinetic trapping or hysteresis. At pH 8, very few SDS molecules bind to TlL. The hysteresis SDS concentration range shrinks when moving to pH 4-6; in this pH range, SDS binds as micellelike clusters. Although hysteresis can be eliminated by reducing disulfide bonds, destabilizing the native state, and lowering the unfolding activation barrier, SDS sensitivity is not directly linked to intrinsic kinetic stability [its resistance to the general chemical denaturant guanidinium chloride (GdmCl)], because TlL unfolds more slowly in GdmCl at pH 6.0 than at pH 8.0. However, the estimated net charge drops from approximately -12 to approximately -5 between pH 8 and 6. SDS denatures TlL at pH 6.0 by nucleating via a critical number of bound SDS molecules on the surface of native TlL to form clusters. These results imply that SDS sensitivity is connected to the availability of appropriately charged regions on the protein. We suggest that conformational rigidity is a necessary but not sufficient feature of SDS resistance, because this has to be combined with sufficient negative electrostatic potential to avoid extensive SDS binding.

Pattern of human chorionic gonadotropin binding in the polycystic ovary

International Nuclear Information System (INIS)

Brawer, J.; Richard, M.; Farookhi, R.

1989-01-01

The histologic evolution of polycystic ovaries in the estradiol valerate-treated rat coincides with the development of a unique plasma pattern of luteinizing hormone. To assess the role of luteinizing hormone in polycystic ovaries, it is necessary to evaluate the luteinizing hormone sensitivity of the specific tissues in the polycystic ovary. Therefore, we examined the pattern of luteinizing hormone binding sites in polycystic ovaries. Rats at 4 or 8 weeks after estradiol valerate treatment each received an intrajugular injection of iodine 125-labeled human chorionic gonadotropin. Some rats also received a 1000-fold excess of unlabeled human chorionic gonadotropin in the same injection. Ovaries were prepared for autoradiography. Dense accumulations of grains occurred over the theca of normal and atretic secondary follicles in all ovaries and over clusters of secondary interstitial cells. The iodine label was variable over the typically hypertrophied theca of precystic follicles. The theca of definitive cysts showed little or no label. These results indicate that cyst formation coincides with the loss of luteinizing hormone/human chorionic gonadotropin binding to the affected follicles

Pattern of human chorionic gonadotropin binding in the polycystic ovary

Energy Technology Data Exchange (ETDEWEB)

Brawer, J.; Richard, M.; Farookhi, R. (McGill Univ., Montreal, Quebec (Canada))

1989-08-01

The histologic evolution of polycystic ovaries in the estradiol valerate-treated rat coincides with the development of a unique plasma pattern of luteinizing hormone. To assess the role of luteinizing hormone in polycystic ovaries, it is necessary to evaluate the luteinizing hormone sensitivity of the specific tissues in the polycystic ovary. Therefore, we examined the pattern of luteinizing hormone binding sites in polycystic ovaries. Rats at 4 or 8 weeks after estradiol valerate treatment each received an intrajugular injection of iodine 125-labeled human chorionic gonadotropin. Some rats also received a 1000-fold excess of unlabeled human chorionic gonadotropin in the same injection. Ovaries were prepared for autoradiography. Dense accumulations of grains occurred over the theca of normal and atretic secondary follicles in all ovaries and over clusters of secondary interstitial cells. The iodine label was variable over the typically hypertrophied theca of precystic follicles. The theca of definitive cysts showed little or no label. These results indicate that cyst formation coincides with the loss of luteinizing hormone/human chorionic gonadotropin binding to the affected follicles.

Uremic Toxins and Lipases in Haemodialysis: A Process of Repeated Metabolic Starvation

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Bernd Stegmayr

2014-04-01

Full Text Available Severe kidney disease results in retention of uremic toxins that inhibit key enzymes for lipid breakdown such as lipoprotein lipase (LPL and hepatic lipase (HL. For patients in haemodialysis (HD and peritoneal dialysis (PD the LPL activity is only about half of that of age and gender matched controls. Angiopoietin, like protein 3 and 4, accumulate in the uremic patients. These factors, therefore, can be considered as uremic toxins. In animal experiments it has been shown that these factors inhibit the LPL activity. To avoid clotting of the dialysis circuit during HD, anticoagulation such as heparin or low molecular weight heparin are added to the patient. Such administration will cause a prompt release of the LPL and HL from its binding sites at the endothelial surface. The liver rapidly degrades the release plasma compound of LPL and HL. This results in a lack of enzyme to degrade triglycerides during the later part of the HD and for another 3–4 h. PD patients have a similar baseline level of lipases but are not exposed to the negative effect of anticoagulation.

A simple method for measuring sex-hormone binding protein (SHBP) - typical values in men and women and in pregnant women

International Nuclear Information System (INIS)

Tafurt, C.A.; Estrada, R. de

1978-01-01

Assuming that the binding forces between steroid hormones and their binding proteins are similar to those between antigens and their antibodies, the authors describe how to determine SHBP activity by a dilution method analogous to that used for titration of antisera in radioimmunoassay. The method consists of the following stages: (1) plasma dilution; (2) incubation of the dilution with 20,000dis/min of 1,2- 3 H-testosterone; (3) separation of the fraction of tracer bound to the SHBP by precipitation with ammonium sulphate; (4) centrifugation and measurement of the supernatant; and (5) plotting of the results on a graph where the axis of ordinates represents the quotient given by bound steroid over free steroid (U/L) and the abscissa represents the plasma dilutions. The values are expressed as the 50% bound titre. An advantage of the method is the higher sensitivity of the dilution curves in the steepest part where the 50% bound is encountered; it is thus not necessary to use the saturation part of the curves where sensitivity is lost owing to the steeper slope. A further advantage of the method is that there is no need for costly processes such as dialysis. The SHBP values obtained for healthy subjects were as follows: 1/5 for men, 1/93 for women, and 1/360 in pregnant women. These physiological values showed no overlapping. (author)

Sex hormone-binding globulin (SHBG expression in ovarian carcinomas and its clinicopathological associations.

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Ruixia Huang

Full Text Available Sex hormone-binding globulin (SHBG is known as a carrier protein. It is classically thought to be mainly synthesized in the liver and then secreted into the circulating system, where it binds to sex steroids with a high affinity and modulates the bio-availability of the hormones. Other organs known to produce SHBG include brain, uterus, testis, prostate, breast and ovary, and the local expressed SHBG may play an important role in tumor development. However, SHBG expression status and its clinicopathological significance in ovarian cancer cells are not reported yet. In our present study, we examined and found the variable SHBG expression in four ovarian cancer cell lines (OV-90, OVCAR-3, SKOV-3 and ES-2 by immunocytochemistry and Western blotting. We then extended our study to 248 ovarian carcinoma samples, which were collected at The Norwegian Radium Hospital, Oslo University Hospital with complete clinical information, and discovered that SHBG was variably expressed in these ovarian carcinomas. Higher level of SHBG expression was significantly associated with more aggressive histological subtype (p = 0.022, higher FIGO stage (p = 0.018 and higher histological grade (grade of differentiation, p = 0.020, although association between SHBG expression and OS/PFS was not observed. Our results demonstrate that ovarian cancer cells produce SHBG and higher SHBG expression in ovarian carcinoma is associated with unfavorable clinicopathological features.

ISOLATION AND IDENTIFICATION OF LIPASE-PRODUCING FUNGI FROM LOCAL OLIVE OIL MANUFACTURE IN EAST OF ALGERIA

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ALIMA RIHANI

2018-03-01

Full Text Available The main objective of this work was primary screening and isolation of lipase-producing microorganisms from oil-mill waste. For the screening of fungal strains with lipolytic activity, we employed a sensitive agar plate method, using a medium supplemented with CaCl2 and Tween 80. Another Tributyrin lipase activity was detected from clearing zones due to the hydrolysis of the triacylglycerols. The evolution of biomass and enzyme production has been assayed. A quantitative analysis of lipase activity was performed by the titration method using olive oil as a substrate supplemented with glucose or Tween 80. We have isolated some lipolytic strains from oil-mill effluent. Three of them were found to be excellent lipase producers that were identified as Penicillium sp, Aspergillus fumigatus and Aspergillus terreus. Lipolytic activity and biomass were enhanced in the medium supplemented by glucose. Tween 80 is also considered as a best inducer at the concentration of 1 %. In this condition, these isolates showed maximum lipase production within 24 h; achieved (3.91 IU‧mL-1 ± 0.12 for Penicillium sp.

Structure of the Mr 140,000 growth hormone-dependent insulin-like growth factor binding protein complex: Determination by reconstitution and affinity-labeling

International Nuclear Information System (INIS)

Baxter, R.C.; Martin, J.L.

1989-01-01

To determine the structure of the high molecular weight, growth hormone-dependent complex between the insulin-like growth factors (IGF-I and IGF-II) and their binding proteins in human serum, we have reconstituted the complex from its purified component proteins and analyzed it by gel electrophoresis and autoradiography after covalent cross-linking. The proteins tested in reconstitution mixtures were an acid-labile Mr 84,000-86,000 glycoprotein doublet (alpha subunit), an acid-stable Mr 47,000-53,000 glycoprotein doublet with IGF-binding activity (BP-53 or beta subunit), and IGF-I or IGF-II (gamma subunit). In incubations containing any one of the three subunits 125I-labeled and the other two unlabeled, identical 125I-labeled alpha-beta-gamma complexes of Mr 140,000 were formed. Minor bands of Mr 120,000 and 90,000 were also seen, thought to represent a partially deglycosylated form of the alpha-beta-gamma complex, and an alpha-gamma complex arising as a cross-linking artifact. When serum samples from subjects of various growth hormone status were affinity-labeled with IGF-II tracer, a growth hormone-dependent Mr 140,000 band was seen, corresponding to the reconstituted alpha-beta-gamma complex. Other growth hormone-dependent labeled bands, of Mr 90,000 (corresponding to alpha-gamma), Mr 55,000-60,000 (corresponding to labeled beta-subunit doublet), and smaller bands of Mr 38,000, 28,000, and 23,000-25,000 (corresponding to labeled beta-subunit degradation products), were also seen in the affinity-labeled serum samples and in the complex reconstituted from pure proteins. All were immunoprecipitable with an anti-BP-53 antiserum. We conclude that the growth hormone-dependent Mr 140,000 IGF-binding protein complex in human serum has three components: the alpha (acid-labile) subunit, the beta (binding) subunit, and the gamma (growth factor) subunit

Calcium regulates ATP-sensitive microtubule binding by Chlamydomonas outer arm dynein.

Science.gov (United States)

Sakato, Miho; King, Stephen M

2003-10-31

The Chlamydomonas outer dynein arm contains three distinct heavy chains (alpha, beta, and gamma) that exhibit different motor properties. The LC4 protein, which binds 1-2 Ca2+ with KCa = 3 x 10-5 m, is associated with the gamma heavy chain and has been proposed to act as a sensor to regulate dynein motor function in response to alterations in intraflagellar Ca2+ levels. Here we genetically dissect the outer arm to yield subparticles containing different motor unit combinations and assess the microtubule-binding properties of these complexes both prior to and following preincubation with tubulin and ATP, which was used to inhibit ATP-insensitive (structural) microtubule binding. We observed that the alpha heavy chain exhibits a dominant Ca2+-independent ATP-sensitive MT binding activity in vitro that is inhibited by attachment of tubulin to the structural microtubule-binding domain. Furthermore, we show that ATP-sensitive microtubule binding by a dynein subparticle containing only the beta and gamma heavy chains does not occur at Ca2+ concentrations below pCa 6 but is maximally activated above pCa 5. This activity was not observed in mutant dyneins containing small deletions in the microtubule-binding region of the beta heavy chain or in dyneins that lack both the alpha heavy chain and the motor domain of the beta heavy chain. These findings strongly suggest that Ca2+ binding directly to a component of the dynein complex regulates ATP-sensitive interactions between the beta heavy chain and microtubules and lead to a model for how individual motor units are controlled within the outer dynein arm.

Role of Hepatic Lipase and Endothelial Lipase in High-Density Lipoprotein-Mediated Reverse Cholesterol Transport

NARCIS (Netherlands)

Annema, Wijtske; Tietge, Uwe J. F.

Reverse cholesterol transport (RCT) constitutes a key part of the atheroprotective properties of high-density lipoproteins (HDL). Hepatic lipase (HL) and endothelial lipase (EL) are negative regulators of plasma HDL cholesterol levels. Although overexpression of EL decreases overall

Sex hormone binding globulin, free estradiol index, and lipid profiles in girls with precocious puberty

Directory of Open Access Journals (Sweden)

Hyun-Wook Chae

2013-06-01

Full Text Available PurposeSex hormone-binding globulin (SHBG modulates the availability of biologically active free sex hormones. The regulatory role of SHBG might be important in the relationship between hormone levels and the modification of lipid profiles in girls with precocious puberty. However, few studies have evaluated the relationship of SHBG, free estradiol index (FEI, and lipid levels in these girls.MethodsOne hundred and nine girls less than 8 years of age with pubertal development were enrolled. FEI was calculated with SHBG and estradiol (E2. We analyzed SHBG between peak luteinizing hormone (LH≥5 (IU/L (group 1 and LH<5 (IU/L (group 2 through a gonadotropin releasing hormone stimulation test.ResultsBody mass index (BMI standard deviation score (SDS was higher in group 2 than in group 1 (P=0.004. Serum SHBG levels did not differ and FEI was not higher in group 1 (P=0.122. Serum cholesterol, HDL, and LDL did not differ; however, triglyceride levels were higher in group 2 (P=0.023. SHBG was negatively correlated with bone age advancement, BMI, BMI SDS, and FEI, and was positively correlated with HDL. However, SHBG was not correlated with E2 or peak LH.ConclusionSerum SHBG itself might not be associated with precocious puberty in girls, but it might be related to BMI and lipid profiles. Further studies are needed to reveal the relationship between sex hormone and obesity in girls with precocious puberty.

Lipase production by recombinant strains of Aspergillus niger expressing a lipase-encoding gene from Thermomyces lanuginosus

DEFF Research Database (Denmark)

Prathumpai, Wai; Flitter, S.J.; Mcintyre, Mhairi

2004-01-01

Two recombinant strains of Aspergillus niger (NW 297-14 and NW297-24) producing a heterologous lipase from Thermomyces lanuginosus were constructed. The heterologous lipase was expressed using the TAKA amylase promoter from Aspergillus oryzae. The production kinetics of the two strains on different...... shows that it is possible to obtain high productivities of heterologous fungal enzymes in A. niger. However, SDS-PAGE analysis showed that most of the produced lipase was bound to the cell wall....

Some theoretical aspects of hormone receptor determination

International Nuclear Information System (INIS)

Sluiter, W.J.

1981-01-01

Suitable antisera for determination of hormone receptors are not available for the majority of hormone receptors. Therefore, the determination of hormone receptors is mostly performed in terms of binding capacity for the appropriate hormone, using radioactive hormone labels. Some theoretical aspects of such a receptor determination are discussed including the length of incubation (total or unoccupied receptor concentration), single point or multiple point (Scatchard) analysis (regarding the influence of other specific binders), the correction procedure for non-specific binding and the influence of the circulating hormone level. (Auth.)

Estradiol potentiation of gonadotropin-releasing hormone responsiveness in the anterior pituitary is mediated by an increase in gonadotropin-releasing hormone receptors

International Nuclear Information System (INIS)

Menon, M.; Peegel, H.; Katta, V.

1985-01-01

In order to investigate the mechanism by which 17 beta-estradiol potentiates the action of gonadotropin-releasing hormone on the anterior pituitary in vitro, cultured pituitary cells from immature female rats were used as the model system. Cultures exposed to estradiol at concentrations ranging from 10(-10) to 10(-6) mol/L exhibited a significant augmentation of luteinizing hormone release in response to a 4-hour gonadotropin-releasing hormone (10 mumol/L) challenge at a dose of 10(-9) mol/L compared to that of control cultures. The estradiol augmentation of luteinizing hormone release was also dependent on the duration of estradiol exposure. When these cultures were incubated with tritium-labeled L-leucine, an increase in incorporation of radiolabeled amino acid into total proteins greater than that in controls was observed. A parallel stimulatory effect of estradiol on iodine 125-labeled D-Ala6 gonadotropin-releasing hormone binding was observed. Cultures incubated with estradiol at different concentrations and various lengths of time showed a significant increase in gonadotropin-releasing hormone binding capacity and this increase was abrogated by cycloheximide. Analysis of the binding data showed that the increase in gonadotropin-releasing hormone binding activity was due to a change in the number of gonadotropin-releasing hormone binding sites rather than a change in the affinity. These results suggest that (1) estradiol treatment increases the number of pituitary receptors for gonadotropin-releasing hormone, (2) the augmentary effect of estradiol on luteinizing hormone release at the pituitary level might be mediated, at least in part, by the increase in the number of binding sites of gonadotropin-releasing hormone, and (3) new protein synthesis may be involved in estradiol-mediated gonadotropin-releasing hormone receptor induction

Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae

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Seniwati Dali

2011-01-01

Full Text Available Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

The effects of GH and hormone replacement therapy on serum concentrations of mannan-binding lectin, surfactant protein D and vitamin D binding protein in Turner syndrome

DEFF Research Database (Denmark)

Gravholt, Claus Højbjerg; Leth-Larsen, Rikke; Lauridsen, Anna Lis

2004-01-01

function. In the present study we examined whether GH or hormone replacement therapy (HRT) in Turner syndrome (TS) influence the serum concentrations of MBL and two other proteins partaking in the innate immune defence, surfactant protein D (SP-D) and vitamin D binding protein (DBP). DESIGN: Study 1...

Binding of triiodothyronine to rat liver nuclear matrix. influence of thyroid hormones on the phosphorylation of nuclear matrix proteins

International Nuclear Information System (INIS)

Adylova, A.T.; Atakhanova, B.A.

1986-01-01

The interaction of thyroid hormones with rat liver nuclear matrix proteins was investigated. It was shown that the nuclear matrix contains sites that bind triiodothyronine with high affinity (K = 1.07.10 9 M -1 ) and limited capacity (the maximum binding capacity is equal to 28 /SUP a/ .5 fmoles of triiodothyronine per 100 ug protein). Electrophoretic identification of the matrix proteins that bind triiodothyronine was performed. The molecular weight of the main triiodothyronine-binding fraction is 50,000-52,000. It was shown that the administration of triiodothyronine to thyroidectomized rats stimulates the phosphorylation of all the protein fractions of the nuclear matrix

Lack of hormone binding in COS-7 cells expressing a mutated growth hormone receptor found in Laron dwarfism.

Science.gov (United States)

Edery, M; Rozakis-Adcock, M; Goujon, L; Finidori, J; Lévi-Meyrueis, C; Paly, J; Djiane, J; Postel-Vinay, M C; Kelly, P A

1993-01-01

A single point mutation in the growth hormone (GH) receptor gene generating a Phe-->Ser substitution in the extracellular binding domain of the receptor has been identified in one family with Laron type dwarfism. The mutation was introduced by site-directed mutagenesis into cDNAs encoding the full-length rabbit GH receptor and the extracellular domain or binding protein (BP) of the human and rabbit GH receptor, and also in cDNAs encoding the full length and the extracellular domain of the related rabbit prolactin (PRL) receptor. All constructs were transiently expressed in COS-7 cells. Both wild type and mutant full-length rabbit GH and PRL receptors, as well as GH and prolactin BPs (wild type and mutant), were detected by Western blot in cell membranes and concentrated culture media, respectively. Immunofluorescence studies showed that wild type and mutant full-length GH receptors had the same cell surface and intracellular distribution and were expressed with comparable intensities. In contrast, all mutant forms (full-length receptors or BPs), completely lost their modify the synthesis ligand. These results clearly demonstrate that this point mutation (patients with Laron syndrome) does not modify the synthesis or the intracellular pathway of receptor proteins, but rather abolishes ability of the receptor or BP to bind GH and is thus responsible for the extreme GH resistance in these patients. Images PMID:8450064

Smart conjugated polymer nanocarrier for healthy weight loss by negative feedback regulation of lipase activity

Science.gov (United States)

Chen, Yu-Lei; Zhu, Sha; Zhang, Lei; Feng, Pei-Jian; Yao, Xi-Kuang; Qian, Cheng-Gen; Zhang, Can; Jiang, Xi-Qun; Shen, Qun-Dong

2016-02-01

Healthy weight loss represents a real challenge when obesity is increasing in prevalence. Herein, we report a conjugated polymer nanocarrier for smart deactivation of lipase and thus balancing calorie intake. After oral administration, the nanocarrier is sensitive to lipase in the digestive tract and releases orlistat, which deactivates the enzyme and inhibits fat digestion. It also creates negative feedback to control the release of itself. The nanocarrier smartly regulates activity of the lipase cyclically varied between high and low levels. In spite of high fat diet intervention, obese mice receiving a single dose of the nanocarrier lose weight over eight days, whereas a control group continues the tendency to gain weight. Daily intragastric administration of the nanocarrier leads to lower weight of livers or fat pads, smaller adipocyte size, and lower total cholesterol level than that of the control group. Near-infrared fluorescence of the nanocarrier reveals its biodistribution.Healthy weight loss represents a real challenge when obesity is increasing in prevalence. Herein, we report a conjugated polymer nanocarrier for smart deactivation of lipase and thus balancing calorie intake. After oral administration, the nanocarrier is sensitive to lipase in the digestive tract and releases orlistat, which deactivates the enzyme and inhibits fat digestion. It also creates negative feedback to control the release of itself. The nanocarrier smartly regulates activity of the lipase cyclically varied between high and low levels. In spite of high fat diet intervention, obese mice receiving a single dose of the nanocarrier lose weight over eight days, whereas a control group continues the tendency to gain weight. Daily intragastric administration of the nanocarrier leads to lower weight of livers or fat pads, smaller adipocyte size, and lower total cholesterol level than that of the control group. Near-infrared fluorescence of the nanocarrier reveals its biodistribution

Structure-guided modification of Rhizomucor miehei lipase for production of structured lipids.

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Jun-Hui Zhang

Full Text Available To improve the performance of yeast surface-displayed Rhizomucor miehei lipase (RML in the production of human milk fat substitute (HMFS, we mutated amino acids in the lipase substrate-binding pocket based on protein hydrophobicity, to improve esterification activity. Five mutants: Asn87Ile, Asn87Ile/Asp91Val, His108Leu/Lys109Ile, Asp256Ile/His257Leu, and His108Leu/Lys109Ile/Asp256Ile/His257Leu were obtained and their hydrolytic and esterification activities were assayed. Using Discovery Studio 3.1 to build models and calculate the binding energy between lipase and substrates, compared to wild-type, the mutant Asp256Ile/His257Leu was found to have significantly lower energy when oleic acid (3.97 KJ/mol decrease and tripalmitin (7.55 KJ/mol decrease were substrates. This result was in accordance with the esterification activity of Asp256Ile/His257Leu (2.37-fold of wild-type. The four mutants were also evaluated for the production of HMFS in organic solvent and in a solvent-free system. Asp256Ile/His257Leu had an oleic acid incorporation of 28.27% for catalyzing tripalmitin and oleic acid, and 53.18% for the reaction of palm oil with oleic acid. The efficiency of Asp256Ile/His257Leu was 1.82-fold and 1.65-fold that of the wild-type enzyme for the two reactions. The oleic acid incorporation of Asp256Ile/His257Leu was similar to commercial Lipozyme RM IM for palm oil acidolysis with oleic acid. Yeast surface-displayed RML mutant Asp256Ile/His257Leu is a potential, economically feasible catalyst for the production of structured lipids.

Structure-guided modification of Rhizomucor miehei lipase for production of structured lipids.

Science.gov (United States)

Zhang, Jun-Hui; Jiang, Yu-Yan; Lin, Ying; Sun, Yu-Fei; Zheng, Sui-Ping; Han, Shuang-Yan

2013-01-01

To improve the performance of yeast surface-displayed Rhizomucor miehei lipase (RML) in the production of human milk fat substitute (HMFS), we mutated amino acids in the lipase substrate-binding pocket based on protein hydrophobicity, to improve esterification activity. Five mutants: Asn87Ile, Asn87Ile/Asp91Val, His108Leu/Lys109Ile, Asp256Ile/His257Leu, and His108Leu/Lys109Ile/Asp256Ile/His257Leu were obtained and their hydrolytic and esterification activities were assayed. Using Discovery Studio 3.1 to build models and calculate the binding energy between lipase and substrates, compared to wild-type, the mutant Asp256Ile/His257Leu was found to have significantly lower energy when oleic acid (3.97 KJ/mol decrease) and tripalmitin (7.55 KJ/mol decrease) were substrates. This result was in accordance with the esterification activity of Asp256Ile/His257Leu (2.37-fold of wild-type). The four mutants were also evaluated for the production of HMFS in organic solvent and in a solvent-free system. Asp256Ile/His257Leu had an oleic acid incorporation of 28.27% for catalyzing tripalmitin and oleic acid, and 53.18% for the reaction of palm oil with oleic acid. The efficiency of Asp256Ile/His257Leu was 1.82-fold and 1.65-fold that of the wild-type enzyme for the two reactions. The oleic acid incorporation of Asp256Ile/His257Leu was similar to commercial Lipozyme RM IM for palm oil acidolysis with oleic acid. Yeast surface-displayed RML mutant Asp256Ile/His257Leu is a potential, economically feasible catalyst for the production of structured lipids.

Metabolic and hormonal alterations in cats with hepatic lipidosis.

Science.gov (United States)

Brown, B; Mauldin, G E; Armstrong, J; Moroff, S D; Mauldin, G N

2000-01-01

Hepatic lipidosis in cats is a commonly diagnosed hepatobiliary disease of unknown cause. The purpose of this prospective study was to characterize the blood hormone and lipid status of cats with hepatic lipidosis, and to compare this status to that of cats with other types of liver disease and to control cats. Twenty-three cats with hepatic disease were assigned to 1 of 2 groups on the basis of cytopathologic or histopathologic examination of the liver: group 1, hepatic lipidosis (n = 18); or group 2, cholangiohepatitis (n = 5). Ten healthy young adult cats were used as controls. Food was withheld from control animals for 24 hours before blood collection. Concentrations of plasma glucagon and serum insulin, cortisol, thyroxine, triglycerides, cholesterol, phospholipids, and nonesterified fatty acids (NEFAs) were determined in all cats, in addition to routine hematologic and serum biochemical testing. Cats with hepatic lipidosis had higher serum NEFA concentrations than cats with cholangiohepatitis or control cats (P lipidosis or control cats (P hepatic lipidosis. Serum insulin concentrations were significantly higher in control cats than in diseased cats (P hepatic disease. The high concentration of NEFAs in cats with hepatic lipidosis suggests that at least 1 factor in the pathogenesis of this syndrome may involve the regulation of hormone-sensitive lipase.

Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase

International Nuclear Information System (INIS)

Yuecel, Yasin; Demir, Cevdet; Dizge, Nadir; Keskinler, Buelent

2011-01-01

Lipase enzyme from Aspergillus oryzae (EC 3.1.1.3) was immobilized onto a micro porous polymeric matrix which contains aldehyde functional groups and methyl esters of long chain fatty acids (biodiesel) were synthesized by transesterification of crude canola oil using immobilized lipase. Micro porous polymeric matrix was synthesized from styrene-divinylbenzene (STY-DVB) copolymers by using high internal phase emulsion technique and two different lipases, Lipozyme TL-100L ® and Novozym 388 ® , were used for immobilization by both physical adsorption and covalent attachment. Biodiesel production was carried out with semi-continuous operation. Methanol was added into the reactor by three successive additions of 1:4 M equivalent of methanol to avoid enzyme inhibition. The transesterification reaction conditions were as follows: oil/alcohol molar ratio 1:4; temperature 40 o C and total reaction time 6 h. Lipozyme TL-100L ® lipase provided the highest yield of fatty acid methyl esters as 92%. Operational stability was determined with immobilized lipase and it indicated that a small enzyme deactivation occurred after used repeatedly for 10 consecutive batches with each of 24 h. Since the process is yet effective and enzyme does not leak out from the polymer, the method can be proposed for industrial applications. -- Research highlights: → Lipozyme TL-100L and Novozym 388 were immobilized onto micro porous polymeric matrix by both physical adsorption and covalent linking. → Immobilized enzymes were used for synthesis of fatty acid methyl esters by transesterification of canola oil and methanol using semi-continuous operation system. → According to chromatographic analysis, Lipase Lipozyme TL-100L resulted in the highest yield of methyl ester as 92%.

Characterisation of monoclonal antibodies for human luteinising hormone, and mapping of antigenic determinants on the hormone

International Nuclear Information System (INIS)

Soos, M.; Siddle, K.

1983-01-01

Twelve mouse monoclonal antibodies for human luteinising hormone were produced. The affinities varied from 4 X 10 7 to 1 X 10 10 l/mol. The specificity of each antibody was assessed by determining the relative reactivities with luteinising hormone, thyroid stimulating hormone, follicle stimulating hormone and chorionic gonadotrophin. Six antibodies bound to the α-subunit as shown by similar reactivity with all hormones, and the remainder to the β-subunit as shown by specificity for luteinising hormone. This latter group of antibodies cross-reacted only weakly with thyroid stimulating hormone (approximately 10%) and follicle stimulating hormone (approximately 3%). Three of these antibodies also showed low reactivity towards chorionic gonadotrophin (<10%), though the others did not (80-300%). The ability of different antibodies to bind simultaneously to luteinising hormone was examined and it was shown that several distinct antigenic determinants existed on both subunits. The characterisation of monoclonal binding sites is discussed in relation to the use of antibodies in two-site immunoradiometric assays. (Auth.)

Synthesis, characterization and application of lipase-conjugated citric acid-coated magnetic nanoparticles for ester synthesis using waste frying oil.

Science.gov (United States)

Patel, Unisha; Chauhan, Kishor; Gupte, Shilpa

2018-04-01

In the present work, magnetic nanoparticles (MNPs) were prepared by chemical precipitation of trivalent and divalent iron ions which were functionalized using citric acid. The bacterial isolate Staphylococcus epidermidis KX781317 was isolated from oil-contaminated site. The isolate produced lipase, which was purified and immobilized on magnetic nanoparticles (MNPs) for ester synthesis from waste frying oil (WFO). The characterization of MNPs employed conventional TEM, XRD and FTIR techniques. TEM analysis of MNPs showed the particle size in the range of 20-50 nm. FTIR spectra revealed the binding of citric acid to Fe 3 O 4 and lipase on citric acid-coated MNPs. The citric acid-coated MNPs and lipase-conjugated citric acid-coated MNPs had similar XRD patterns which indicate MNPs could preserve their magnetic properties. The maximum immobilization efficiency 98.21% of lipase-containing citric acid-coated MNPs was observed at ratio 10:1 of Cit-MNPs:lipase. The pH and temperature optima for lipase conjugated with Cit-MNPs were 7 and 35 °C, respectively. Isobutanol was found to be an effective solvent for ester synthesis and 1:2 ratio of oil:alcohol observed significant for ester formation. The ester formation was determined using TLC and the % yield of ester conversion was calculated. The rate of ester formation is directly proportional to the enzyme load. Formed esters were identified as isobutyl laurate ester and isobutyl myristate ester through GC-MS analysis.

Effect of Nelumbo nucifera Petal Extracts on Lipase, Adipogenesis, Adipolysis, and Central Receptors of Obesity

Directory of Open Access Journals (Sweden)

Chandrasekaran Chinampudur Velusami

2013-01-01

Full Text Available N. nucifera is one among the important medicinal plants assessed for its antiobesity action in various preclinical models. The present study was aimed at investigating the antiobesity effect of methanol and successive water extracts of petals of N. nucifera by studying its effect on adipogenesis, adipolysis, lipase, serotonin (5-HT2C, cannabinoid (CNR2, melanocyte concentrating hormone (MCHR1, and melanocortin (MC4R receptors. Both methanol and successive water extracts of N. nucifera petals had an effect on inhibition of lipid storage in adipocytes and on increasing lipolysis. N. nucifera petal methanol extract exhibited the concentration-dependent inhibitory effect on lipase activity with an IC50 value of 47 µg/mL. N. nucifera petal extracts showed evident agonist and antagonist activity towards 5-HT2C and CNR2 receptors, respectively, while it showed no effect towards MCHR1 and MC4R receptors. Overall, methanol extract of N. nucifera petals showed better activity than successive water extract.

Growth hormone (GH) binding and effects of GH analogs in transgenic mice

Energy Technology Data Exchange (ETDEWEB)

Bartke, A.; Steger, R.W. [Southern Illinois Univ., Carbondale, IL (United States); Turyn, D. [UBA-CONICET, Buenos Aires (Argentina)] [and others

1994-12-31

Overexpression of human (h) or bovine (b) growth hormone (GH) in transgenic mice is associated with marked (2- to 12-fold) and significant increase in hepatic binding of GH and prolactin (PRL). This is due to an increase in the number of GH and PRL receptors (GHR, PRLR) per mg of microsomal protein without changes in binding affinity. Comparison of results obtained in transgenic animals expressing bGH with a mouse metallothionein (MT) or a rat phosphoenolpyruvate carboxykinase (PEPCK) promoter suggests that effects of bGH on hepatic GHR and PRLR do not require GH overexpression during fetal life and, within the dose range tested, the effects on PRLR are not dose dependent. The increase in hepatic GHR was accompanied by significant increases in plasma GH-binding protein (GHBP) and in mean residence time of injected GH. Thus life-long elevation of peripheral GH levels alters the availability of both free GH and GHR. Site-directed in vitro mutagenesis was used to produce hGH and bGH analogs mutated within one of the sites involved in binding to GHR and PRLR. Mutating hGH to produce amino acid identity with bGH at Position 11, 18 (within Helix 1), 57, or 60 (within the loop between Helix 1 and 2) did not affect binding to GHR in vitro, or somatotropic activity in transgenic mice in vivo but reduced lactogenic activity in Nb{sub 2} cells by 22%-45%. Mutations of bGH designed to produce amino acid identity with hGH at one to four of the corresponding positions in the bGH molecule did not interfere with binding to GHR or somatotropic activity in vivo, and failed to produce significant binding to PRLR but resulted in alterations in the effects on the hypothalamic and anterior pituitary function in transgenic mice. Apparently region(s) outside the domains examined are essential for lactogenic activity of hGH, and different portions of the GH molecule are responsible for its diverse actions in vivo. 35 refs.

In silico identification of anthropogenic chemicals as ligands of zebrafish sex hormone binding globulin

International Nuclear Information System (INIS)

Thorsteinson, Nels; Ban, Fuqiang; Santos-Filho, Osvaldo; Tabaei, Seyed M.H.; Miguel-Queralt, Solange; Underhill, Caroline; Cherkasov, Artem; Hammond, Geoffrey L.

2009-01-01

Anthropogenic compounds with the capacity to interact with the steroid-binding site of sex hormone binding globulin (SHBG) pose health risks to humans and other vertebrates including fish. Building on studies of human SHBG, we have applied in silico drug discovery methods to identify potential binders for SHBG in zebrafish (Danio rerio) as a model aquatic organism. Computational methods, including; homology modeling, molecular dynamics simulations, virtual screening, and 3D QSAR analysis, successfully identified 6 non-steroidal substances from the ZINC chemical database that bind to zebrafish SHBG (zfSHBG) with low-micromolar to nanomolar affinities, as determined by a competitive ligand-binding assay. We also screened 80,000 commercial substances listed by the European Chemicals Bureau and Environment Canada, and 6 non-steroidal hits from this in silico screen were tested experimentally for zfSHBG binding. All 6 of these compounds displaced the [ 3 H]5α-dihydrotestosterone used as labeled ligand in the zfSHBG screening assay when tested at a 33 μM concentration, and 3 of them (hexestrol, 4-tert-octylcatechol, and dihydrobenzo(a)pyren-7(8H)-one) bind to zfSHBG in the micromolar range. The study demonstrates the feasibility of large-scale in silico screening of anthropogenic compounds that may disrupt or highjack functionally important protein:ligand interactions. Such studies could increase the awareness of hazards posed by existing commercial chemicals at relatively low cost

Biodegradable products by lipase biocatalysis.

Science.gov (United States)

Linko, Y Y; Lämsä, M; Wu, X; Uosukainen, E; Seppälä, J; Linko, P

1998-11-18

The interest in the applications of biocatalysis in organic syntheses has rapidly increased. In this context, lipases have recently become one of the most studied groups of enzymes. We have demonstrated that lipases can be used as biocatalyst in the production of useful biodegradable compounds. A number of examples are given. 1-Butyl oleate was produced by direct esterification of butanol and oleic acid to decrease the viscosity of biodiesel in winter use. Enzymic alcoholysis of vegetable oils without additional organic solvent has been little investigated. We have shown that a mixture of 2-ethyl-1-hexyl esters can be obtained in a good yield by enzymic transesterification from rapeseed oil fatty acids for use as a solvent. Trimethylolpropane esters were also similarly synthesized as lubricants. Finally, the discovery that lipases can also catalyze ester syntheses and transesterification reactions in organic solvent systems has opened up the possibility of enzyme catalyzed production of biodegradable polyesters. In direct polyesterification of 1,4-butanediol and sebacic acid, polyesters with a mass average molar mass of the order of 56,000 g mol-1 or higher, and a maximum molar mass of about 130,000 g mol-1 were also obtained by using lipase as biocatalyst. Finally, we have demonstrated that also aromatic polyesters can be synthesized by lipase biocatalysis, a higher than 50,000 g mol-1 mass average molar mass of poly(1,6-hexanediyl isophthalate) as an example.

Sex differences, endogenous sex-hormone hormones, sex-hormone binding globulin, and exogenous disruptors in diabetes and related metabolic outcomes.

Science.gov (United States)

Liu, Simin; Sun, Qi

2016-12-19

In assessing clinical and pathophysiological development of type 2 diabetes (T2D), the critical role of the sex steroids axis is underappreciated, particularly concerning the sex-specific relationships with many relevant cardiometabolic outcomes. In this issue of the Journal of Diabetes, we provide a comprehensive overview of these significant associations of germline variants in the genes governing the sex steroid pathways, plasma levels of steroid hormones, and sex hormone-binding globulin (SHBG) with T2D risk that have been observed in many clinical and high-quality large prospective cohorts of men and women across ethnic populations. Together, this body of evidence indicates that sex steroids and SHBG should be routinely incorporated into clinical characterization of T2D patients, particularly in screening prediabetic patients, such as those with metabolic syndrome, using plasma levels of SHBG. Given that several germline mutations in the SHBG gene have also been directly related to both plasma concentrations of SHBG and clinical manifestation of T2D, targeting signals in the sex steroid axis, particularly SHBG, may have significant utility in the prediction and treatment of T2D. Further, many of the environmental endocrine disrupting chemicals may exert their potential adverse effects on cardiometabolic outcomes via either estrogenic or androgenic signaling pathways, highlighting the importance of using the sex steroids and SHBG as important biochemical markers in both clinical and population studies in studying sex-specific mechanisms in the pathogenesis of T2D and its complications, as well as the need to equitably allocate resources in studying both men and women. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings

Energy Technology Data Exchange (ETDEWEB)

Batista, Karla A. [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Lopes, Flavio Marques [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Unidade Universitária de Ciências Exatas e Tecnológicas, Universidade Estadual de Goiás, Anápolis, GO (Brazil); Yamashita, Fabio [Departamento de Tecnologia de Alimentos e Medicamentos, Laboratório de Tecnologia, Universidade Estadual de Londrina, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil); Fernandes, Kátia Flávia, E-mail: katia@icb.ufg.br [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil)

2013-04-01

This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film.

Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings

International Nuclear Information System (INIS)

Batista, Karla A.; Lopes, Flavio Marques; Yamashita, Fabio; Fernandes, Kátia Flávia

2013-01-01

This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film

Rat lingual lipase: partial purification, hydrolytic properties, and comparison with pancreatic lipase.

Science.gov (United States)

Roberts, I M; Montgomery, R K; Carey, M C

1984-10-01

We have partially purified lingual lipase from the serous glands of rat tongue. With a combination of Triton X-100 extraction or Triton X-114 phase-separation techniques, Bio-Bead SM-2 treatment, dialysis, and gel filtration on Sephadex G-200 or Sephacryl S-300, we obtained a sparingly soluble lipid-free protein demonstrating hydrolytic activity against triglycerides and negligible phospholipase or cholesteryl esterase activities. Compared with homogenate, specific activities of the enzyme were enriched 3- to 5-fold prior to gel filtration and 10-fold after gel filtration. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration under denaturing conditions (6 M guanidine X HCl or 0.1% sodium dodecyl sulfate) revealed one major glycoprotein band with Mr approximately 50,000. Gel filtration of the active enzyme in 0.1% Triton X-100 gave an Mr approximately 270,000-300,000, suggesting extensive self-aggregation. With both tributyrin and triolein, the pH optimum of the purified enzyme was 4.0 and activity extended from pH 2.0 to 8.0. In contrast to purified human pancreatic lipase, lingual lipase hydrolyzed triglyceride emulsions and mixed micelles stabilized with both short-chain (dihexanoyl) and long-chain (egg) lecithin and were inhibited only slightly (18-25%) by micellar concentrations of two common bile salts, taurodeoxycholate and taurocholate. Our results suggest that the hydrolysis of dietary fat by lingual lipase may extend from the pharynx through the esophagus and stomach and into the upper small intestine.

Immobilization of lipase on sepabeads and its application in pentyl octanoate synthesis in a low aqueous system

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Knežević-Jugović Zorica D.

2008-01-01

Full Text Available The object of the study was to investigate the process conditions relevant for the pentyl octanoate production with the lipase from Candida rugosa immobilized on Sepabeads EC-EP carrier. This is an epoxide-containing commercial polymethacrylic carrier with suitable characteristics for enzyme immobilization. The immobilized lipase suitable for pentyl octanoate synthesis has been prepared by a direct lipase binding to polymers via their epoxide groups. The enzymatic activity was determined by both hydrolysis of olive oil in an aqueous system and esterification of n-pentanol with octanoic acid in a low aqueous system. The influence of several important reaction parameters such as temperature, initial water content, initial substrate molar ratio, enzyme loading and time of adding of molecular sieves in the system is carefully analyzed by means of an experimental design. Production of the ester was optimized and an ester production response equation was obtained, making it possible to predict ester yields from known values of the five main factors. Almost complete conversion (>99% of the substrate to ester could be realized, using lipase loading as low as 37 mg/g dry support and in a relatively short time (24 h at 45ºC, when high initial substrate molar ratio of 2.2 is used.

A genome-wide association meta-analysis of circulating sex hormone-binding globulin reveals multiple Loci implicated in sex steroid hormone regulation.

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Andrea D Coviello

Full Text Available Sex hormone-binding globulin (SHBG is a glycoprotein responsible for the transport and biologic availability of sex steroid hormones, primarily testosterone and estradiol. SHBG has been associated with chronic diseases including type 2 diabetes (T2D and with hormone-sensitive cancers such as breast and prostate cancer. We performed a genome-wide association study (GWAS meta-analysis of 21,791 individuals from 10 epidemiologic studies and validated these findings in 7,046 individuals in an additional six studies. We identified twelve genomic regions (SNPs associated with circulating SHBG concentrations. Loci near the identified SNPs included SHBG (rs12150660, 17p13.1, p = 1.8 × 10(-106, PRMT6 (rs17496332, 1p13.3, p = 1.4 × 10(-11, GCKR (rs780093, 2p23.3, p = 2.2 × 10(-16, ZBTB10 (rs440837, 8q21.13, p = 3.4 × 10(-09, JMJD1C (rs7910927, 10q21.3, p = 6.1 × 10(-35, SLCO1B1 (rs4149056, 12p12.1, p = 1.9 × 10(-08, NR2F2 (rs8023580, 15q26.2, p = 8.3 × 10(-12, ZNF652 (rs2411984, 17q21.32, p = 3.5 × 10(-14, TDGF3 (rs1573036, Xq22.3, p = 4.1 × 10(-14, LHCGR (rs10454142, 2p16.3, p = 1.3 × 10(-07, BAIAP2L1 (rs3779195, 7q21.3, p = 2.7 × 10(-08, and UGT2B15 (rs293428, 4q13.2, p = 5.5 × 10(-06. These genes encompass multiple biologic pathways, including hepatic function, lipid metabolism, carbohydrate metabolism and T2D, androgen and estrogen receptor function, epigenetic effects, and the biology of sex steroid hormone-responsive cancers including breast and prostate cancer. We found evidence of sex-differentiated genetic influences on SHBG. In a sex-specific GWAS, the loci 4q13.2-UGT2B15 was significant in men only (men p = 2.5 × 10(-08, women p = 0.66, heterogeneity p = 0.003. Additionally, three loci showed strong sex-differentiated effects: 17p13.1-SHBG and Xq22.3-TDGF3 were stronger in men, whereas 8q21.12-ZBTB10 was stronger in women. Conditional analyses identified additional signals at the SHBG gene that together almost double the proportion

Analysis and functional characterization of sequence variations in ligand binding domain of thyroid hormone receptors in autism spectrum disorder (ASD) patients.

Science.gov (United States)

Kalikiri, Mahesh Kumar; Mamidala, Madhu Poornima; Rao, Ananth N; Rajesh, Vidya

2017-12-01

Autism spectrum disorder (ASD) is a neuro developmental disorder, reported to be on a rise in the past two decades. Thyroid hormone-T3 plays an important role in early embryonic and central nervous system development. T3 mediates its function by binding to thyroid hormone receptors, TRα and TRβ. Alterations in T3 levels and thyroid receptor mutations have been earlier implicated in neuropsychiatric disorders and have been linked to environmental toxins. Limited reports from earlier studies have shown the effectiveness of T3 treatment with promising results in children with ASD and that the thyroid hormone levels in these children was also normal. This necessitates the need to explore the genetic variations in the components of the thyroid hormone pathway in ASD children. To achieve this objective, we performed genetic analysis of ligand binding domain of THRA and THRB receptor genes in 30 ASD subjects and in age matched controls from India. Our study for the first time reports novel single nucleotide polymorphisms in the THRA and THRB receptor genes of ASD individuals. Autism Res 2017, 10: 1919-1928. ©2017 International Society for Autism Research, Wiley Periodicals, Inc. Thyroid hormone (T3) and thyroid receptors (TRα and TRβ) are the major components of the thyroid hormone pathway. The link between thyroid pathway and neuronal development is proven in clinical medicine. Since the thyroid hormone levels in Autistic children are normal, variations in their receptors needs to be explored. To achieve this objective, changes in THRA and THRB receptor genes was studied in 30 ASD and normal children from India. The impact of some of these mutations on receptor function was also studied. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Catalytic Properties of Lipase Extracts from Aspergillus niger

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Cintia M. Romero

2006-01-01

Full Text Available Screening of lipolytic strains using Rhodamine-B/olive oil plate technique allowed the selection of Aspergillus niger MYA 135. Lipase production in submerged culture containing 2 % olive oil was enhanced by more than 50 % compared to basal cultural conditions. Optimal catalytic conditions for olive oil-induced lipase were pH=6.5 and 30–35 °C. These values were shifted to the acid region (4.0–6.5 and 35–37 °C when lipase extract was produced under basal conditions. Slight changes of the residual lipase activity against the pH were found. However, preincubation at either 37 or 40 °C caused an increase in the olive oil-inducible lipolytic activity. On the contrary, lipase residual activity decreases in the 30–55 °C range when it was produced in basal medium. Lipolytic extracts were almost not deactivated in presence of 50 % water-miscible organic solvents. However, water-immiscible aliphatic solvents reduced the lipase activity between 20 and 80 %.

Isolation and analysis of lipase-overproducing mutants of Serratia marcescens.

Science.gov (United States)

Kawai, E; Akatsuka, H; Sakurai, N; Idei, A; Matsumae, H; Shibatani, T; Komatsubara, S; Omori, K

2001-01-01

We have isolated a lipase-overproducing mutant, GE14, from Serratia marcescens 8000 after three rounds of N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. The mutant GE14 produced 95 kU/ml of extracellular lipase in the lipase medium, which was about threefold higher than that of produced by the original strain 8000. Enzymatic characteristics including specific activity of purified lipases from culture supernatants of GE14 and 8000 were almost same. The lipase gene (lipA) of GE14 contained two base substitutions; one in the promoter region and another in the N-terminal region of the lipA gene without an amino acid substitution. Promoter analysis using lipA-lacZ fusion plasmids revealed that these substitutions were responsible for the increase in the lipA expression level, independently. In contrast, no base substitution was found in the genes encoding the lipase secretion device, the Lip system. In addition, the genes coding for metalloprotease and the cell surface layer protein which are both secreted through the Lip system and associated with extracellular lipase production, also contained no base substitution. The strain GE14 carrying a high-copy-number lipA plasmid produced a larger amount of the extracellular lipase than the recombinant strains of 8000 and other mutants also did, indicating that GE14 was not only a lipase-overproducing strain, but also an advantageous host strain for overproducing the lipase by a recombinant DNA technique. These results suggest that the lipase-overproducing mutant GE14 and its recombinant strains are promising candidates for the industrial production of the S. marcescens lipase.

Glycolipid Biosurfactants Activate, Dimerize, and Stabilize Thermomyces lanuginosus Lipase in a pH-Dependent Fashion.

Science.gov (United States)

Madsen, Jens Kvist; Kaspersen, Jørn Døvling; Andersen, Camilla Bertel; Nedergaard Pedersen, Jannik; Andersen, Kell Kleiner; Pedersen, Jan Skov; Otzen, Daniel E

2017-08-15

We present a study of the interactions between the lipase from Thermomyces lanuginosus (TlL) and the two microbially produced biosurfactants (BSs), rhamnolipid (RL) and sophorolipid (SL). Both RL and SL are glycolipids; however, RL is anionic, while SL is a mixture of anionic and non-ionic species. We investigate the interactions of RL and SL with TlL at pH 6 and 8 and observe different effects at the two pH values. At pH 8, neither RL nor SL had any major effect on TlL stability or activity. At pH 6, in contrast, both surfactants increase TlL's thermal stability and fluorescence and activity measurements indicate interfacial activation of TlL, resulting in 3- and 6-fold improved activity in SL and RL, respectively. Nevertheless, isothermal titration calorimetry reveals binding of only a few BS molecules per lipase. Size-exclusion chromatography and small-angle X-ray scattering suggest formation of TlL dimers with binding of small amounts of either RL or SL at the dimeric interface, forming an elongated complex. We conclude that RL and SL are compatible with TlL and constitute promising green alternatives to traditional surfactants.

Stability of immobilized candida sp. 99-125 Lipase for biodiesel production

Energy Technology Data Exchange (ETDEWEB)

Lu, J. [Beijing Bioprocess Key Laboratory, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing (China); Bioengineering Department, Zhengzhou University, Zhengzhou (China); Deng, L.; Nie, K.; Wang, F.; Tan, T. [Beijing Bioprocess Key Laboratory, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing (China)

2012-12-15

The stability of the immobilized lipase from Candida sp. 99-125 during biodiesel production was investigated. The lipase was separately incubated in the presence of various reaction components such as soybean oil, oleic acid methyl ester, n-hexane, water, methanol, and glycerol, or the lipase was stored at 60, 80, 100 and 120 C. Thereafter the residual lipase activity was determined by methanolysis reaction. The results showed that the lipase was rather stable in the reaction media, except for methanol and glycerol. The stability study performed in a reciprocal shaker indicated that enzyme desorption from the immobilized lipase mainly contributed to the lipase inactivation in the water system. So the methanol and glycerol contents should be controlled more precisely to avoid lipase inactivation, and the immobilization method should be improved with regard to lipase desorption. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

α-Eleostearic acid-containing triglycerides for a continuous assay to determine lipase sn-1 and sn-3 regio-preference.

Science.gov (United States)

El Alaoui, Meddy; Soulère, Laurent; Noiriel, Alexandre; Queneau, Yves; Abousalham, Abdelkarim

2017-08-01

Lipases are essentially described as sn-1 and sn-3 regio-selective. Actually few methods are available to measure this lipase regio-selectivity, moreover they require chiral chromatography analysis or specific derivations which are discontinuous and time consuming. In this study we describe a new, convenient, sensitive and continuous spectrophotometric method to screen lipases regio-selectivity using synthetic triglycerides (TG) containing α-eleostearic acid (9Z, 11E, 13E-octadecatrienoic acid) either at the sn-1 position [1-α-eleostearoyl-2,3-octadecyl-sn-glycerol (sn-EOO)] or at the sn-3 position [1,2-octadecyl-3-α-eleostearoyl-sn-glycerol (sn-OOE)] and coated onto the wells of microtiter plates. A non-hydrolysable ether bond, with a non UV-absorbing alkyl chain, was introduced at the other sn positions to prevent acyl chain migration during TG synthesis or lipolysis. The synthesis of TG containing α-eleostearic acid was performed from S-glycidol in six steps to obtain sn-EOO and in five steps to sn-OOE. The α-eleostearic acid conjugated triene constitutes an intrinsic chromophore and, consequently, confers the strong UV absorption properties of this free fatty acid as well as of the TG harboring it. The lipase activity on coated sn-EOO or sn-OOE was measured by the increase in the absorbance at 272nm due to the transition of α-eleostearic acid from the adsorbed to the soluble state. Human and porcine pancreatic lipases, guinea pig pancreatic lipase related protein 2, Thermomyces lanuginosus lipase, Candida antarctica lipase A and Candida antarctica lipase B were all used to validate the assay. This continuous high-throughput screening method could determine directly without any processes after lipolysis the regio-selectivity of various lipases. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular characterization of a proteolysis-resistant lipase from Bacillus pumilus SG2

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R. Sangeetha

2014-06-01

Full Text Available Proteolysis-resistant lipases can be well exploited by industrial processes which employ both lipase and protease as biocatalysts. A proteolysis resistant lipase from Bacillus pumilus SG2 was isolated, purified and characterized earlier. The lipase was resistant to native and commercial proteases. In the present work, we have characterized the lip gene which encodes the proteolysis-resistant lipase from Bacillus pumilus SG2. The parameters and structural details of lipase were analysed. The lip gene consisted of 650 bp. The experimental molecular weight of SG2 lipase was nearly double that of its theoretical molecular weight, thus suggesting the existence of the functional lipase as a covalent dimer. The proteolytic cleavage sites of the lipase would have been made inaccessible by dimerisation, thus rendering the lipase resistant to protease.

Applications of immobilized Thermomyces lanuginosa lipase in interesterification

DEFF Research Database (Denmark)

Yang, Tiankui; Fruekilde, Maj-Britt; Xu, Xuebing

2003-01-01

(RSM). Thermomyces lanuginosa lipase had an activity similar to that of immobilized Rhizomucor miehei lipase (Lipozyme RM IM) in the glycerolysis of sunflower oil, but the former had higher activity at a low reaction temperature (5degreesC). Thermomyces lanuginosa lipase was found to have much lower...... catalytic activity than Lipozyme RM IM in the acidolysis of sunflower oil with caprylic acid. However, the activity of T. lanuginosa lipase was only slightly lower than that of Lipozyme RM IM in the ester-ester exchange between tripalmitin (PPP) and the ethyl esters of EPA and DHA (EE). For this reason...

Altering the activation mechanism in Thermomyces lanuginosus lipase

DEFF Research Database (Denmark)

Skjold-Jørgensen, Jakob; Vind, Jesper; Svendsen, Allan

2014-01-01

It is shown by rational site-directed mutagenesis of the lid region in Thermomyces lanuginosus lipase that it is possible to generate lipase variants with attractive features, e.g., high lipase activity, fast activation at the lipid interface, ability to act on water-soluble substrates......, and enhanced calcium independence. The rational design was based on the lid residue composition in Aspergillus niger ferulic acid esterase (FAEA). Five constructs included lipase variants containing the full FAEA lid, a FAEA-like lid, an intermediate lid of FAEA and TlL character, and the entire lid region...... from Aspergillus terreus lipase (AtL). To investigate an altered activation mechanism for each variant compared to that of TlL, a combination of activity- and spectroscopic-based measurements were applied. The engineered variant with a lid from AtL displayed interfacial activation comparable...

Butyl acetate synthesis using immobilized lipase in calcium alginate beads

International Nuclear Information System (INIS)

Mohd Zulkhairi Abdul Rahim; Lee, Pat M.; Lee, Kong H.

2008-01-01

The esterification reaction of acetic acid and n-butanol using immobilized lipase encapsulated in calcium alginate beads (Lipase - CAB) and in chitosan coated calcium alginate beads (Lipase-CCAB) in n-hexane under mild reaction conditions were studied. Effects of temperature and substrate concentration (acetic acid and n-butanol) using Lipase - CAB, Lipase - CCAB and free lipase on the esterification reaction and their thermal stability towards esterification reaction were investigated. Results of temperature studies showed that the butyl acetate conversion increased with increase of temperature and reached the highest yield of about 70% around 50 degree Celsius for both immobilized systems but the yield of product catalyzed by free enzyme decreased as temperature was increased. Thermal stabilities studies showed that the Lipase-CCAB and Lipase-CAB were stable throughout the temperature range of 30-60 degree Celsius. However, free lipase became less stable at temperatures higher than 50 degree Celsius. The substrates, n-butanol and acetic acid exerted different effects on the esterification reaction and the reaction was favoured by higher acetic acid concentration than butanol. Kinetics parameters, Km and Vmax values for both substrates and the specific activities of the three enzyme system were also determined. The beads morphology was examined using SEM. Batch-wise operational stability studies for both immobilized systems demonstrated that the immobilized lipase performed better in the batch wise reactor system than the continuous bioreactor system and that the immobilized lipase remained active for at least 5 cycles of batch wise esterification reactions. (author)

Localization of gonadotropin binding sites in human ovarian neoplasms

International Nuclear Information System (INIS)

Nakano, R.; Kitayama, S.; Yamoto, M.; Shima, K.; Ooshima, A.

1989-01-01

The binding of human luteinizing hormone and human follicle-stimulating hormone to ovarian tumor biopsy specimens from 29 patients was analyzed. The binding sites for human luteinizing hormone were demonstrated in one tumor of epithelial origin (mucinous cystadenoma) and in one of sex cord-stromal origin (theca cell tumor). The binding sites for human follicle-stimulating hormone were found in three tumors of epithelial origin (serous cystadenoma and mucinous cystadenoma) and in two of sex cord-stromal origin (theca cell tumor and theca-granulosa cell tumor). The surface-binding autoradiographic study revealed that the binding sites for gonadotropins were localized in the stromal tissue. The results suggest that gonadotropic hormones may play a role in the growth and differentiation of a certain type of human ovarian neoplasms

Gastric lipase: localization of the enzyme in the stomach

International Nuclear Information System (INIS)

DeNigris, S.J.; Hamosh, M.; Hamosh, P.; Kasbekar, D.K.

1986-01-01

Isolated gastric glands prepared from human and rabbit stomach secrete lipase in response to secretagogues. They have investigated the localization of this enzyme in three species (rabbit, baboon, guinea pig). Gastric mucosa was sampled from the cardia (C), fundus-smooth (FS), fundus-ruggae (FR) and the antral area (A). Lipase activity was measured in mucosal homogenates using 3 H-triolein as substrate and is expressed in units (U) = nmols free fatty acid released/min/mg wet weight. The localization of lipase is compared with that of pepsin (measured by hydrolysis of 2% hemoglobin at pH 1.8 and expressed in I.U.). Lipase is localized in a well defined area in the rabbit and is diffusely distributed in both guinea pig and baboon. The distribution of lipase and pepsin containing cells differs in all three species. The cellular origin of gastric lipase remains to be determined

Differential effect of combined lipase deficiency (cld/cld) on human hepatic lipase and lipoprotein lipase secretion.

Science.gov (United States)

Boedeker, J C; Doolittle, M H; White, A L

2001-11-01

Combined lipase deficiency (cld) is a recessively inherited disorder in mice associated with a deficiency of LPL and hepatic lipase (HL) activity. LPL is synthesized in cld tissues but is retained in the endoplasmic reticulum (ER), whereas mouse HL (mHL) is secreted but inactive. In this study we investigated the effect of cld on the secretion of human HL (hHL) protein mass and activity. Differentiated liver cell lines were derived from cld mice and their normal heterozygous (het) littermates by transformation of hepatocytes with SV40 large T antigen. After transient transfection with lipase expression constructs, secretion of hLPL activity from cld cells was only 12% of that from het cells. In contrast, the rate of secretion of hHL activity and protein mass per unit of expressed hHL mRNA was identical for the two cell lines. An intermediate effect was observed for mHL, with a 46% reduction in secretion of activity from cld cells. The ER glucosidase inhibitor, castanospermine, decreased secretion of both hLPL and hHL from het cells by approximately 70%, but by only approximately 45% from cld cells. This is consistent with data suggesting that cld may result from a reduced concentration of the ER chaperone calnexin. In conclusion, our results demonstrate a differential effect of cld on hLPL, mHL, and hHL secretion, suggesting differential requirements for activation and exit of the enzymes from the ER.

Lipase - Catalyzed glycerolysis of sunflower oil to produce partial glycerides.

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Zaher, F. A.

1998-12-01

Full Text Available Partial glycerides were prepared by glycerolysis of sunflower oil in presence of lipase enzyme as catalyst. Six lipases of different origins were used and compared for their catalytic activity. These include Chromobacterium lipase, pancreatic lipase, Rhizopus arrhizus lipase, lyophilized lipase (plant lipase in addition to two lipase preparations derived from Rhizopus japonicas; Lilipase A-10 and Lilipase B-2. Chromobacterium lipase was found to be the most active as glycerolysis catalyst whereas lyophilized lipase; a plant preparation from wheat germ was the least active. The results have also shown that the lipase type affects also the product polarity and hence its field of application as a food emulsifier. Less polar products can be obtained using Chromobacterium lipase whereas the more polar ones using a fungal lipase preparation «Lipase A-10». The product polarity is also influenced by the process temperature but the mode of its effect is different for different lipases.

Se prepararon glicéridos parciales mediante glicerolisis de aceite de girasol en presencia de lipasa como catalizador. Seis lipasas de orígenes diferentes se utilizaron y compararon en función de su actividad catalítica. Estas incluyeron lipasa de Chromobacterium, lipasa pancreática, lipasa de Rhizopus arrhizus, lipasa liofilizada (lipasa vegetal además de dos preparaciones de lipasa derivadas de Rhizopus japonicus: lilipase A-10 y lilipase B-2. Se encontró que la lipasa de Chromobacterium fue la más activa como catalizador en la glicerolisis mientras que la lipasa liofilizada, preparación vegetal a partir de germen de trigo, fue la menos activa. Los resultados mostraron que los tipos de lipasa afectan también a la polaridad de los productos y por tanto a los rendimientos en su aplicación como emulsificantes alimentarios. Los productos menos polares pueden obtenerse usando lipasa de

Association of Serum Testosterone and Sex Hormone Binding Globulin Levels in Females with Acne Based on its Severity

International Nuclear Information System (INIS)

Kiayani, A. J.; Rehman, R. U.

2016-01-01

Background: Androgens are involved in the development of acne. The aim of this study was to find out if there was an association of serum testosterone and sex hormone binding globulin (SHBG) in females with acne based on its severity. Methods: It was a cross sectional study, conducted in Dermatology unit of Fauji Foundation Hospital (FFH), Rawalpindi. Duration of study was eight months. Adult females with acne were enrolled in the study. Patients were categorized into minor, mild, moderate groups. Blood samples were taken for serum testosterone and SHBG. Results: Five hundred and thirty-one adult female were enrolled into the study. The mean age was 21.49±4.73 years. Acne was graded as minor in 78 (14.7 percent) cases, mild in 248 (46.7 percent) and moderate in 205 (38.6 percent). There was no statistically significant relationship between the levels of serum testosterone (p=0.776) and SHBG (p=0.711) with acne severity. Conclusion: There was no association of serum testosterone and sex hormone binding globulin levels in females with acne based on its severity. (author)

Molecular characterization of a genetic variant of the steroid hormone-binding globulin gene in heterozygous subjects

Energy Technology Data Exchange (ETDEWEB)

Hardy, D.O.; Catterall, J.F. [Population Council, New York, NY (United States); Carino, C. [Instituto National de la Nutricion, Mexico City, MX (United States)] [and others

1995-04-01

Steroid hormone-binding globulin in human serum displays different isoelectric focusing (IEF) patterns among individuals, suggesting genetic variation in the gene for this extracellular steroid carrier protein. Analysis of allele frequencies and family studies suggested the existence of two codominant alleles of the gene. Subsequent determination of the molecular basis of a variant of the gene was carried out using DNA from homozygous individuals from a single Belgian family. It was of interest to characterize other variant individuals to determine whether all variants identified by IEF phenotyping were caused by the same mutation or whether other mutations occurred in the gene in different populations. Previous studies identified Mexican subjects who were heterozygous for the variant IEF phenotype. Denaturing gradient gel electrophoresis was used to localize the mutation in these subjects and to purify the variant allele for DNA sequence analysis. The results show that the mutation in this population is identical to that identified in the Belgian family, and no other mutations were detected in the gene. These data represent the first analysis of steroid hormone-binding globulin gene variation in heterozygous subjects and further support the conclusion of biallelism of the gene worldwide. 11 refs., 2 figs., 1 tab.

Seed lipases: sources, applications and properties - a review

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M. Barros

2010-03-01

Full Text Available This paper provides an overview regarding the main aspects of seed lipases, such as the reactions catalyzed, physiological functions, specificities, sources and applications. Lipases are ubiquitous in nature and are produced by several plants, animals and microorganisms. These enzymes exhibit several very interesting features, such as low cost and easy purification, which make their commercial exploitation as industrial enzymes a potentially attractive alternative. The applications of lipases in food, detergents, oils and fats, medicines and fine chemistry, effluent treatment, biodiesel production and in the cellulose pulp industry, as well as the main sources of oilseed and cereal seed lipases, are reviewed.

Structural characterization of MAPLE deposited lipase biofilm

Energy Technology Data Exchange (ETDEWEB)

Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Ausanio, Giovanni; Bloisi, Francesco [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Calabria, Raffaela [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Califano, Valeria, E-mail: v.califano@im.cnr.it [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Massoli, Patrizio [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Vicari, Luciano R.M. [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy)

2014-11-30

Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase.

Growth hormone insensitivity syndrome: A sensitive approach

Directory of Open Access Journals (Sweden)

Soumik Goswami

2012-01-01

Full Text Available Patients with Growth Hormone Insensitivity have characteristic phenotypic features and severe short stature. The underlying basis are mutations in the growth hormone receptor gene which gives rise to a characteristic hormonal profile. Although a scoring system has been devised for the diagnosis of this disorder, it has not been indisputably validated. The massive expense incurred in the diagnosis and treatment of this condition with suboptimal therapeutic response necessitates a judicious approach in this regard in our country.

Competitive binding thyroid assay with improved bound-free separation step

International Nuclear Information System (INIS)

1979-01-01

A competitive binding assay is described for serum thyroid hormone using 125 I-labelled thyroid hormone and exogenous thyroid hormone binding protein. The unbound thyroid hormone is separated from thyroid hormone bound to thyroid hormone binding protein using an intermediate base anion exchange resin. This resin comprises tertiary and quaternary amine groups on a polyalkyleneamine lattice and is compressed with microcrystalline cellulose in a tablet form. The assay technique of the present invention employing an intermediate base anion resin was found to give superior results compared with alternative assay techniques used in serum thyroid hormone estimation. (UK)

Thyroid hormone signaling in the hypothalamus

NARCIS (Netherlands)

Alkemade, Anneke; Visser, Theo J.; Fliers, Eric

2008-01-01

PURPOSE OF REVIEW: Proper thyroid hormone signaling is essential for brain development and adult brain function. Signaling can be disrupted at many levels due to altered thyroid hormone secretion, conversion or thyroid hormone receptor binding. RECENT FINDINGS: Mutated genes involved in thyroid

Inhibition of lipases from Chromobacterium viscosum and Rhizopus oryzae by tetrahydrolipstatin.

Science.gov (United States)

Potthoff, A P; Haalck, L; Spener, F

1998-01-15

Tetrahydrolipstatin is known as an inhibitor for pancreatic lipase but not for microbial lipases. In this paper we demonstrate that in the presence of water-insoluble substrates like tributyrin or olive oil, tetrahydrolipstatin inhibits the lipases of Chromobacterium viscosum and Rhizopus oryzae, although with different potency. In contrast to porcine pancreatic lipase, which forms an irreversible and covalent enzyme-inhibitor complex with tetrahydrolipstatin, the inhibition of the microbial lipases is reversible as the inhibitor can be removed from the enzyme-inhibitor complex by solvent extraction. Moreover, after inhibition of Chromobacterium viscosum lipase tetrahydrolipstatin remains chemically unchanged.

Extended and structurally supported insights into extracellular hormone binding, signal transduction and organization of the thyrotropin receptor.

Directory of Open Access Journals (Sweden)

Gerd Krause

Full Text Available The hormone thyrotropin (TSH and its receptor (TSHR are crucial for the growth and function of the thyroid gland. The TSHR is evolutionary linked with the receptors of follitropin (FSHR and lutropin/choriogonadotropin (LHR and their sequences and structures are similar. The extracellular region of TSHR contains more than 350 amino acids and binds hormone and antibodies. Several important questions related to functions and mechanisms of TSHR are still not comprehensively understood. One major reason for these open questions is the lack of any structural information about the extracellular segment of TSHR that connects the N-terminal leucine-rich repeat domain (LRRD with the transmembrane helix (TMH 1, the hinge region. It has been shown experimentally that this segment is important for fine tuning of signaling and ligand interactions. A new crystal structure containing most of the extracellular hFSHR region in complex with hFSH has recently been published. Now, we have applied these new structural insights to the homologous TSHR and have generated a structural model of the TSHR LRRD/hinge-region/TSH complex. This structural model is combined and evaluated with experimental data including hormone binding (bTSH, hTSH, thyrostimulin, super-agonistic effects, antibody interactions and signaling regulation. These studies and consideration of significant and non-significant amino acids have led to a new description of mechanisms at the TSHR, including ligand-induced displacements of specific hinge region fragments. This event triggers conformational changes at a convergent center of the LRRD and the hinge region, activating an "intramolecular agonistic unit" close to the transmembrane domain.

Extended and structurally supported insights into extracellular hormone binding, signal transduction and organization of the thyrotropin receptor.

Science.gov (United States)

Krause, Gerd; Kreuchwig, Annika; Kleinau, Gunnar

2012-01-01

The hormone thyrotropin (TSH) and its receptor (TSHR) are crucial for the growth and function of the thyroid gland. The TSHR is evolutionary linked with the receptors of follitropin (FSHR) and lutropin/choriogonadotropin (LHR) and their sequences and structures are similar. The extracellular region of TSHR contains more than 350 amino acids and binds hormone and antibodies. Several important questions related to functions and mechanisms of TSHR are still not comprehensively understood. One major reason for these open questions is the lack of any structural information about the extracellular segment of TSHR that connects the N-terminal leucine-rich repeat domain (LRRD) with the transmembrane helix (TMH) 1, the hinge region. It has been shown experimentally that this segment is important for fine tuning of signaling and ligand interactions. A new crystal structure containing most of the extracellular hFSHR region in complex with hFSH has recently been published. Now, we have applied these new structural insights to the homologous TSHR and have generated a structural model of the TSHR LRRD/hinge-region/TSH complex. This structural model is combined and evaluated with experimental data including hormone binding (bTSH, hTSH, thyrostimulin), super-agonistic effects, antibody interactions and signaling regulation. These studies and consideration of significant and non-significant amino acids have led to a new description of mechanisms at the TSHR, including ligand-induced displacements of specific hinge region fragments. This event triggers conformational changes at a convergent center of the LRRD and the hinge region, activating an "intramolecular agonistic unit" close to the transmembrane domain.

Lipase A gene transcription in Pseudomonas alcaligenes is under control of RNA polymerase s54 and response regulator LipR

NARCIS (Netherlands)

Krzeslak, Joanna; Papaioannou, Evelina; van Merkerk, Ronald; Paal, Krisztina A.; Bischoff, Rainer; Cool, Robbert H.; Quax, Wim J.

Initial analysis has shown that the transcription of the Pseudomonas alcaligenes lipA gene, which encodes an extracellular lipase, is governed by the LipQR two-component system consisting of sensor kinase LipQ and DNA-binding regulator LipR. This study further analyzes lipA gene expression and

Changes in serum concentrations of growth hormone, insulin, insulin-like growth factor and insulin-like growth factor-binding proteins 1 and 3 and urinary growth hormone excretion during the menstrual cycle

DEFF Research Database (Denmark)

Juul, A; Scheike, Thomas Harder; Pedersen, A T

1997-01-01

Few studies exist on the physiological changes in the concentrations of growth hormone (GH), insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) within the menstrual cycle, and some controversy remains. We therefore decided to study the impact of endogenous sex steroids on the GH-I...

21 CFR 184.1420 - Lipase enzyme preparation derived from Rhizopus niveus.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lipase enzyme preparation derived from Rhizopus... GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1420 Lipase enzyme preparation derived from Rhizopus niveus. (a) Lipase enzyme preparation contains lipase enzyme (CAS Reg. No...

Primary and secondary structural determinants in the receptor binding sequence β-(38-57) from human luteinizing hormone

International Nuclear Information System (INIS)

Keutmann, H.T.; Charlesworth, M.C.; Kitzmann, K.; Mason, K.A.; Johnson, L.; Ryan, R.J.

1988-01-01

The intercysteine loop sequence 38-57 in the β subunit has been shown to be a determinant for expression of biological activity in human lutropin (hLH) and choriogonadotropin (hCG). Together with other sequences, the 38-57 region may contribute to a multicomponent receptor binding domain in hLH/hCG. Because the structural features influencing activity in this important region are not easy to evaluate in the full-length subunit, the authors have used analogues of hLHβ-(38-57) prepared by solid-phase synthesis. The peptides were tested for inhibition of 125 I-labeled hCG binding to rat ovarian membrane receptors. Secondary structure was analyzed by circular dichroism (CD) and by reactivity with antibodies to the native 38-57 peptide. An analogue lacking the 38-57 disulfide linkage retained 20% receptor binding and full immunoreactivity. Far-ultraviolet CD profiles were essentially identical with those of the disulfide-intact peptide; a transition from 10% to 30% α-helix in 90% trifluoroethanol was characteristic of both. The peptide thus appears not to require the disulfide bridge to retain a looped conformation with amphipathic secondary structure. An essential positive charge at position 43 was shown by complete loss of activity upon substitution of Asp or Ala for the Arg found in all known species of LH. These results indicate that the 38-57 sequence is a relatively rigid and structurally autonomous region, not merely a series of residues constrained passively into a loop by a disulfide linkage. It includes segments of ordered structure, probably including both amphipathic helical and turn sequences. Evidence from studies of other hormones suggests that this region may be important to binding and specificity in the glycoprotein hormones as a group

Production of lipase free of citrinin by Penicillium citrinum.

Science.gov (United States)

Pimentel, M C; Melo, E H; Lima Filho, J L; Durán, N

1996-02-01

Lipase (Glycerol ester hydrolase E.G. 3.1.1.3) from a Brazilian strain of Penicillium citrinum free of the mycotoxin citrinin has been investigated. Citrinin production was inhibited by using culture medium containing olive oil, soybean oil and corn oil as carbon sources. Potassium concentration and pH play an important role in citrinin production. Potassium concentration lower than 30 mM and pH below 4.5 inhibited the mycotoxin production. P. citrinum produced lipase free of extraneous proteins and citrinin when cultured using, as nitrogen source, ammonium sulphate (lipase activity of 7.88 U/mg) and yeast extract (lipase activity of 4.95 U/mg) with olive oil as carbon source. This data is relevant to the larger scale production of lipases for food technology applications, from Penicillium citrinum.

Engineering Lipases: walking the fine line between activity and stability

Science.gov (United States)

Dasetty, Siva; Blenner, Mark A.; Sarupria, Sapna

2017-11-01

Lipases are enzymes that hydrolyze lipids and have several industrial applications. There is a tremendous effort in engineering the activity, specificity and stability of lipases to render them functional in a variety of environmental conditions. In this review, we discuss the recent experimental and simulation studies focused on engineering lipases. Experimentally, mutagenesis studies have demonstrated that the activity, stability, and specificity of lipases can be modulated by mutations. It has been particularly challenging however, to elucidate the underlying mechanisms through which these mutations affect the lipase properties. We summarize results from experiments and molecular simulations highlighting the emerging picture to this end. We end the review with suggestions for future research which underscores the delicate balance of various facets in the lipase that affect their activity and stability necessitating the consideration of the enzyme as a network of interactions.

Study of enzymatic reactors with microencapsulated lipase. Doctoral thesis. Estudo de reactores enzimaticos com lipase microencapsulada

Energy Technology Data Exchange (ETDEWEB)

de Franca Teixeira dos Prazeres, D.M.

1992-10-01

The work reports the development of a membrane reactor for the hydrolysis of triglycerides catalyzed by lipase B from Chromobacterium viscosum in AOT/isooctane reversed miceller system. In a preliminary phase the potential of the organic system was evaluated with comparative studies on the activity and stability of lipase B in aqueous media (emulsion) and in the alternative miceller media. A tubular ceramic membrane reactor with recirculation was selected for the olive oil hydrolysis in a reversed miceller system. The influence of the hydration degree, recirculation rate, AOT, olive oil and lipase concentration in the operation of the reactor were investigated in a batch mode. The hydration degree was identified as a critical parameter due to its influence in the separation process and in the kinetics of the reaction.

TSH, thyroid hormones and nuclear-binding of T3 in mononuclear blood cells from obese and non-obese women

DEFF Research Database (Denmark)

Matzen, L E; Kvetny, J; Pedersen, K K

1989-01-01

The specific nuclear-binding of T3 (NBT3) in mononuclear blood cells, and the concentrations of TSH, thyroid hormones, and binding proteins were measured after overnight fasting in 12 obese and in 14 non-obese women, none of the subjects were taking any medicine. The concentrations of TSH and free...... plus bound-T3 (TT3) were significantly higher in the obese (p less than 0.05), concentrations of T4 and binding proteins did not differ. The NBT3 was significantly lower in the obese women; the maximal binding capacity (MBC) was 34.5 +/- 11.6 fmol/mg DNA in the obese subjects and 50.0 +/- 11.6 fmol....../mg DNA in the non-obese subjects (p less than 0.02). The binding affinities did not differ. We have previously shown that increasing T3 concentrations within the physiological range down-regulates NBT3. Therefore, the reduced NBT3 in the obese women was probably secondary to the increased TT3...

Thyroid hormone antibodies and Hashimoto's thyroiditis in mongrel dogs

Energy Technology Data Exchange (ETDEWEB)

Rajatanavin, R.; Fang, S.L.; Pino, S.; Laurberg, P.; Braverman, L.E.; Smith, M.; Bullock, L.P.

1989-05-01

Abnormally elevated serum T3 concentrations measured by RIA were observed in 19 clinically euthyroid or hypothyroid mongrel dogs. The serum T4 concentrations in these sera were low, normal, or high. Measurement of the intensity of thyroid hormone binding to serum proteins was determined by equilibrium dialysis. A marked decrease in the percent free T3 was observed in these abnormal sera. Polyacrylamide gel electrophoresis, pH 7.4, of normal dog serum enriched with tracer /sup 125/I-labeled thyroid hormones demonstrated binding of (/sup 125/I)T4 to transthyretin, thyroid hormone-binding globulin, and albumin and of (/sup 125/I)T3 primarily to thyroid hormone-binding globulin. In all abnormal sera, polyacrylamide gel electrophoresis demonstrated strikingly higher binding of T3 to immunoglobulin (Ig). Eleven of 16 abnormal sera had minimal to moderate binding of T4 to Ig. The percent free T4 was lower only in dogs whose sera demonstrated markedly increased binding of T4 to Ig. All abnormal sera tested had positive antithyroglobulin antibodies, consistent with the diagnosis of autoimmune lymphocytic thyroiditis. As in humans, antibodies to thyroid hormones in dogs are more common in the presence of Hashimoto's thyroiditis and should be considered when elevated serum thyroid hormone concentrations are observed in the absence of clinical thyrotoxicosis. When an antibody to only one thyroid hormone is present, a marked discrepancy in the serum concentrations of T3 and T4 will be observed.

Sex-hormone binding globulin (SHBG) levels during pregnancy as predictors for pre-eclampsia and fetal growth restriction

OpenAIRE

Valdés R, Enrique; Lattes A, Karina; Muñoz S, Hernán; Ángel Cumsille, Miguel

2012-01-01

Background: Sex-Hormone Binding Globulin (SHBG) may be associated to Pre-eclampsia (PE) and Fetal Growth Restriction (RCIU). Aim: To determine if maternal serum SHBG concentrations during the first and second trimesters are predictive biomarkers of Pre-eclampsia and RCIU. Patients and Methods: Prospective cohort study carried out in the Fetal Medicine Unit, Universidad de Chile Clinical Hospital between January, 2005 and December, 2006. Blood samples were obtained from unselectedpregnant wome...

Genetics Home Reference: lysosomal acid lipase deficiency

Science.gov (United States)

... lipase deficiency develop multi-organ failure and severe malnutrition and generally do not survive past 1 year. In the later-onset form of lysosomal acid lipase deficiency , signs and symptoms vary and usually begin in mid-childhood, although they can appear anytime up to late ...

Characterization of mini-protein S, a recombinant variant of protein S that lacks the sex hormone binding globulin-like domain

NARCIS (Netherlands)

van Wijnen, M.; Stam, J. G.; Chang, G. T.; Meijers, J. C.; Reitsma, P. H.; Bertina, R. M.; Bouma, B. N.

1998-01-01

Protein S is a vitamin K-dependent glycoprotein involved in the regulation of the anticoagulant activity of activated protein C (APC). Also, an anticoagulant role for protein S, independent of APC, has been described. Protein S has a unique C-terminal sex hormone binding globulin (SHBG)-like domain

Lipase from a Brazilian strain of Penicillium citrinum.

Science.gov (United States)

Pimentel, M C; Krieger, N; Coelho, L C; Fontana, J O; Melo, E H; Ledingham, W M; Lima Filho, J L

1994-10-01

A lipases (glycerol ester hydrolases E. C. 3.1.1.3) from a brazilian strain of Penicillium citrinum has been investigated. When the microorganism was cultured in the simple medium (1.0% olive oil and 0.5% yeast extract), using olive oil in as carbon source in the inocula, the enzyme extracted showed maximum activity (409 IU/mL). In addition, decrease of yeast extract concentration also reduces the lipase activity. Nevertheless, when yeast extract was replaced by ammonium sulfate, no activity was detected. Purification by precipitation with ammonium sulfate showed best activity in the 40-60% fraction. The optimum temperature for enzyme activity was found in the range of 34-37 degrees C. However, after 30 min at 60 degrees C, the enzyme was completely inactivated. The enzyme showed optimum at pH 8.0. The dried concentrated fraction (after dialysis and lyophilization) maintained its lipase activity at room temperature (28 degrees C) for 8 mo. This result in lipase stability suggests an application of lipases from P. citrinum in detergents and other products that require a high stability at room temperature.

Dependency of water concentration on ethanolysis of trioleoylglycerol by lipases

DEFF Research Database (Denmark)

Piyatheerawong, W.; Iwasaki, Y; Xu, Xuebing

2004-01-01

tested (Rhizomucor miehei lipase, Burkholderia cepacia lipase and Thermomyces lanuginosus lipase) required larger amounts of free water (ca. 7-9 wt.%) for their best performance and exhibited no ethanolysis reaction at low free water concentrations. The CALB's anomalous behavior was also observed...

[Role of the Periaqueductal Gray Matter of the Midbrain in Regulation of Somatic Pain Sensitivity During Stress: Participation of Corticotropin-Releasing Factor and Glucocorticoid Hormones].

Science.gov (United States)

Yarushkina, N I; Filaretova, L P

2015-01-01

Periaqueductal gray matter of the midbrain (PAGM) plays a crucial role in the regulation of pain sensitivity under stress, involving in the stress-induced analgesia. A key hormonal system of adaptation under stress is the hypothalamic-pituitary-adrenocortical (HPA) axis. HPA axis's hormones, corticotropin-releasing factor (CRF) and glucocorticoids, are involved in stress-induced analgesia. Exogenous hormones of the HPA axis, similarly to the hormones produced under stress, may cause an analgesic effect. CRF-induced analgesia may be provided by glucocorticoid hormones. CRF and glucocorticoids-induced effects on somatic pain sensitivity may be mediated by PAGM. The aim of the review was to analyze the data of literature on the role of PAGM in the regulation of somatic pain sensitivity under stress and in providing of CRF and glucocorticoid-induced analgesia.

Bioremediation of cooking oil waste using lipases from wastes.

Directory of Open Access Journals (Sweden)

Clarissa Hamaio Okino-Delgado

Full Text Available Cooking oil waste leads to well-known environmental impacts and its bioremediation by lipase-based enzymatic activity can minimize the high cytotoxic potential. In addition, they are among the biocatalysts most commercialized worldwide due to the versatility of reactions and substrates. However, although lipases are able to process cooking oil wastes, the products generated from this process do not necessarily become less toxic. Thus, the aim of the current study is to analyze the bioremediation of lipase-catalyzed cooking oil wastes, as well as their effect on the cytotoxicity of both the oil and its waste before and after enzymatic treatment. Thus, assessed the post-frying modification in soybean oil and in its waste, which was caused by hydrolysis reaction catalyzed by commercial and home-made lipases. The presence of lipases in the extracts obtained from orange wastes was identified by zymography. The profile of the fatty acid esters formed after these reactions was detected and quantified through gas chromatography and fatty acids profile compared through multivariate statistical analyses. Finally, the soybean oil and its waste, with and without enzymatic treatment, were assessed for toxicity in cytotoxicity assays conducted in vitro using fibroblast cell culture. The soybean oil wastes treated with core and frit lipases through transesterification reaction were less toxic than the untreated oils, thus confirming that cooking oil wastes can be bioremediated using orange lipases.

Screening of thermophilic neutral lipase-producing Pseudomonas ...

African Journals Online (AJOL)

From oil-contaminated soil, three lipase-producing microorganisms were selected as good lipase producers using rhodamine B-olive oil plate agar and they were identified as from Pseudomonas, Burkholderia and Klebsiella genera by morphology, biochemical characterization and 16S rRNA gene sequencing. Among the ...

Sex hormone-binding globulin as a marker for the thrombotic risk of hormonal contraceptives.

NARCIS (Netherlands)

Raps, M.; Helmerhorst, F.; Fleischer, K.; Thomassen, S.; Rosendaal, F.; Rosing, J.; Ballieux, B.; Vliet, H. van

2012-01-01

BACKGROUND: It takes many years to obtain reliable values for the risk of venous thrombosis of hormonal contraceptive users from clinical data. Measurement of activated protein C (APC) resistance via thrombin generation is a validated test for determining the thrombogenicity of hormonal

Sensitivity of anterior pituitary hormones to graded levels of psychological stress.

Science.gov (United States)

Armario, A; Lopez-Calderón, A; Jolin, T; Castellanos, J M

1986-08-04

The effect of graded levels of stressor intensity on anterior pituitary hormones was studied in adult male rats. Corticosterone, considered as a reflection of ACTH release, and prolactin responses showed a good correlation with the intensity of the stressors. On the contrary, neither LH, GH nor TSH release showed a parallelism with the intensity of the stressors in spite of the fact that they clearly responded to all the stimuli. It appears that the hormones of the anterior pituitary might be divided into two groups: those whose response is sensitive to the levels of emotional arousal elicited by stress, and those displaying a clear but stereotyped response during stress. However, other alternative explanations might exist to justify the present results. The neural mechanisms underlying the two types of response are at present unknown. These data indicate that only the pituitary-adrenal axis and prolactin have some potential utilities as quantitative indices of emotional arousal elicited by currently applied stressors in the rat.

Frozen Microemulsions for MAPLE Immobilization of Lipase

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Valeria Califano

2017-12-01

Full Text Available Candida rugosa lipase (CRL was deposited by matrix assisted pulsed laser evaporation (MAPLE in order to immobilize the enzyme with a preserved native conformation, which ensures its catalytic functionality. For this purpose, the composition of the MAPLE target was optimized by adding the oil phase pentane to a water solution of the amino acid 3-(3,4-dihydroxyphenyl-2-methyl-l-alanine (m-DOPA, giving a target formed by a frozen water-lipase-pentane microemulsion. Fourier transform infrared (FTIR spectroscopy and atomic force microscopy (AFM were used to investigate the structure of MAPLE deposited lipase films. FTIR deconvolution of amide I band indicated a reduction of unfolding and aggregation, i.e., a better preserved lipase secondary structure in the sample deposited from the frozen microemulsion target. AFM images highlighted the absence of big aggregates on the surface of the sample. The functionality of the immobilized enzyme to promote transesterification was determined by thin layer chromatography, resulting in a modified specificity.

Microbial lipases: Production, properties and biotechnological applications

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Josana Maria Messias

2011-09-01

Full Text Available Lipases belong to the group of hydrolases that catalyze the hydrolysis of triacylglycerol lipids to free fatty acids and glycerol. They have significant potential biotechnological applications in catalyzing organic synthesis reactions in non-aqueous solvents using simplified procedures resulting in conversions of high yields. Lipase production has conventionally been performed by submerged fermentation; however, solid-state fermentation processes have been prominent when residues are used as substrates because they serve as low-cost nutrient sources. Microbial lipases can be used as additives in foods to modify and enhance organoleptic properties, as well as in detergents to hydrolyse fats in the treatment of oily effluents, and also have value for pharmaceutical, cosmetic, agrochemical, and oil chemical industries. More recently, they are used in transesterification reactions to convert plant seed oils into biodiesel. The objective of this work was to review the published literature on the production, properties and applications of microbial lipases, and its biotechnological role in producing biodiesel.

Structure of product-bound SMG1 lipase: active site gating implications.

Science.gov (United States)

Guo, Shaohua; Xu, Jinxin; Pavlidis, Ioannis V; Lan, Dongming; Bornscheuer, Uwe T; Liu, Jinsong; Wang, Yonghua

2015-12-01

Monoacylglycerol and diacylglycerol lipases are industrially interesting enzymes, due to the health benefits that arise from the consumption of diglycerides compared to the traditional triglyceride oils. Most lipases possess an α-helix (lid) directly over the catalytic pocket which regulates the activity of the enzyme. Generally, lipases exist in active and inactive conformations, depending on the positioning of this lid subdomain. However, lipase SMG1, a monoacylglycerol and diacylglycerol specific lipase, has an atypical activation mechanism. In the present study we were able to prove by crystallography, in silico analysis and activity tests that only two positions, residues 102 and 278, are responsible for a gating mechanism that regulates the active and inactive states of the lipase, and that no significant structural changes take place during activation except for oxyanion hole formation. The elucidation of the gating effect provided data enabling the rational design of improved lipases with 6-fold increase in the hydrolytic activity toward diacylglycerols, just by providing additional substrate stabilization with a single mutation (F278N or F278T). Due to the conservation of F278 among the monoacylglycerol and diacylglycerol lipases in the Rhizomucor miehei lipase-like family, the gating mechanism described herein might represent a general mechanism applicable to other monoacylglycerol and diacylglycerol lipases as well. Database: Structural data are available in the Protein Data Bank under the accession numbers 4ZRE (F278D mutant) and 4ZRD (F278N mutant). © 2015 FEBS.

Karakterisasi ekstrak kasar lipase Rhizopus stolonifer UICC 137

Directory of Open Access Journals (Sweden)

Sri Sumiarsih

2001-12-01

Full Text Available There is an increasing commercial interest in enzymatic production of biologically active component, because there are a number of well-known advantages compared to chemical synthesis. One of the most valuable synthetic features of enzyme is their ability to discriminate between enantiomers of racemic substrates. Lipase have become of great interest to the chemical industries wing their usefulness in both hydrolytic and synthesis reactions. The aim of this work was to study the production of lipase by Rhizopus stolonifer UICC 137, and determine the crude lipase preparation characteristics. The lipolytic activity was determined by titrimetric method toward oil-arabic gum emultion as a substrate. The strain produced lipase at appreciable lipolytic when cultivated for 72 hours in medium containing 3% glucose and 1% olive oil. Our data suggest that the strain produced lipase since the exponential phase of its growth. Lipase with optimum lipolytic activity was obtained at late stationary phase. The optimum condition for lipolytic activity measurement were pH of 7.5 and temperature 37oC, the crude enzyme had a specific activity 20.2 unit/ mg protein, the Vmax was 15.1 mol/ min and KM was 12.5 mg/ ml. The crude enzyme retained 79.9%, 68.0% and 52.6% of its lipolytic activity, when incubated for 90 minutes at temperature of 40, 50, and 60oC respectively.

The specificity of Several Kinds Lipases on n-3 Polyunsaturated Fatty Acids

Directory of Open Access Journals (Sweden)

Jenny Elisabeth, T Yuliani, P M Tambunan, J M Purba

2001-04-01

Full Text Available Several lipases from microbial and plant, i.e Rhizomucor miehei, Pseudomonas sp., Candida antartica, rice bran, and Carica papaya latex (CPL were examined for synthesis of omega-3 (n-3 PUFA-rich glyceride by hydrolysis and acidolysis reaction. Tuna oil was used in hydrolysis reaction, whereas tuna and palm oils were used as source of triglyceride (TAG molecules and n-3 PUFA concentrate from tuna oil as source of EPA and DHA in acidolysis reaction.For hydrolysis reaction, the rice bran and CPL lipases showed the lowest hydrolytic activity of the tuna oil, whereas the R. miehei lipase showed the highest hydrolytic activity but was unable to hydrolyze EPA and DHA. On the contrary, the C. antartica and Pseudomonas sp. lipases acted stronger on hydrolysis of DHA ester bond than EPA.For acidolysis reaction, all the lipases showed ability to incorporate n-3 PUFA into tuna and palm oils. C. antartica lipase had the maximum DHA incorporation into tuna and palm oils, rice bran lipase had relatively similar ability with R. miehei lipase, and the CPL lipase had the lowest ability. This study proved that rice bran and CPL lipases also had transesterification activity and showed the feasibility of the rice bran lipase to be a biocatalyst for n-3 PUFA-rich glyceride production. Increasing the substrate ratio, of n-3 PUFA concentrate and tuna or palm oil, could increase the EPA and DHA incorporation. The R. miehei, rice bran, and CPL lipases unabled to incorporate DHA into DHA-containing glyceride molecule, whereas C. antartica lipase had the capability in high ratio of n-3 PUFA concentrate to oil. Therefore, the lipases were easier to incorporate n-3 PUFA into palm oil than tuna oil, since the TAG molecules of palm oil was not as complex as tuna oil. It could be suggested that the lipases did not only have acyl chain and positional specificity, but also the whole glyceride structure specificity.

Interaction of thyroid hormone and hemoglobin: nature of the interaction and effect of hemoglobin on thyroid hormone radioimmunoassay

International Nuclear Information System (INIS)

Davis, P.J.; Yoshida, K.; Schoenl, M.

1980-01-01

Gel filtration of human erythrocyte (RBC) lysate incubated with labeled thyroxine (Tu) or triiodothyronine (Tt) revealed co-elution of a major iodothyronine-binding fraction (R-2) and hemoglobin. Solutions of purified human hemoglobin and Tt also showed co-elution of hormone and hemoglobin. Because hematin and protoporphyrin were shown to bind labeled Tt, the oxygen-binding site on hemoglobin was excluded as the site of iodothyronine-hemoglobin interaction. Analysis of hormone binding by heme and globin moieties showed Tt binding to be limited to the heme fraction. Addition of excess unlabeled Tt to hemoglobin or heme incubated with labeled Tt indicated 75% to 90% of hormone binding was poorly dissociable. These observations suggested that the presence of hemoglobin in RBC lysate or in serum could influence the measurement of Tu and Tt by specific radioimmunoassay (RIA). Subsequent studies of the addition to serum of human hemoglobin revealed a significant reduction in Tt and Tu detectable by RIA in the presence of this protein. The effect was influenced by the concentration of hemoglobin and by duration and temperature of incubations of hemoglobin and serum prior to RIA

Sex hormone binding globulin - an important biomarker for predicting PCOS risk: A systematic review and meta-analysis.

Science.gov (United States)

Deswal, Ritu; Yadav, Arun; Dang, Amita Suneja

2018-02-01

Sex hormone-binding globulin (SHBG) is a glycoprotein which regulates bioavailability of sex steroid hormones. Interest in SHBG has escalated in recent years because of its inverse association with polycystic ovary syndrome (PCOS), obesity, insulin resistance, metabolic syndrome, and diabetes type II. This meta-analysis was performed to examine the associations of SHBG with PCOS and to correlate serum SHBG levels with various PCOS associated endocrine and metabolic dysregulation as well as to determine the effects of various therapeutic agents on serum SHBG levels in PCOS patients in order to assess the true accuracy of SHBG in the prediction of PCOS. A literature search was performed using Pub-Med, Science direct, google scholar, EMBASE, and Cochrane library. A total of 675 relevant records were identified, of which 62 articles were included. Meta-analysis using a random-effects model was performed using STATA version 13 to calculate standardized mean difference (SMD) with 95% confidence intervals (95 % CIs). SHBG levels in controls were significantly higher than that of PCOS patients (SMD= -0.83, 95%CI = -1.01, -0.64), with significant heterogeneity across studies (I 2 = 93.9% and p=0.000). Our results suggest that the lower serum SHBG levels are associated with the risk of PCOS. SHBG may also play an important role in various metabolic disturbances in PCOS patients. Therapeutic interventions improved SHBG levels in PCOS women which further reduced PCOS associated complications. Therefore, SHBG levels may prove to be a useful biomarker for the diagnosis and treatment of PCOS. Systematic review registration: PROSPERO CRD42017057972 Abbreviations: PCOS: polycystic ovary syndrome; SHBG: sex hormone-binding globulin.

Mutation induced enhanced biosynthesis of lipase | Bapiraju ...

African Journals Online (AJOL)

The purpose of the present investigation is to enhance production of biomedically important enzyme lipase by subjecting the indigenous lipase producing strain Rhizopus sp. BTS-24 to improvement by natural selection and random mutagenesis (UV and N-methyl-N'-nitro-N-nitroso guanidine, NTG). The isolation of mutants ...

Lipase and esterase: to what extent can this classification be applied accurately?

Directory of Open Access Journals (Sweden)

Danielle Branta Lopes

2011-09-01

Full Text Available Enzyme technology is an ever-growing field of knowledge and, in recent years, this technology has raised renewed interest, due to the search for new paradigms in several productive processes. Lipases, esterases and cutinases are enzymes used in a wide range of processes involving synthesis and hydrolysis reactions. The objective of this work was to investigate and compare the specific lipase and esterase activities of five enzymes - four already classified as lipases and one classified as cutinase - in the presence of natural and synthetic substrates. All tested enzymes presented both esterase and lipase specific activities. The highest specific esterase activity was observed for Aspergillus 1068 lipase in natural substrate and for F. oxysporum cutinase in synthetic substrate, while the highest specific lipase activity was observed for Geotrichum sp. lipase in natural substrate and for F. oxysporum cutinase in synthetic substrate. These results display some interface-independent lipolytic activity for all lipases tested. This is in accordance with the rationale that a new and broader definition of lipases may be necessary.

Lipase inactivation in wheat germ by gamma irradiation

International Nuclear Information System (INIS)

Jha, Pankaj Kumar; Kudachikar, V.B.; Kumar, Sourav

2013-01-01

An attempt was made to improve the shelf life of wheat germ by optimizing processing conditions involving γ-irradiation. Studies were carried out to investigate the effect of γ-irradiation (0–30 kGy doses) on the chemical composition of wheat germ with respect to variation in moisture, total ash, crude fat, free fatty acid, protein and lipase activity. The results demonstrate that shelf stability of wheat germ was achieved by inactivation of lipase at doses of γ-irradiation greater than 12 kGy. - Highlights: Ø γ-irradiation was found to inactivate Lipase present in Wheat Germ. Ø The treatment did not result in significant changes in Total Ash, Moisture and Protein Content of Wheat Germ. Ø The irradiation at 30 kGy resulted in 31.2 % inactivation of Lipase in Wheat Germ

Production of Cold Active Lipase from Bacillus sp.

OpenAIRE

Yasemin, Sara; Arabacı, Nihan; Korkmaz Güvenmez, Hatice

2018-01-01

A cold active lipase producing Bacillus sp. strains were isolated from sewage of oil. Bacillus sp. strain SY-7 was determined as the best lipase producing isolate. The highest enzyme production was found at 20°C and pH 8.0 on tributyrin media. Analyses of molecular mass of the partial purified lipase was carried out by SDS-PAGE which revealed a single band as 110.5 kDa. The enzyme activity and stability were determined by spectrophotometric and titrimetric methods. The enzyme was active betwe...

Zymography Detection of a Bacterial Extracellular Thermoalkaline Esterase/Lipase Activity.

Science.gov (United States)

Tapizquent, María; Fernández, Marleny; Barreto, Georgina; Hernández, Zully; Contreras, Lellys M; Kurz, Liliana; Wilkesman, Jeff

2017-01-01

Lipases are esterases that occur widely in nature, yet those with commercial relevance are exclusively from microbial origin. Glycerol and long-chain fatty acids are the products after hydrolysis of esters bonds in saponifiable lipids catalyzed by lipases. In this work, we describe lipase/esterase activity contained in cell-free fractions from thermophilic bacteria, cultured in medium containing olive oil. Analysis of the cell-free fractions by electrotransference zymography, using tributyrin as substrate, revealed bands corresponding to lipase activity. The method is simple, fast, and inexpensive.

Purification and characterization of a new cold active lipase, EnL A ...

African Journals Online (AJOL)

Search of lipase engineering data base (LED) revealed that this protein belongs to a newly introduced super family of Candida antarctica lipase A like and to the homologous family of Aspergillus lipase like. Key words: Cold active lipase, Emericella nidulans, hydrophobic interaction chromatography, Candida antarctica ...

Realm of Thermoalkaline Lipases in Bioprocess Commodities

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Ahmad Firdaus B. Lajis

2018-01-01

Full Text Available For decades, microbial lipases are notably used as biocatalysts and efficiently catalyze various processes in many important industries. Biocatalysts are less corrosive to industrial equipment and due to their substrate specificity and regioselectivity they produced less harmful waste which promotes environmental sustainability. At present, thermostable and alkaline tolerant lipases have gained enormous interest as biocatalyst due to their stability and robustness under high temperature and alkaline environment operation. Several characteristics of the thermostable and alkaline tolerant lipases are discussed. Their molecular weight and resistance towards a range of temperature, pH, metal, and surfactants are compared. Their industrial applications in biodiesel, biodetergents, biodegreasing, and other types of bioconversions are also described. This review also discusses the advance of fermentation process for thermostable and alkaline tolerant lipases production focusing on the process development in microorganism selection and strain improvement, culture medium optimization via several optimization techniques (i.e., one-factor-at-a-time, surface response methodology, and artificial neural network, and other fermentation parameters (i.e., inoculums size, temperature, pH, agitation rate, dissolved oxygen tension (DOT, and aeration rate. Two common fermentation techniques for thermostable and alkaline tolerant lipases production which are solid-state and submerged fermentation methods are compared and discussed. Recent optimization approaches using evolutionary algorithms (i.e., Genetic Algorithm, Differential Evolution, and Particle Swarm Optimization are also highlighted in this article.

Realm of Thermoalkaline Lipases in Bioprocess Commodities.

Science.gov (United States)

Lajis, Ahmad Firdaus B

2018-01-01

For decades, microbial lipases are notably used as biocatalysts and efficiently catalyze various processes in many important industries. Biocatalysts are less corrosive to industrial equipment and due to their substrate specificity and regioselectivity they produced less harmful waste which promotes environmental sustainability. At present, thermostable and alkaline tolerant lipases have gained enormous interest as biocatalyst due to their stability and robustness under high temperature and alkaline environment operation. Several characteristics of the thermostable and alkaline tolerant lipases are discussed. Their molecular weight and resistance towards a range of temperature, pH, metal, and surfactants are compared. Their industrial applications in biodiesel, biodetergents, biodegreasing, and other types of bioconversions are also described. This review also discusses the advance of fermentation process for thermostable and alkaline tolerant lipases production focusing on the process development in microorganism selection and strain improvement, culture medium optimization via several optimization techniques (i.e., one-factor-at-a-time, surface response methodology, and artificial neural network), and other fermentation parameters (i.e., inoculums size, temperature, pH, agitation rate, dissolved oxygen tension (DOT), and aeration rate). Two common fermentation techniques for thermostable and alkaline tolerant lipases production which are solid-state and submerged fermentation methods are compared and discussed. Recent optimization approaches using evolutionary algorithms (i.e., Genetic Algorithm, Differential Evolution, and Particle Swarm Optimization) are also highlighted in this article.

Relationship between laminin binding capacity and laminin expression on tumor cells sensitive or resistant to natural cell-mediated cytotoxicity

International Nuclear Information System (INIS)

Laybourn, K.A.; Varani, J.; Fligiel, S.E.G.; Hiserodt, J.C.

1986-01-01

Previous studies have identified the presence of laminin binding sites on murine NK and NC sensitive tumor cells by 125 I-laminin binding and laminin induced cell-cell aggregation. The finding that the addition of exogenous laminin inhibits NK/NC binding to sensitive tumor cells suggests laminin binding sites may serve as target antigens for NK cells. The present study extends earlier reports by analyzing a large panel of tumor cells for laminin binding capacity, laminin expression and sensitivity to NK/NC killing. The data indicate that all tumor cells which bind to NK/NC cells (8 lines tested) express laminin binding sites. All of these tumor cells were capable of competing for NK lysis of YAC-1 cells in cold target competition assays, and all bound enriched NK cells in direct single cell binding assays. In contrast, tumor cells expressing high levels of surface laminin (B16 melanomas, C57B1/6 fibrosarcomas, and RAS transfected 3T3 fibroblasts) but low levels of laminin binding capacity did not bind NK/NC cells and were resistant to lysis. These data support the hypothesis that expression of laminin/laminin binding sites may contribute to tumor cell sensitivity to NK/NC binding and/or killing

Liver lipase and high-density lipoprotein. Lipoprotein changes after incubation of human serum with rat liver lipase.

Science.gov (United States)

Groot, P H; Scheek, L M; Jansen, H

1983-05-16

Human sera were incubated with rat liver lipase after inactivation of lecithin:cholesterol acyltransferase, and the changes in serum lipoprotein composition were measured. In the presence of liver lipase serum triacylglycerol and phosphatidylcholine were hydrolyzed. The main changes in the concentrations of these lipids were found in the high-density lipoprotein fraction. Subfractionation of high-density lipoprotein by rate-zonal ultracentrifugation showed a prominent decrease in all constituents of high-density lipoprotein2, a smaller decrease in the 'light' high-density lipoprotein3 and an increase in the 'heavy' high-density lipoprotein3. These data support a concept in which liver lipase is involved in high-density lipoprotein2 phospholipid and triacylglycerol catabolism and suggest that as a result of this action high-density lipoprotein2 is converted into high-density lipoprotein3.

Radioimmunoassay and the hormones of thyroid function

International Nuclear Information System (INIS)

Stahl, R.J.

1975-01-01

Radioimmunoassay (RIA) has provided the tools for wide-reaching investigations that have changed and continue to change many important concepts of thyroid physiology and pathophysiology. The RIA for human thyrotropin (TSH) was developed in 1965; development of the RIA for triiodothyronine (T 3 ), thyroxine(T 4 ), thyroxine-binding globulin (TBG), and recently, thyrotropin-releasing hormone (TRH) and thyroglobulin (Tg) followed. The capacity to measure nanogram and picogram concentrations with relative ease and speed has permitted the demonstration of dynamic relationships of the intrathyroidal and circulating thyroid hormones to each other and to the pituitary and hypothalamic regulating hormones. Evidence for the presence of cross-influences between TRH and other hypothalamic regulating hormones on the secretion of pituitary hormones has accumulated. The impact of the new information on clinical practice is now becoming evident. There is new appreciation of the value of assaying serum T 3 and TSH concentrations in the clinical management of patients with disturbed function of the thyroid, pituitary, or hypothalamus. The necessary components for RIA performance can be purchased separately or in kit form from commercial sources. With appropriate quality-control procedures, precise, sensitive, and reliable data can be generated. Awareness of the specific technical problems relating to the RIA of these hormones is absolutely necessary to assure reliable results. The availability of kits or their components permits the performance of these studies in the community hospital and in reliable commercial-service laboratories. (U.S.)

21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Esterase-lipase derived from Mucor miehei. 173.140... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme derived from Mucor miehei var. Cooney et Emerson by...

Beneficial effects of adding lipase enzyme to broiler diet

International Nuclear Information System (INIS)

Elbarkouky, E.M.A.

2005-01-01

A total number of 300 Ross broiler chicks were obtained from commercial hatchery at one day of age. The chicks were divided into three groups (50 males and 50 females in each). The first and second groups were supplemented with 3000 and 2000 lU/kg diet of lipase enzyme, respectively, while the third group served as control and fed on basal diet. Birds fed on diets that supplemented with lipase enzyme showed significant increase in body weight and dry matter intake, as well as fats and protein content dry matters. The serum lipase activity showed significant increase in treated groups compared to the control. Non-significant changes were determined in serum total lipids, T3, T4 and ash content. Birds supplemented with lipase showed significant decrease in cholesterol concentration. It could be concluded that birds fed diets containing 2000 or 3000 lU/kg diet of lipase enzyme exhibited improvement in broiler performance

Anti- and pro-lipase activity of selected medicinal, herbal and aquatic plants, and structure elucidation of an anti-lipase compound.

Science.gov (United States)

Ado, Muhammad Abubakar; Abas, Faridah; Mohammed, Abdulkarim Sabo; Ghazali, Hasanah M

2013-11-26

Plants that help in slowing down the digestion of triacylglycerols (TAGs) in the pancreas and small intestine of humans play an important role in the reduction of obesity. On the other hand, there may be plants or plant parts that stimulate intestinal lipolytic activity, thus contributing to greater TAG assimilation. The aim of this study was to evaluate the aqueous methanolic extracts of ninety eight (98) medicinal, herbal and aquatic plant materials from Malaysia for their effect on porcine pancreatic lipase (PPL) activity and to identify the structure of an anti-lipase compound from one of the sources. The degree of inhibition was also quantified as relative to orlistat activity against PPL (orlistat equivalents). Results revealed that while 19.4% of the extracts were found to have anti-lipase activity ≥80%, 12% were actually found to promote PPL activity. Twenty two percent (22.4%) exhibited moderate inhibition (41%-80%) and 2% were neutral toward PPL activity. The ripe fruit of Averrhoa carambola and the leaves of Archidendron jiringa (Jack) I.C Nielsen L. (jering), Cynometra cauliflora (nam-nam) and Aleurites moluccana (L.) Willd (candle nut/buah keras) had the highest (100%) anti-lipase activity and are equivalent to 0.11 µg orlistat/mL. Plants that stimulated lipase activity included Pimpinella anisum L. (aniseed/jintan manis), activating the enzyme by 186.5%. Kaempferol 3-O-rhamnoside was isolated from the ethyl acetate fraction of C. cauliflora leaves and found to be an active lipase inhibitor. The structure was elucidated using 1H-NMR, 13C-NMR and 2D-NMR analyses.

Michelangelo, the Sistine Chapel and the “secret” of cancer cachexia

African Journals Online (AJOL)

irrespective of the relative contribution of anorexia and metabolic changes. Cancer anorexia ... component of the homoeostatic circuit that regulates energy balance by mediating .... hormone-sensitive lipase (HSL), a rate-limiting enzyme of the.

ENZYMATIC BIODIESEL SYNTHESIS FROM ACID OIL USING A LIPASE MIXTURE

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Kelly C. N. R. Pedro

Full Text Available The conventional biodiesel production process has some disadvantages. It is necessary to use refined vegetable oils with low free fatty acids (FFAs content. An alternative route is to use low-cost acid oils in an enzymatic process. The use of lipases allows simultaneous esterification of FFAs and transesterification of triglycerides present in raw material forming alkyl esters. The aim of this work was to study the production of biodiesel using soybean oils with different acid contents (Acid Value of 8.5, 50, 90 and ethanol catalyzed by commercial immobilized lipases (Novozym 435, Lipozyme RM IM and Lipozyme TL IM. A significant decrease of acid value was observed mainly with Novozym 435 and Lipozyme RM IM. The use of a mixture of two immobilized lipases was also investigated to decrease catalyst cost and increase the amount of ester produced. The three commercial immobilized lipases were mixed in a dual system and tested for biodiesel synthesis from acid oil (AV of 8.5, 50 and 90. A positive synergistic effect occurred mainly for Lipozyme TL IM (1,3-specific lipase and Novozym 435 (non-specific lipase blend. The ester content doubled when this lipase mixture was used in ethanolysis of acid oil with AV of 90.

Prognostic Factors for Hormone Sensitive Metastatic Prostate Cancer: Impact of Disease Volume

Science.gov (United States)

Alhanafy, Alshimaa Mahmoud; Zanaty, Fouad; Ibrahem, Reda; Omar, Suzan

2018-04-27

Background and Aim: The optimal management of metastatic hormone-sensitive prostate cancer has been controversial in recent years with introduction of upfront chemohormonal treatment based on results of several Western studies. This changing landscape has renewed interest in the concept “disease volume”, the focus of the present study is the Egyptian patients. Methods: Patients with hormone sensitive metastatic prostate cancer presenting at Menoufia University Hospital, Egypt, during the period from June 2013 to May 2016, were enrolled. All received hormonal treatment. Radiologic images were evaluated and patients were stratified according to their disease volume into high or low, other clinical and pathological data that could affect survival also being collected and analyzed. Results: A total of 128 patients were included, with a median age of 70 years (53.9% ≥70). About 46% had co-morbidities, 62% having high volume disease. During the median follow up period of 28 months about half of the patients progressed and one third received chemotherapy. On univariate analysis, disease volume, performance status (PS), prostate specific antigen level (PSA) and presence of pain at presentation were identified as factors influencing overall survival. Multivariate analysis revealed the independent predictor factors for survival to be PS, PSA and disease volume. The median overall survival with 27 months was high volume versus 49 with low volume disease (hazard ratio 2.1; 95% CI 1.2 - 4.4; P=0.02). Median progression free survival was 19 months in the high volume, as compared with 48 months in the low volume disease patients (hazard ratio, 2.44; 95% CI, 1.42 – 7.4; P=0.009). Conclusions: Disease volume is a reliable predictor of survival which should be incorporated with other important factors as; patient performance status and comorbidities in treatment decision-making. Creative Commons Attribution License

Biotechnological applications of halophilic lipases and thioesterases.

Science.gov (United States)

Schreck, Steven D; Grunden, Amy M

2014-02-01

Lipases and esterases are enzymes which hydrolyze ester bonds between a fatty acid moiety and an esterified conjugate, such as a glycerol or phosphate. These enzymes have a wide spectrum of use in industrial applications where their high activity, broad substrate specificity, and stability under harsh conditions have made them integral in biofuel production, textile processing, waste treatment, and as detergent additives. To date, these industrial applications have mainly leveraged enzymes from mesophilic and thermophilic organisms. However, increasingly, attention has turned to halophilic enzymes as catalysts in environments where high salt stability is desired. This review provides a brief overview of lipases and esterases and examines specific structural motifs and evolutionary adaptations of halophilic lipases. Finally, we examine the state of research involving these enzymes and provide an in-depth look at an exciting algal-based biofuel production system. This system uses a recombinant halophilic lipase to increase oil production efficiency by cleaving algal fatty acids from the acyl carrier protein, which eliminates feedback inhibition of fatty acid synthesis.

Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

OpenAIRE

Dali, Seniwati; Patong, A. B. D. Rauf; Jalaluddin, M. Noor; Pirman; Hamzah, Baharuddin

2011-01-01

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum ...

Development of a method for comprehensive and quantitative analysis of plant hormones by highly sensitive nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry

International Nuclear Information System (INIS)

Izumi, Yoshihiro; Okazawa, Atsushi; Bamba, Takeshi; Kobayashi, Akio; Fukusaki, Eiichiro

2009-01-01

In recent plant hormone research, there is an increased demand for a highly sensitive and comprehensive analytical approach to elucidate the hormonal signaling networks, functions, and dynamics. We have demonstrated the high sensitivity of a comprehensive and quantitative analytical method developed with nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS/MS) under multiple-reaction monitoring (MRM) in plant hormone profiling. Unlabeled and deuterium-labeled isotopomers of four classes of plant hormones and their derivatives, auxins, cytokinins (CK), abscisic acid (ABA), and gibberellins (GA), were analyzed by this method. The optimized nanoflow-LC-ESI-IT-MS/MS method showed ca. 5-10-fold greater sensitivity than capillary-LC-ESI-IT-MS/MS, and the detection limits (S/N = 3) of several plant hormones were in the sub-fmol range. The results showed excellent linearity (R 2 values of 0.9937-1.0000) and reproducibility of elution times (relative standard deviations, RSDs, <1.1%) and peak areas (RSDs, <10.7%) for all target compounds. Further, sample purification using Oasis HLB and Oasis MCX cartridges significantly decreased the ion-suppressing effects of biological matrix as compared to the purification using only Oasis HLB cartridge. The optimized nanoflow-LC-ESI-IT-MS/MS method was successfully used to analyze endogenous plant hormones in Arabidopsis and tobacco samples. The samples used in this analysis were extracted from only 17 tobacco dry seeds (1 mg DW), indicating that the efficiency of analysis of endogenous plant hormones strongly depends on the detection sensitivity of the method. Our analytical approach will be useful for in-depth studies on complex plant hormonal metabolism.

Development of a method for comprehensive and quantitative analysis of plant hormones by highly sensitive nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Izumi, Yoshihiro; Okazawa, Atsushi; Bamba, Takeshi; Kobayashi, Akio [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Fukusaki, Eiichiro, E-mail: fukusaki@bio.eng.osaka-u.ac.jp [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2009-08-26

In recent plant hormone research, there is an increased demand for a highly sensitive and comprehensive analytical approach to elucidate the hormonal signaling networks, functions, and dynamics. We have demonstrated the high sensitivity of a comprehensive and quantitative analytical method developed with nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS/MS) under multiple-reaction monitoring (MRM) in plant hormone profiling. Unlabeled and deuterium-labeled isotopomers of four classes of plant hormones and their derivatives, auxins, cytokinins (CK), abscisic acid (ABA), and gibberellins (GA), were analyzed by this method. The optimized nanoflow-LC-ESI-IT-MS/MS method showed ca. 5-10-fold greater sensitivity than capillary-LC-ESI-IT-MS/MS, and the detection limits (S/N = 3) of several plant hormones were in the sub-fmol range. The results showed excellent linearity (R{sup 2} values of 0.9937-1.0000) and reproducibility of elution times (relative standard deviations, RSDs, <1.1%) and peak areas (RSDs, <10.7%) for all target compounds. Further, sample purification using Oasis HLB and Oasis MCX cartridges significantly decreased the ion-suppressing effects of biological matrix as compared to the purification using only Oasis HLB cartridge. The optimized nanoflow-LC-ESI-IT-MS/MS method was successfully used to analyze endogenous plant hormones in Arabidopsis and tobacco samples. The samples used in this analysis were extracted from only 17 tobacco dry seeds (1 mg DW), indicating that the efficiency of analysis of endogenous plant hormones strongly depends on the detection sensitivity of the method. Our analytical approach will be useful for in-depth studies on complex plant hormonal metabolism.

KARAKTERISASI SIFAT-SIFAT BIOKIMIA EKSTRAK KASAR LIPASE EKSTRASELULER BAKTERI Azospirillum sp.PRD1

Directory of Open Access Journals (Sweden)

Santi Nur Handayani

2011-11-01

Full Text Available Enzim lipase mempunyai peranan penting dalam katalis berbagai reaksi industri satu diantaranya pembuatan flavor melalui reaksi esterifikasi. Lipase adalah biokatalis yang berperan besar dalam aplikasi bioteknologi, seperti dalam sintesis biopolimer, biodiesel, produksi obat, dan produksi flavor. Peningkatan penggunaan lipase untuk industri mendorong dilakukan penelitian untuk mendapatkan sumber-sumber lipase baru. Sumber lipase yang potensial salah satunya adalah bakteri Azospirillum sp.PRD1 dari isolat lokal Laboratorium Mikrobiologi, Fakultas Biologi Universitas Jenderal Soedirman. Tujuan penelitian adalah untuk mendapatkan ekstrak kasar lipase dan menentukan karakteristik sifat-sifat biokimiawinya. Metode yang digunakan antara lain peremajaan bakteri Azospirillum sp.PRD1, dan produksi inokulum, penentuan waktu produksi optimum dan fase pertumbuhan bakteri, ekstraksi dan produksi ekstrak kasar lipase dan penentuan karakteristik sifat-sifat biokimiawinya. Hasil penelitian diperoleh ekstrak kasar lipase dari inokulum berumur 7 jam dan medium produksi dengan induser minyak zaitun yang diinkubasi selama 3 jam memiliki aktivitas spesifik 7,0547 Unit/mg. Lipase ekstrak kasar optimum pada pH 7, suhu 40 oC dan waktu inkubasi selama 25 menit. Lipase merupakan metaloenzim dengan kofaktor Zn2+ , Mn2+, Hg2+, Ca2+, Co2+ and Mg2+.

Epinephrine as a metabolic regulatory hormone in irradiated rats

International Nuclear Information System (INIS)

Mohamed, M.A.; Saada, H.N.; Roushdy, H.M.; Awad, O.M.; El-Sayed, M.M.; Azab, Kh.Sh.

1997-01-01

The role of epinephrine as a regulatory hormone was examined in normal and irradiated rats. Epinephrine was intraperitoneally injected into rats at a concentration of 200 Mg/kg body weight. Epinephrine was injected either 15 minutes before or just after whole body gamma irradiation 6 Gy 9 single dose). The variations in serum epinephrine,norepinephrine, triglycerides,lipase activity, glucose and lactic acid were selected as biochemical markers in this study. Biochemical estimations were undertaken at 1 hr, 4 hrs. 1,3 and 7 days treatment (after irradiation). The data obtained revealed that the treatment of normal rats with epinephrine induced a significant increase in serum epinephrine level 1 hr after injection, while the level of norepinephrine significantly increased at 4 hrs. Lipase activity significantly increased on the 1 ST hr post treatment. A significant decrease in the level of triglycerides was recorded 1 and 4 hrs post treatment. Serum glucose significantly increased at 1 and 4 hrs post treatment, while no significant changes were recorded for lactic acid. In gamma irradiated rats, the level of serum epinephrine significantly decreased at 1 hr followed by significant increases recorded at 1,3, and 7 days after irradiation. Norepinephrine levels significantly decreased after irradiation during all the experimental time periods. The levels of triglycerides show significant increases accompanied by decrease in lipase activity

Yeast Kluyveromyces lactis as host for expression of the bacterial lipase: cloning and adaptation of the new lipase gene from Serratia sp.

Science.gov (United States)

Šiekštelė, Rimantas; Veteikytė, Aušra; Tvaska, Bronius; Matijošytė, Inga

2015-10-01

Many microbial lipases have been successfully expressed in yeasts, but not in industrially attractive Kluyveromyces lactis, which among other benefits can be cultivated on a medium supplemented with whey--cheap and easily available industrial waste. A new bacterial lipase from Serratia sp. was isolated and for the first time expressed into the yeast Kluyveromyces lactis by heterologous protein expression system based on a strong promoter of Kluyveromyces marxianus triosephosphate isomerase gene and signal peptide of Kluyveromyces marxianus endopolygalacturonase gene. In addition, the bacterial lipase gene was synthesized de novo by taking into account a codon usage bias optimal for K. lactis and was expressed into the yeast K. lactis also. Both resulting strains were characterized by high output level of the target protein secreted extracellularly. Secreted lipases were characterized for activity and stability.

Anti- and Pro-Lipase Activity of Selected Medicinal, Herbal and Aquatic Plants, and Structure Elucidation of an Anti-Lipase Compound

Directory of Open Access Journals (Sweden)

Muhammad Abubakar Ado

2013-11-01

Full Text Available Plants that help in slowing down the digestion of triacylglycerols (TAGs in the pancreas and small intestine of humans play an important role in the reduction of obesity. On the other hand, there may be plants or plant parts that stimulate intestinal lipolytic activity, thus contributing to greater TAG assimilation. The aim of this study was to evaluate the aqueous methanolic extracts of ninety eight (98 medicinal, herbal and aquatic plant materials from Malaysia for their effect on porcine pancreatic lipase (PPL activity and to identify the structure of an anti-lipase compound from one of the sources. The degree of inhibition was also quantified as relative to orlistat activity against PPL (orlistat equivalents. Results revealed that while 19.4% of the extracts were found to have anti-lipase activity ≥80%, 12% were actually found to promote PPL activity. Twenty two percent (22.4% exhibited moderate inhibition (41%–80% and 2% were neutral toward PPL activity. The ripe fruit of Averrhoa carambola and the leaves of Archidendron jiringa (Jack I.C Nielsen L. (jering, Cynometra cauliflora (nam-nam and Aleurites moluccana (L. Willd (candle nut/buah keras had the highest (100% anti-lipase activity and are equivalent to 0.11 µg orlistat/mL. Plants that stimulated lipase activity included Pimpinella anisum L. (aniseed/jintan manis, activating the enzyme by 186.5%. Kaempferol 3-O-rhamnoside was isolated from the ethyl acetate fraction of C. cauliflora leaves and found to be an active lipase inhibitor. The structure was elucidated using 1H-NMR, 13C-NMR and 2D-NMR analyses.

Serum Lipase as Clinical Laboratory Index for Chronic Renal Failure Diagnosis.

Science.gov (United States)

Zhu, Ying; Dong, Jing; Wang, Ping; Huang, Huifang; Jin, Xiaohua; Zhou, Jingou; Shi, Jingfang; Gu, Guohao; Chen, Jun; Xu, Jun; Song, Yanhui

2016-07-01

Measuring the level of serum lipase has been used for the clinical diagnosis of acute pancreatitis. Reports showed that the serum lipase level increased in patients of clinical renal failure. In this study, we aimed to measure the change of serum lipase levels in chronic kidney diseases and determine whether it could serve as a clinical laboratory index for clinical renal failure diagnosis. Materials: The OLYMPUS AU5400 automatic biochemical analyzer was used to determine the serum levels of lipase and creatinine. The study included 120 cases in the clinical renal failure group, 76 cases in the nephrotic syndrome group, 81 cases in the chronic nephritis group, and 80 healthy controls from our hospital volunteers in the same period. We then compared the lipase levels and conducted statistical analyses among these groups. The serum lipase levels were 15.3 U/L, 79.8 U/L, 45.1 U/L, and 51.0 U/L in the normal control, clinical renal failure, nephrotic syndrome, and chronic nephritis groups, respectively. The lipase levels in the groups with diseases were significantly different compared with that of the normal control group (p renal failure group was significantly higher than that of the nephrotic syndrome group and chronic nephritis group (p chronic nephritis group (p > 0.05) was observed. Moreover, an association of the serum lipase with disease progression was observed in the study. Serum lipase is an effective serological index which can reflect the clinical changes in the clinical renal failure and tends to increase through the progression of renal dysfunction.

Extracellular and intracellular steroid binding proteins

International Nuclear Information System (INIS)

Wagner, R.K.

1978-01-01

Steroid hormone binding proteins can be measured, after the removal of endogenous steroids, as specific complexes with radio-labelled hormones. In this study all the requirements for a quantitative determination of steroid hormone binding proteins are defined. For different methods, agargel electrophoresis, density gradient centrifugation, equilibrium dialysis and polyacrylamide electrophoresis have been evaluated. Agar electrophoresis at low temperature was found to be the simplest and most useful procedure. With this method the dissociation rates of high affinity complexes can be assessed and absolute binding protein concentrations can be determined. The dissociation rates of the oestradiol-oestrogen receptor complex and the R-5020-progestin receptor complex are low (1-2% per h run time.) In contrast, that of complexes between androgen receptor and dihydrotestosterone (17β-hydroxy-5α-androstan-3-one (DHT), progestin receptor and progesterone, corticosteroid binding globulin (CBG) and cortisol or progesterone and sex hormone binding globulin (SHBG) and DHT were hign (16-27% per h run time). Target tissue extracts (cytosols) contain, besides soluble tissue proteins, large amounts of plasma proteins. The extent of this plasma contamination can be determined by measuring the albumin concentration in cytosols by immunodiffusion. In cytosols of 4 different human target tissues the albumin content varied from 20-30% corresponding to an even higher whole plasma concentration. Steroid binding plasma proteins, such as CBG and SHBG are constituents of this containment. (author)

Enhancement of lipase catalyzed-fatty acid methyl esters production from waste activated bleaching earth by nullification of lipase inhibitors.

Science.gov (United States)

Dwiarti, Lies; Ali, Ehsan; Park, Enoch Y

2010-01-01

This study sought to identify inhibitory factors of lipase catalyzed-fatty acid methyl esters (FAME) production from waste activated bleaching earth (wABE). During the vegetable oil refinery process, activated bleaching earth (ABE) is used for removing the impure compounds, but adsorbs vegetable oil up to 35-40% as on a weight basis, and then the wABE is discarded as waste material. The impurities were extracted from the wABE with methanol and evaluated by infra-red (IR) spectroscopy, which revealed that some were chlorophyll-plant pigments. The chlorophylls inhibited the lipase during FAME conversion from wABE. The inhibition by a mixture of chlorophyll a and b was found to be competitive. The inhibition of the enzymatic hydrolysis of waste vegetable oil contained in wABE by chlorophyll a alone was competitive, while the inhibition by chlorophyll b alone was non-competitive. Furthermore, the addition of a small amount of alkali nullified this inhibitory effect and accelerated the FAME production rate. When 0.9% KOH (w/w wABE) was added to the transesterification reaction with only 0.05% lipase (w/w wABE), the maximum FAME production rate improved 120-fold, as compared to that without the addition of KOH. The alkali-combined lipase significantly enhanced the FAME production rate from wABE, in spite of the presence of the plant pigments, and even when a lower amount of lipase was used as a catalyst.

Lipase catalyzed ester synthesis for food processing industries

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Aravindan Rajendran

2009-02-01

Full Text Available Lipases are one of the most important industrial biocatalyst which catalyzes the hydrolysis of lipids. It can also reverse the reaction at minimum water activity. Because of this pliable nature, it is widely exploited to catalyze the diverse bioconversion reactions, such as hydrolysis, esterification, interesterification, alcoholysis, acidolysis and aminolysis. The property to synthesize the esters from the fatty acids and glycerol promotes its use in various ester synthesis. The esters synthesized by lipase finds applications in numerous fields such as biodiesel production, resolution of the recemic drugs, fat and lipid modification, flavour synthesis, synthesis of enantiopure pharmaceuticals and nutraceuticals. It plays a crucial role in the food processing industries since the process is unaffected by the unwanted side products. Lipase modifications such as the surfactant coating, molecular imprinting to suit for the non-aqueous ester synthesis have also been reported. This review deals with lipase catalyzed ester synthesis, esterification strategies, optimum conditions and their applications in food processing industries.Lipases são catalizadores industriais dos mais importantes, os quais catalizam a hidrólise de lipídeos. Também podem reverter a reação a um mínimo de atividade de água. Devido sua natureza flexível, é amplamente explorada para catalizar uma diversidade de reações de bioconversão como hidrólise, esterificação, interesterificação, alcoólise, acidólise e aminólise. A propriedade de síntese de esteres a partir de ácidos graxos e glicerol promoveu seu uso em várias sínteses de esteres. Os esteres sintetizados por lipases encontram aplicação em numerosos campos como a produção de biodiesel, resolução de drogas racêmicas, modificação de gorduras e lipídios, sintese de aromas, síntese de produtos farmacêuticos enantiopuro e nutracêuticos. As lipases possuem um papel crucial nas indústrias de

125I-luteinizing hormone (LH) binding to soluble receptors from the primate (Macaca mulatta) corpus luteum: effects of ethanol exposure

International Nuclear Information System (INIS)

Danforth, D.R.; Stouffer, R.L.

1988-01-01

In the current study, we compared the effects of ethanol on gonadotropin receptors solubilized from macaque luteal membranes to those on receptors associated with the lipid bilayer. Treatment with 1% Triton X-100 for 30 min at 4C, followed by precipitation with polyethylene glycol, resulted in recovery of 50% more binding sites for 125 I-human luteinizing hormone (hLH) than were available in particulate preparations. However, the soluble receptors displayed a 3-fold lower affinity for 125 I-hLH. Conditions which enhanced LH binding to particulates, i.e., 1-8% ethanol at 25C, decreased specific 125 I-hLH binding to soluble receptors. Steady-state LH binding to soluble receptors during incubation at 4C was half of that observed at 25C. The presence of 8% ethanol at 4C restored LH binding to levels observed in the absence of ethanol at 25C. Thus, LH binding sites in the primate corpus luteum can be effectively solubilized with Triton X-100. The different binding characteristics of particulate and soluble receptors, including the response to ethanol exposure, suggest that the lipid environment in the luteal membrane modulates the availability and affinity of gonadotropin receptors

Actin-Sorting Nexin 27 (SNX27)-Retromer Complex Mediates Rapid Parathyroid Hormone Receptor Recycling*

Science.gov (United States)

McGarvey, Jennifer C.; Xiao, Kunhong; Bowman, Shanna L.; Mamonova, Tatyana; Zhang, Qiangmin; Bisello, Alessandro; Sneddon, W. Bruce; Ardura, Juan A.; Jean-Alphonse, Frederic; Vilardaga, Jean-Pierre; Puthenveedu, Manojkumar A.; Friedman, Peter A.

2016-01-01

The G protein-coupled parathyroid hormone receptor (PTHR) regulates mineral-ion homeostasis and bone remodeling. Upon parathyroid hormone (PTH) stimulation, the PTHR internalizes into early endosomes and subsequently traffics to the retromer complex, a sorting platform on early endosomes that promotes recycling of surface receptors. The C terminus of the PTHR contains a type I PDZ ligand that binds PDZ domain-containing proteins. Mass spectrometry identified sorting nexin 27 (SNX27) in isolated endosomes as a PTHR binding partner. PTH treatment enriched endosomal PTHR. SNX27 contains a PDZ domain and serves as a cargo selector for the retromer complex. VPS26, VPS29, and VPS35 retromer subunits were isolated with PTHR in endosomes from cells stimulated with PTH. Molecular dynamics and protein binding studies establish that PTHR and SNX27 interactions depend on the PDZ recognition motif in PTHR and the PDZ domain of SNX27. Depletion of either SNX27 or VPS35 or actin depolymerization decreased the rate of PTHR recycling following agonist stimulation. Mutating the PDZ ligand of PTHR abolished the interaction with SNX27 but did not affect the overall rate of recycling, suggesting that PTHR may directly engage the retromer complex. Coimmunoprecipitation and overlay experiments show that both intact and mutated PTHR bind retromer through the VPS26 protomer and sequentially assemble a ternary complex with PTHR and SNX27. SNX27-independent recycling may involve N-ethylmaleimide-sensitive factor, which binds both PDZ intact and mutant PTHRs. We conclude that PTHR recycles rapidly through at least two pathways, one involving the ASRT complex of actin, SNX27, and retromer and another possibly involving N-ethylmaleimide-sensitive factor. PMID:27008860

Emulsifying triglycerides with dairy phospholipids instead of soy lecithin modulates gut lipase activity

DEFF Research Database (Denmark)

Mathiassen, Jakob Hovalt; Nejrup, Rikke Guldhammer; Frøkiær, Hanne

2015-01-01

in particular to limit fatty acid absorption in babies given infant formulas. Since interaction between the lipid droplet and the gastric and duodenal lipases occur through the hydrophobic/hydrophilic interface, the composition of the emulsifier may be crucial for efficient hydrolysis. We therefore determined...... hydrolytic rate of gastric lipase and pancreatic lipase, on their own or pancreatic lipase after gastric lipase on TAG droplets of similar size emulsified in either soy lecithin (SL) or in bovine milk phospholipids (MPL), more similar to human milk globule membrane lipids than soy lecithin. Gastric lipase...... for formulas for term-born infants....

α-Helical element at the hormone-binding surface of the insulin receptor functions as a signaling element to activate its tyrosine kinase.

Science.gov (United States)

Whittaker, Jonathan; Whittaker, Linda J; Roberts, Charles T; Phillips, Nelson B; Ismail-Beigi, Faramarz; Lawrence, Michael C; Weiss, Michael A

2012-07-10

The primary hormone-binding surface of the insulin receptor spans one face of the N-terminal β-helix of the α-subunit (the L1 domain) and an α-helix in its C-terminal segment (αCT). Crystallographic analysis of the free ectodomain has defined a contiguous dimer-related motif in which the αCT α-helix packs against L1 β-strands 2 and 3. To relate structure to function, we exploited expanded genetic-code technology to insert photo-activatable probes at key sites in L1 and αCT. The pattern of αCT-mediated photo-cross-linking within the free and bound receptor is in accord with the crystal structure and prior mutagenesis. Surprisingly, L1 photo-probes in β-strands 2 and 3, predicted to be shielded by αCT, efficiently cross-link to insulin. Furthermore, anomalous mutations were identified on neighboring surfaces of αCT and insulin that impair hormone-dependent activation of the intracellular receptor tyrosine kinase (contained within the transmembrane β-subunit) disproportionately to their effects on insulin binding. Taken together, these results suggest that αCT, in addition to its hormone-recognition role, provides a signaling element in the mechanism of receptor activation.

Study the effect of F17S mutation on the chimeric Bacillus thermocatenulatus lipase

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Seyed Hossein Khaleghinejad

2016-06-01

Full Text Available Lipases (triacylglycerol acylhydrolase, EC 3.1.1.3 are one of the highest value commercial enzymes as they have potential applications in biotechnology for detergents, food, pharmaceuticals, leather, textiles, cosmetics, and paper industries; and are currently receiving considerable attention because of their potential applications in biotechnology. Bacillus thermocatenulatus Lipase 2 (BTL2 is one of the most important research targets, because of its potential industrial applications. In this study, the effect of substitution Phe17 with Ser in mutated BTL2 lipase, which conserved pentapeptide (112Ala-His-Ser-Gln-Gly116 was replaced with similar sequences (207Gly-Glu-Ser-Ala-Gly211 of Candida rugosa lipase (CLR at the nucleophilic elbow region. Docking results confirmed the mutated lipase to be better than the chimeric lipase. So, cloning was conducted, and the mutated and chimeric btl2 genes were expressed in Escherichia coli, and then the enzymes were purified by anion exchange chromatography. The mutation increased lipase lipolytic activity against most of the applied substrates, with the exception of tributyrin when compared with chimeric lipase. Further, the mutated lipase exhibited higher activity than the chimeric lipase at all temperatures. Optimum pH of the mutated lipase was obtained at pH 9.5, which was more than the chimeric one. Enzyme activity of the mutated lipase in the presence of organic solvents, detergents, and metal ions was also improved than the chimeric lipase.

A lipase with broad temperature range from an alkaliphilic gamma-proteobacterium isolated in Greenland

DEFF Research Database (Denmark)

Schmidt, Mariane; Larsen, Dorte Møller; Stougaard, Peter

2010-01-01

A gamma-proteobacterium related to the genera Alteromonadales and Pseudomonadales , isolated from a cold and alkaline environment in Greenland, has been shown to produce a lipase active between 5 ° C and 80 ° C, with optimal activity at 55 ° C and pH 8. PCR-based screening of genomic DNA from...... the isolated bacterium, followed by genome walking, resulted in two complete open reading frames, which were predicted to encode a lipase and its helper protein, a lipase foldase. The amino acid sequence derived for the lipase showed resemblance to lipases from Pseudomonas , Rhodoferax, Aeromonas and Vibrio...... . The two genes were cloned into different expression systems in E. coli with or without a putative secretion sequence, but despite the fact that both recombinant lipase and lipase foldase were observed on SDS–PAGE, no recombinant lipase activity was detected. Attempts to refold the recombinant lipase...

A portion of heifers attaining “early puberty” do not display estrus, are anovulatory and have altered sex hormone binding globulin concentrations

Science.gov (United States)

Cows with excess androstenedione (High A4) in the follicular fluid of dominant follicles attain puberty earlier than their low androstenedione counterparts. Furthermore, High A4 cows are anovulatory (chronic or sporadic) and have lower Sex Hormone Binding Globulin (SHBG) compared to Low A4 ovulator...

Dissecting adipose tissue lipolysis: molecular regulation and implications for metabolic disease

DEFF Research Database (Denmark)

Nielsen, Thomas Svava; Jessen, Niels; Jørgensen, Jens Otto Lunde

2014-01-01

is tightly regulated by hormonal and nutritional factors. Under conditions of negative energy balance such as fasting and exercise, stimulation of lipolysis results in a profound increase in FFA release from adipose tissue. This response is crucial in order to provide the organism with a sufficient supply......Lipolysis is the process by which triglycerides are hydrolyzed to free fatty acids (FFA) and glycerol. In adipocytes, this is achieved by the sequential action of Adipose Triglyceride Lipase (ATGL), Hormone Sensitive Lipase (HSL) and Monoglyceride Lipase (MGL). The activity in the lipolytic pathway...... of substrate for oxidative metabolism. However, failure to efficiently suppress lipolysis when FFA demands are low can have serious metabolic consequences and is believed to be a key mechanism in the development of type 2 diabetes in obesity. Since the discovery of ATGL in 2004, substantial progress has been...

Desempenho de diferentes lipases imobilizadas na síntese de biodiesel de óleo de palma = Performance of different immobilized lipases in palm oil biodiesel synthesis

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Grazielle dos Santos Silva

2011-04-01

Full Text Available O presente trabalho teve como objetivo determinar as condicoes otimizadas da sintese enzimatica de biodiesel, a partir do oleo de palma e etanol, empregando diferentes lipases imobilizadas (lipase de Pseudomonas fluorescens imobilizada em SiO2-PVA e lipase de Candida antartica imobilizada em resina acrilica - Novozym„µ 435 em meio isento de solvente. Uma matriz de planejamento fatorial foi utilizada para avaliar a influencia da temperatura (42 ¡V 58„aC e a razao molar entre etanol e oleo de palma (6:1 ¡V 18:1 no rendimento detransesterificacao alcancado para cada preparacao de lipase. Os efeitos principais foram ajustados por analise de regressao multipla a modelos lineares e o rendimento maximo foi obtido quando o sistema operacional foi operado a 42„aC com substratos contendo etanol eoleo de palma na razao molar de 18:1. Os modelos matematicos que representam o rendimento global da reacao para cada lipase imobilizada foram considerados adequados para descrever os resultados experimentais.Optimized conditions for palm oil and ethanol enzymatic biodiesel synthesis were determined with different immobilized lipases SiO2-PVA-immobilized lipase from Pseudomonas fluorescens and acrylic resin-immobilized lipase, NovozymR435, from Candida antartica, in solvent-free medium. A full factorial design assessed the influence oftemperature (42 ¡V 58¢XC and ethanol: palm oil (6:1 ¡V 18:1 molar ratio on the transesterification yield. Main effects were adjusted by multiple regression analysis to linear models and the maximum transesterification yield was obtained at 42¢XC and 18:1 ethanol:palm oil molar ratio. Mathematical models featuring total yield for each immobilized lipase were suitable to describe the experimental results.

AKTIVITAS HIDROLISIS ENZIM LIPASE DARI KENTOS KELAPA TERHADAP MINYAK KELAPA Hidrolysis Activity of Lipase Enzyme from Coconut Houstorium for Coconut Oil

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Mohammad Su’i

2012-05-01

Full Text Available This research was aimed to study hydrolysis conditions of houstorium lipases enzyme using coconut oil as substrate. Hydrolysis conditions studied were substrate (coconut oil concentration, enzyme substrate ratio, duration of hydro- lysis and effect of stirring to hydrolysis. The results show  that lipase of coconut houstorium may be optimally used at a coconut oil concentration of 10 %, enzyme to substrate ratio of 3 : 10 (v/v and hydrolysis for 60 minutes with stirring. ABSTRAK Penelitian ini mempelajari kondisi hidrolisis minyak kelapa yang optimum menggunakan enzim lipase dari kentos kelapa. Kondisi hidrolisis yang dipelajari meliputi konsentrasi substrat optium, perbandingan enzim : substrat dan lama hidrolisis yang optimum serta pengaruh pengadukan selama hidrolisis. Hasil penelitian menunjukkan bahwa, hidrolisis minyak kelapa menggunakan enzim lipase kentos kelapa menghasilkan asam lemak bebas paling banyak pada kon- sentrasi substrat (minyak kelapa 10 %, perbandingan enzim : substrat yaitu 3 : 10 (v/v, lama hidroloisa 60 menit dan dilakukan pengadukan selama hidrolisis.

Streptomyces rimosus GDS(L Lipase: Production, Heterologous Overexpression and Structure-Stability Relationship

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Marija Abramić

2003-01-01

Full Text Available Streptomyces rimosus lipase gene has been overexpressed in a heterologous host, S. lividans TK23. The maximal lipase activity was determined in the culture filtrates of the late stationary phase. Time course of lipase production was monitored by a modified plate assay. S. rimosus lipase gene has been located on the AseI B fragment approximately 2 Mb far from the left end of the S. rimosus linear chromosome. Out of eight examined streptomycetes, the presence of this rare type of bacterial lipase gene was detected in two belonging to the S. rimosus taxonomic cluster, and in one non-related species. Comparison of protein sequences of the Streptomyces lipolytic enzymes was performed. The result indicated the best structural stability of the putative S. coelicolor lipase-2.

A Quantitative Fluorescence-Based Lipase Assay

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Giovanna Lomolino

2012-01-01

Full Text Available An easy and fast gel diffusion assay for detecting and monitoring lipase activity by quantification of fluorescein is described. By measuring the intensity of fluorescein, it is possible to obtain a calibration curve with a regression coefficient better than by using the radius of fluorescent haloes. Through the quantification of fluorescence intensity of fluorescein released after the hydrolysis of a fluorescent ester, fluorescein dibutyrate, used as substrate in agar plates, commercial and skimmed milk lipase activity were studied. Moreover, with this method, lipase activity can be monitored in reaction medium that contains compounds which are affected by turbidity or cause measurement interference for UV-spectrophotometer and fluorimeter. In this experiment, boiled skimmed milk was dispersed in the agar gel with fluorescein dibutyrate, and it was used as a reaction medium to mimic natural conditions. The development of such an assay has a potential for applications in industries ranging from pharmaceuticals to food production and monitoring.

Gamma-irradiation sterilization of lipases for cheese making

Energy Technology Data Exchange (ETDEWEB)

Umanskij, M S; Borovkova, Yu A; Odegov, N I [Vsesoyuznyj Nauchno-Issledovatel' skij Inst. Maslodel' noj i Syrodel' noj Promyshlennosti, Uglich (USSR)

1979-03-01

The possibility of sterilizing the enzyme compounds of lipases from Oospora fragrans strains by gamma irradiation was studied. The enzyme compounds were exposed to gamma irradiation at the doses from 0.1 to 0.8 Mrad with the discreteness of 0.1 Mrad and at the dose of 2.0 Mrad. After the radiation treatment the lipases were investigated for bacterial invasion by the cultivation method and for the lipolytic activity by the titrometrical method. It is shown that the sterilization effect is achieved without losses of lipase activity and the radiation dose necessary for sterilization depends on initial invasion levels in the enzyme compounds.

Solubilization and molecular size of atrial natriuretic hormone (ANH) receptors from rabbit aorta, renal cortex and adrenal

International Nuclear Information System (INIS)

Budzik, G.P.; Bush, E.N.; Holleman, W.H.

1986-01-01

ANH(1-28) is presumed to regulate blood pressure and fluid balance via membrane receptors coupled to particulate guanylate cyclase. ANH receptors were solubilized from rabbit aorta, renal cortex and adrenal, primary ANH targets. Plasma membranes extracted with 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate(CHAPS) yield solubilized receptors with high affinity binding of 125 I-Tyr 28 -ANH. Degradation of hormone was minimized with a broad spectrum of protease inhibitors. 125 I-ANH binding reached maximum by 1 hr at 0 0 C and was stable for at least an additional 2 hrs. Bound was separated from free ligand by HPLC gel filtration on TSK-3000SW in PBS/CHAPS. Bound hormone eluted at a MW of ∼ 200KD in each tissue preparation and was displaced by unlabelled ANH. The concentration of solubilized binding sites was proportional to densities in intact plasma membranes, i.e., adrenal > renal > aorta. Following separation of free hormone, 125 I-ANH-receptors complexes were coupled using bifunctional crosslinking reagents. SDS-PAGE analysis and autoradiography indicated a major labelled band at ∼ 150KD in each tissue preparation. The mobility of this labelled band was not sensitive to reduction before SDS-PAGE. Although these results suggest that solubilized ANH receptors from primary target tissues are very similar, microheterogeneity affecting binding affinity or signal transduction cannot as yet be excluded

Selection and optimization of extracellular lipase production using ...

African Journals Online (AJOL)

The aim of this study was to isolate and select lipase-producing microorganisms originated from different substrates, as well as to optimize the production of microbial lipase by submerged fermentation under different nutrient conditions. Of the 40 microorganisms isolated, 39 showed a halo around the colonies and 4 were ...

Optimization of lipase production by Staphylococcus sp. Lp12

African Journals Online (AJOL)

USER

2010-02-08

Feb 8, 2010 ... an enormous attention because of their biotechnological applications. Lipases remain ... selective transformations. The exponential increase in .... mass) lipase production and pH at regular intervals of time 24, 48 and 72 h on ...

New lipases by mining of Pleurotus ostreatus genome.

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Alessandra Piscitelli

Full Text Available The analysis of Pleurotus ostreatus genome reveals the presence of automatically annotated 53 lipase and 34 carboxylesterase putative coding-genes. Since no biochemical or physiological data are available so far, a functional approach was applied to identify lipases from P. ostreatus. In the tested growth conditions, four lipases were found expressed, with different patterns depending on the used C source. Two of the four identified proteins (PleoLip241 and PleoLip369, expressed in both analysed conditions, were chosen for further studies, such as an in silico analysis and their molecular characterization. To overcome limits linked to native production, a recombinant expression approach in the yeast Pichia pastoris was applied. Different expression levels were obtained: PleoLip241 reached a maximum activity of 4000 U/L, whereas PleoLip369 reached a maximum activity of 700 U/L. Despite their sequence similarity, these enzymes exhibited different substrate specificity and diverse stability at pH, temperature, and presence of metals, detergents and organic solvents. The obtained data allowed classifying PleoLip241 as belonging to the "true lipase" family. Indeed, by phylogenetic analysis the two proteins fall in different clusters. PleoLip241 was used to remove the hydrophobic layer from wool surface in order to improve its dyeability. The encouraging results obtained with lipase treated wool led to forecast PleoLip241 applicability in this field.

Mycobacterium tuberculosis Ku can bind to nuclear DNA damage and sensitize mammalian cells to bleomycin sulfate.

Science.gov (United States)

Castore, Reneau; Hughes, Cameron; Debeaux, Austin; Sun, Jingxin; Zeng, Cailing; Wang, Shih-Ya; Tatchell, Kelly; Shi, Runhua; Lee, Kyung-Jong; Chen, David J; Harrison, Lynn

2011-11-01

Radiotherapy and chemotherapy are effective cancer treatments due to their ability to generate DNA damage. The major lethal lesion is the DNA double-strand break (DSB). Human cells predominantly repair DSBs by non-homologous end joining (NHEJ), which requires Ku70, Ku80, DNA-PKcs, DNA ligase IV and accessory proteins. Repair is initiated by the binding of the Ku heterodimer at the ends of the DSB and this recruits DNA-PKcs, which initiates damage signaling and functions in repair. NHEJ also exists in certain types of bacteria that have dormant phases in their life cycle. The Mycobacterium tuberculosis Ku (Mt-Ku) resembles the DNA-binding domain of human Ku but does not have the N- and C-terminal domains of Ku70/80 that have been implicated in binding mammalian NHEJ repair proteins. The aim of this work was to determine whether Mt-Ku could be used as a tool to bind DSBs in mammalian cells and sensitize cells to DNA damage. We generated a fusion protein (KuEnls) of Mt-Ku, EGFP and a nuclear localization signal that is able to perform bacterial NHEJ and hence bind DSBs. Using transient transfection, we demonstrated that KuEnls is able to bind laser damage in the nucleus of Ku80-deficient cells within 10 sec and remains bound for up to 2 h. The Mt-Ku fusion protein was over-expressed in U2OS cells and this increased the sensitivity of the cells to bleomycin sulfate. Hydrogen peroxide and UV radiation do not predominantly produce DSBs and there was little or no change in sensitivity to these agents. Since in vitro studies were unable to detect binding of Mt-Ku to DNA-PKcs or human Ku70/80, this work suggests that KuEnls sensitizes cells by binding DSBs, preventing human NHEJ. This study indicates that blocking or decreasing the binding of human Ku to DSBs could be a method for enhancing existing cancer treatments.

Rhizomucor miehei triglyceride lipase is processed and secreted from transformed Aspergillus oryzae.

Science.gov (United States)

Huge-Jensen, B; Andreasen, F; Christensen, T; Christensen, M; Thim, L; Boel, E

1989-09-01

The cDNA encoding the precursor of the Rhizomucor miehei triglyceride lipase was inserted in an Aspergillus oryzae expression vector. In this vector the expression of the lipase cDNA is under control of the Aspergillus oryzae alpha-amylase gene promoter and the Aspergillus niger glucoamylase gene terminator. The recombinant plasmid was introduced into Aspergillus oryzae, and transformed colonies were selected and screened for lipase expression. Lipase-positive transformants were grown in a small fermentor, and recombinant triglyceride lipase was purified from the culture broth. The purified enzymatically active recombinant lipase (rRML) secreted from A. oryzae was shown to have the same characteristics with respect to mobility on reducing SDS-gels and amino acid composition as the native enzyme. N-terminal amino acid sequencing indicated that approximately 70% of the secreted rRML had the same N-terminal sequence as the native Rhizomucor miehei enzyme, whereas 30% of the secreted rRML was one amino acid residue shorter in the N-terminal. The recombinant lipase precursor, which has a 70 amino acid propeptide, is thus processed in and secreted from Aspergillus oryzae. We have hereby demonstrated the utility of this organism as a host for the production of recombinant triglyceride lipases.

High cell density fed-batch fermentations for lipase production: feeding strategies and oxygen transfer.

Science.gov (United States)

Salehmin, M N I; Annuar, M S M; Chisti, Y

2013-11-01

This review is focused on the production of microbial lipases by high cell density fermentation. Lipases are among the most widely used of the enzyme catalysts. Although lipases are produced by animals and plants, industrial lipases are sourced almost exclusively from microorganisms. Many of the commercial lipases are produced using recombinant species. Microbial lipases are mostly produced by batch and fed-batch fermentation. Lipases are generally secreted by the cell into the extracellular environment. Thus, a crude preparation of lipases can be obtained by removing the microbial cells from the fermentation broth. This crude cell-free broth may be further concentrated and used as is, or lipases may be purified from it to various levels. For many large volume applications, lipases must be produced at extremely low cost. High cell density fermentation is a promising method for low-cost production: it allows a high concentration of the biomass and the enzyme to be attained rapidly and this eases the downstream recovery of the enzyme. High density fermentation enhances enzyme productivity compared with the traditional submerged culture batch fermentation. In production of enzymes, a high cell density is generally achieved through fed-batch operation, not through perfusion culture which is cumbersome. The feeding strategies used in fed-batch fermentations for producing lipases and the implications of these strategies are discussed. Most lipase-producing microbial fermentations require oxygen. Oxygen transfer in such fermentations is discussed.

Binding properties of beetal recombinant caprine growth hormone to ...

African Journals Online (AJOL)

SAM

2014-07-23

Jul 23, 2014 ... The aim of the study was to illustrate the radio-receptor assay of beetal recombinant caprine growth hormone (rcGH) ... interaction with microsomal membrane that shall be beneficial to study hormone receptor interactions of other Bovidae .... adding 1 ml of ice cold assay buffer, followed by 1 ml of 25% (w/v).

Lipase polystyrene giant amphiphiles.

Science.gov (United States)

Velonia, Kelly; Rowan, Alan E; Nolte, Roeland J M

2002-04-24

A new type of giant amphiphilic molecule has been synthesized by covalently connecting a lipase enzyme headgroup to a maleimide-functionalized polystyrene tail (40 repeat units). The resulting biohybrid forms catalytic micellar rods in water.

Evolutionary aspects of growth hormones and prolactins and their receptors

International Nuclear Information System (INIS)

Tarpey, J.F.

1986-01-01

The interactions of GH's, PRL's and PL's with receptors for GH and PRL were examined from a comparative and evolutionary viewpoint. The binding of 125 I-bGH to membrane preparations from liver of representatives of the major classes of non-mammalian vertebrates was also studied. Only hepatic membranes from sturgeon and Gillichthys had significant bGH binding and were further characterized and compared with male rabbit liver membranes in terms of time, temperature, pH, and membrane concentration to optimize binding conditions. The binding of several members of the GH, PRL, PL family of hormones to GH receptors from liver of sturgeon, Gillichthys, rabbit, mouse and rat was investigated. in terms of hormonal specificity, the mammalian receptors and the sturgeon binding sites were similar, while Gillichthys receptors had a different pattern of hormonal specificity. The binding of 125 I-oPRL to renal membranes of the turtle, Pseudemys scripta elegans, was characterized and compared to PRL binding sites of kidney membranes of the bullfrog, Rana catesbeiana, and the tiger salamander, Ambystoma tigrinum

Sex hormones in postmenopausal women with primary biliary cirrhosis

DEFF Research Database (Denmark)

Becker, U; Almdal, Thomas Peter; Christensen, E

1991-01-01

To evaluate serum sex hormone profiles in nonalcoholic postmenopausal women with liver disease, 25 women with primary biliary cirrhosis (11 in cirrhotic stage) and 46 healthy controls were studied. The patients had significantly (p less than 0.05) elevated serum concentrations of estrone and andr......To evaluate serum sex hormone profiles in nonalcoholic postmenopausal women with liver disease, 25 women with primary biliary cirrhosis (11 in cirrhotic stage) and 46 healthy controls were studied. The patients had significantly (p less than 0.05) elevated serum concentrations of estrone...... and androstenedione and significantly (p less than 0.05) lower concentrations of estrone sulfate, dehydroepiandrosterone sulfate and 5 alpha-dihydrotestosterone compared with the 46 controls. Serum concentrations of sex hormone binding globulin, testosterone, non-sex hormone binding globulin-bound testosterone...... and non-protein-bound testosterone did not differ significantly (p greater than 0.05) between primary biliary cirrhosis patients and controls. Patients in the cirrhotic stage had significantly (p less than 0.05) higher concentrations of sex hormone binding globulin than did controls. Patients...

Plant latex lipase as biocatalysts for biodiesel production | Mazou ...

African Journals Online (AJOL)

Plant latex lipase as biocatalysts for biodiesel production. ... This paper provides an overview regarding the main aspects of latex, such as the reactions catalyzed, physiological functions, specificities, sources and their industrial applications. Keywords: Plant latex, lipase, Transesterification, purification, biodiesel ...

Isolation and characterization of lipase-producing Bacillus strains ...

African Journals Online (AJOL)

Bacillus strains (B1 - B5) producing extra cellular lipase were isolated from the soil sample of coconut oil industry. The strains were identified by morphological and biochemical characters. Growth of the organisms and lipase production were measured with varying pH (4 - 9) temperature (27, 37 and 47ºC) and various ...

Sex-dependent expression of caveolin 1 in response to sex steroid hormones is closely associated with development of obesity in rats.

Directory of Open Access Journals (Sweden)

Rajib Mukherjee

Full Text Available Caveolin-1 (CAV1 is a conserved group of structural membrane proteins that form special cholesterol and sphingolipid-rich compartments, especially in adipocytes. Recently, it has been reported that CAV1 is an important target protein in sex hormone-dependent regulation of various metabolic pathways, particularly in cancer and diabetes. To clarify distinct roles of CAV1 in sex-dependent obesity development, we investigated the effects of high fat diet (HFD and sex steroid hormones on CAV1 expression in adipose tissues of male and female rats. Results of animal experiments revealed that estrogen (17-β-estradiol, E2 and androgen (dihydrotestosterone, DHT had opposite effects on body weight gain as well as on the regulation of CAV1, hormone sensitive lipase (HSL and uncoupling protein 1 (UCP1 in adipose tissues. Furthermore, sex hormone receptors and aromatase were differentially expressed in a sex-dependent manner in response to E2 and DHT treatments. In vivo data were confirmed using 3T3-L1 and HIB1B cell lines, where Cav1 knock down stimulated lipogenesis but suppressed sex hormone receptor signaling proteins. Most importantly, co-immunoprecipitation enabled the identification of previously unrecognized CAV1-interacting mitochondrial or lipid oxidative pathway proteins in adipose tissues. Taken together, current data showed that CAV1 may play important preventive role in the development of obesity, with more prominent effects in females, and proved to be an important target protein for the hormonal regulation of adipose tissue metabolism by manipulating sex hormone receptors and mitochondrial oxidative pathways. Therefore, we can report, for the first time, the molecular mechanism underlying the effects of sex steroid hormones in the sex-dimorphic regulation of CAV1.

Production of extracellular lipase by the phytopathogenic fungus Fusarium solani FS1 Produção de lipase extracelular pelo fungo fitopatogênico Fusarium solani FS1

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Maria de Mascena Diniz Maia

1999-12-01

Full Text Available A Brazilian strain of Fusarium solani was tested for extracellular lipase production in peptone-olive oil medium. The fungus produced 10,500 U.l-1 of lipase after 72 hours of cultivation at 25oC in shake-flask at 120 rpm in a medium containing 3% (w/v peptone plus 0.5% (v/v olive oil. Glucose (1% w/v was found to inhibit the inductive effect of olive oil. Peptone concentrations below 3% (w/v resulted in a reduced lipase production while increased olive oil concentration (above 0.5% did not further stimulate lipase production. The optimum lipase activity was achieved at pH 8.6 and 30oC and a good enzyme stability (80% activity retention was observed at pH ranging from 7.6 to 8.6, and the activity rapidly dropped at temperatures above 50oC. Lipase activity was stimulated by the addition of n-hexane to the culture medium supernatants, in contrast to incubation with water-soluble solvents.

Lipase inhibition and antiobesity effect of Atractylodes lancea.

Science.gov (United States)

Jiao, Ping; Tseng-Crank, Julie; Corneliusen, Brandon; Yimam, Mesfin; Hodges, Mandee; Hong, Mei; Maurseth, Catherine; Oh, Misun; Kim, Hyunjin; Chu, Min; Jia, Qi

2014-05-01

The ethanol extract of Atractylodes lancea rhizome displayed significant lipase inhibition with an IC50 value of 9.06 µg/mL in a human pancreatic lipase assay from high-throughput screening. Bioassay-guided isolation led to the identification of one new polyacetylene, syn-(5E,11E)-3-acetoxy-4-O-(3-methylbutanoyl)-1,5,11-tridecatriene-7,9-diyne-3,4-diol (7), along with six known compounds (1-6). The structure of compound 7 was determined based on the analysis of NMR and MS data. Among these seven lipase inhibitors, the major compound atractylodin (1) showed the highest lipase inhibitory activity (IC50 = 39.12 µM). The antiobesity effect of the ethanol extract of Atractylodes lancea rhizome was evaluated in a high-fat diet-induced obesity mice model at daily dosages of 250 mg/kg and 500 mg/kg body weight for 4 weeks, and treatment with this extract demonstrated a moderate efficacy at the 500 mg/kg dose level. Georg Thieme Verlag KG Stuttgart · New York.

ATP-modulated K+ channels sensitive to antidiabetic sulfonylureas are present in adenohypophysis and are involved in growth hormone release.

OpenAIRE

Bernardi, H; De Weille, J R; Epelbaum, J; Mourre, C; Amoroso, S; Slama, A; Fosset, M; Lazdunski, M

1993-01-01

The adenohypophysis contains high-affinity binding sites for antidiabetic sulfonylureas that are specific blockers of ATP-sensitive K+ channels. The binding protein has a M(r) of 145,000 +/- 5000. The presence of ATP-sensitive K+ channels (26 pS) has been demonstrated by electrophysiological techniques. Intracellular perfusion of adenohypophysis cells with an ATP-free medium to activate ATP-sensitive K+ channels induces a large hyperpolarization (approximately 30 mV) that is antagonized by an...

Genome-wide association study of circulating estradiol, testosterone, and sex hormone-binding globulin in postmenopausal women.

Directory of Open Access Journals (Sweden)

Jennifer Prescott

Full Text Available Genome-wide association studies (GWAS have successfully identified common genetic variants that contribute to breast cancer risk. Discovering additional variants has become difficult, as power to detect variants of weaker effect with present sample sizes is limited. An alternative approach is to look for variants associated with quantitative traits that in turn affect disease risk. As exposure to high circulating estradiol and testosterone, and low sex hormone-binding globulin (SHBG levels is implicated in breast cancer etiology, we conducted GWAS analyses of plasma estradiol, testosterone, and SHBG to identify new susceptibility alleles. Cancer Genetic Markers of Susceptibility (CGEMS data from the Nurses' Health Study (NHS, and Sisters in Breast Cancer Screening data were used to carry out primary meta-analyses among ~1600 postmenopausal women who were not taking postmenopausal hormones at blood draw. We observed a genome-wide significant association between SHBG levels and rs727428 (joint β = -0.126; joint P = 2.09 × 10(-16, downstream of the SHBG gene. No genome-wide significant associations were observed with estradiol or testosterone levels. Among variants that were suggestively associated with estradiol (P<10(-5, several were located at the CYP19A1 gene locus. Overall results were similar in secondary meta-analyses that included ~900 NHS current postmenopausal hormone users. No variant associated with estradiol, testosterone, or SHBG at P<10(-5 was associated with postmenopausal breast cancer risk among CGEMS participants. Our results suggest that the small magnitude of difference in hormone levels associated with common genetic variants is likely insufficient to detectably contribute to breast cancer risk.

Post-heparin plasma lipoprotein lipase, but not hepatic lipase activity, is related to plasma adiponectin in type 2 diabetic patients and healthy subjects

NARCIS (Netherlands)

De Vries, R; Wolffenbuttel, BHR; Sluiter, WJ; Van Tol, A; Dullaart, RPF

2005-01-01

The aim of this study was to determine the relationships of plasma adiponectin with post-heparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activities, and to evaluate whether plasma adiponectin contributes to diabetes-associated dyslipidaemia. Plasma adiponectin, post-heparin plasma

Lipases de látex vegetais: propriedades e aplicações industriais

Directory of Open Access Journals (Sweden)

Paques Fernanda Wiermann

2006-01-01

Full Text Available Biocatalysts have innumerous advantages with respect to classical chemical processes, such as high specificity. Lipases (EC 3.1.1.3 are biocatalysts with large application in synthesis and hydrolysis reactions of triacylglycerols. The search for new sources of lipases has been intensified in the last years due to the high cost of microbial and animal lipases, wich restricts their use on an industrial scale. Lipases obtained from the latex of Carica papaya, Carica pentagona, Euphorbia characias, E. wulfenii, known for their proteolytic properties, are a good alternative source. In this review, we describe the well-known sources of vegetal lipases extracted from the latex and present some of their industrial applications.

Concentrations of testosterone, luteal hormone and prolactin in the serum as well as comparisons of sensitivity between radioimmunoassays and enzyme assays for the detection of acid prostate phosphatase in the presence of carcinomas of the prostate

International Nuclear Information System (INIS)

Vopelius-Feldt, F. von.

1986-01-01

The relationship between carcinomas of the prostate and the plasma levels of testosterone, luteal hormone and prolactin as well as the possible influence of these neoplasms on the testosterone binding capacity and free testosterone index are investigated for various tumour stages and degrees of histological differentiation, in connection with several forms of local therapy as well as a variety of contrasexual methods. The sensitivity of enzyme assays and radioimmunoassays for the detection of acid prostate phosphatase is evaluated within the framework of this study. (MBL) [de

Structural investigations of the regio- and enantioselectivity of lipases

NARCIS (Netherlands)

Lang, Dietmar A.; Dijkstra, Bauke W.

Although lipases are widely applied for the stereospecific resolution of racemic mixtures of esters, the atomic details of the factors that are responsible for their stereospecificity are largely obscure. We determined the X-ray structures of Pseudomonas cepacia lipase in complex with two

Endothelial and lipoprotein lipases in human and mouse placenta

DEFF Research Database (Denmark)

Lindegaard, Marie L S; Olivecrona, Gunilla; Christoffersen, Christina

2005-01-01

Placenta expresses various lipase activities. However, a detailed characterization of the involved genes and proteins is lacking. In this study, we compared the expression of endothelial lipase (EL) and LPL in human term placenta. When placental protein extracts were separated by heparin-Sepharos...

Purification and Characterization of Lipase from Aspergillus flavus ...

African Journals Online (AJOL)

USER

Abstract. Lipase from Aspergillus flavus was purified in a single step purification using MnFeO4 magnetic nano particles to achieve a 20.53- fold purification with specific activity of. 11.29 U/mg and a 59% recovery yield. SDS-PAGE of lipase showed a single pure band with corresponding molecular weight of 35 kDa.

Purification and Characterization of Lipase from Aspergillus flavus ...

African Journals Online (AJOL)

Lipase from Aspergillus flavus was purified in a single step purification using MnFeO4 magnetic nano particles to achieve a 20.53- fold purification with specific activity of 11.29 U/mg and a 59% recovery yield. SDS-PAGE of lipase showed a single pure band with corresponding molecular weight of 35 kDa. The optimal ...

Some important concepts in development of radioimmunoassay (RIA) for hormones, viruses and drugs. [Peptide hormones, non-peptide hormones

Energy Technology Data Exchange (ETDEWEB)

Shah, K B; Mani, R S [Bhabha Atomic Research Centre, Bombay (India). Radiopharmaceuticals Section

1981-01-01

Radioimmunoassay (RIA) procedures for the quantitative measurement of polypeptide and steroid hormones and other substances of medical and biological interest constitute one of the most important and rapidly expanding groups of applications of radioactive tracers in analytical chemistry and the life sciences. The method consists in setting up assays wherein the isotopically tagged substance is allowed to compete with its non-radioactive counterpart for the limited binding sites of a specific antibody. The degree of competitive inhibition of binding of labelled tracer is determined by measuring the radioactivity of the bound or unbound (free) complex, and comparing with the corresponding values for standard solutions of known concentration. This paper outlines the salient features, and specific problems associated with the preparation, purification of immunoreactive labelled tracers, and other suitable RIA reagents, the stability and storage conditions and standardisation of assay procedure. The characteristics of the assay systems have been investigated in detail and regular quality control has been instituted for evaluating various statistical parameters, inter-assay and intra-assay variances, and effective shelf life of the RIA reagents, with specific reference to assays of insulin growth hormones and thyroid and pregnancy hormones.

Lipase applications in oil hydrolysis with a case study on castor oil: a review.

Science.gov (United States)

Goswami, Debajyoti; Basu, Jayanta Kumar; De, Sirshendu

2013-03-01

Lipase (triacylglycerol acylhydrolase) is a unique enzyme which can catalyze various types of reactions such as hydrolysis, esterification, alcoholysis etc. In particular, hydrolysis of vegetable oil with lipase as a catalyst is widely studied. Free lipase, lipase immobilized on suitable support, lipase encapsulated in a reverse micelle and lipase immobilized on a suitable membrane to be used in membrane reactor are the most common ways of employing lipase in oil hydrolysis. Castor oil is a unique vegetable oil as it contains high amounts (90%) of a hydroxy monounsaturated fatty acid named ricinoleic acid. This industrially important acid can be obtained by hydrolysis of castor oil. Different conventional hydrolysis processes have certain disadvantages which can be avoided by a lipase-catalyzed process. The degree of hydrolysis varies widely for different lipases depending on the operating range of process variables such as temperature, pH and enzyme loading. Immobilization of lipase on a suitable support can enhance hydrolysis by suppressing thermal inactivation and estolide formation. The presence of metal ions also affects lipase-catalyzed hydrolysis of castor oil. Even a particular ion has different effects on the activity of different lipases. Hydrophobic organic solvents perform better than hydrophilic solvents during the reaction. Sonication considerably increases hydrolysis in case of lipolase. The effects of additives on the same lipase vary with their types. Nonionic surfactants enhance hydrolysis whereas cationic and anionic surfactants decrease it. A single variable optimization method is used to obtain optimum conditions. In order to eliminate its disadvantages, a statistical optimization method is used in recent studies. Statistical optimization shows that interactions between any two of the following pH, enzyme concentration and buffer concentration become significant in presence of a nonionic surfactant named Span 80.

Covalent immobilization of lipase from Candida rugosa on Eupergit®

Directory of Open Access Journals (Sweden)

Bezbradica Dejan I.

2005-01-01

Full Text Available An approach is presented for the stable covalent immobilization of Upase from Candida rugosa on Eupergit® with a high retention of hydrolytic activity. It comprises covalent bonding via lipase carbohydrate moiety previously modified by periodate oxidation, allowing a reduction in the involvement of the enzyme functional groups that are probably important in the catalytic mechanism. The hydrolytic activities of the lipase immobilized on Eupergif1 by two conventional methods (via oxirane group and via glutaralde-hyde and with periodate method were compared. Results of lipase assays suggest that periodate method is superior for lipase immobilization on Eupergit® among methods applied in this study with respect to both, yield of immobilization and hydrolytic activity of the immobilized enzyme.

Interaction between the triglyceride lipase ATGL and the arf1 activator GBF1

KAUST Repository

Ellong, Emy Njoh

2011-07-18

The Arf1 exchange factor GBF1 (Golgi Brefeldin A resistance factor 1) and its effector COPI are required for delivery of ATGL (adipose triglyceride lipase) to lipid droplets (LDs). Using yeast two hybrid, co-immunoprecipitation in mammalian cells and direct protein binding approaches, we report here that GBF1 and ATGL interact directly and in cells, through multiple contact sites on each protein. The C-terminal region of ATGL interacts with N-terminal domains of GBF1, including the catalytic Sec7 domain, but not with full-length GBF1 or its entire N-terminus. The N-terminal lipase domain of ATGL (called the patatin domain) interacts with two C-terminal domains of GBF1, HDS (Homology downstream of Sec7) 1 and HDS2. These two domains of GBF1 localize to lipid droplets when expressed alone in cells, but not to the Golgi, unlike the full-length GBF1 protein, which localizes to both. We suggest that interaction of GBF1 with ATGL may be involved in the membrane trafficking pathway mediated by GBF1, Arf1 and COPI that contributes to the localization of ATGL to lipid droplets.

Interaction between the triglyceride lipase ATGL and the arf1 activator GBF1

KAUST Repository

Ellong, Emy Njoh; Soni, Krishnakant G.; Bui, Quynh-Trang; Sougrat, Rachid; Golinelli-Cohen, Marie-Pierre; Jackson, Catherine L.

2011-01-01

The Arf1 exchange factor GBF1 (Golgi Brefeldin A resistance factor 1) and its effector COPI are required for delivery of ATGL (adipose triglyceride lipase) to lipid droplets (LDs). Using yeast two hybrid, co-immunoprecipitation in mammalian cells and direct protein binding approaches, we report here that GBF1 and ATGL interact directly and in cells, through multiple contact sites on each protein. The C-terminal region of ATGL interacts with N-terminal domains of GBF1, including the catalytic Sec7 domain, but not with full-length GBF1 or its entire N-terminus. The N-terminal lipase domain of ATGL (called the patatin domain) interacts with two C-terminal domains of GBF1, HDS (Homology downstream of Sec7) 1 and HDS2. These two domains of GBF1 localize to lipid droplets when expressed alone in cells, but not to the Golgi, unlike the full-length GBF1 protein, which localizes to both. We suggest that interaction of GBF1 with ATGL may be involved in the membrane trafficking pathway mediated by GBF1, Arf1 and COPI that contributes to the localization of ATGL to lipid droplets.

Relation of cigarette smoking in males of different ages to sex hormone binding globulin and testosterone

International Nuclear Information System (INIS)

El-Nabarawy, F.S.

2002-01-01

The relationship of cigarette smoking, age, total testosterone free testosterone and sex hormone binding globulin (SHBG) were examined by solid phase radioimmunoassay in 90 randomly chosen healthy males of different ages. The serum levels of these hormones were investigated for smokers compared with non-smokers, of the same ages in 3 groups (adolescent males, middle aged males, and old aged males). Results indicated that cigarette smokers showed increased serum levels of testosterone (60.0% higher, P> 0.05), free testosterone (51.0 higher, P > 0.005) in young adolescent males group, testosterone (27.8% higher, P > 0.001), free testosterone (21.3% higher, P > 0.001) in middle aged males group, and testosterone (21.0% higher, P > 0.001), free testosterone (16.8% higher, P > 0.4) in old ages males group. SHBG was calculated as a mean of free and total testosterone in each group. smokers showed higher mean values of SHBG than non-smokers. Age was positively associated with serum SHBG, it was found that SHBG increased by 17.2% from the youngest (> 18 years) to the oldest age (> 65 years)

Opiate receptor binding in the brain of the seizure sensitive Mongolian gerbil (Meriones unguiculatus).

Science.gov (United States)

Lee, R J; Olsen, R W; Lomax, P; McCabe, R T; Wamsley, J K

1984-12-01

Opiate receptor binding was studied in seizure sensitive (SS) and seizure resistant (SR) strains of the Mongolian gerbil. Cryostat sections of the brain were labeled with [3H]-dihydromorphine, subjected to autoradiography and analysed by microdensitometry. SS gerbils, prior to seizure induction, demonstrated overall greater brain opiate binding when compared to SR animals. Immediately following a seizure, binding in the interpeduncular nucleus fell to levels found in SR animals. The increased opiate binding in the SS (pre-seizure) compared to SR gerbils could reflect a deficit of endogenous ligand which could underlie the seizure diathesis in the gerbil.

Effect of fermentation conditions on lipase production by Candida utilis

Directory of Open Access Journals (Sweden)

SANJA Z. GRBAVCIC

2007-08-01

Full Text Available A wild yeast strain isolated from spoiled soybean oil and identified as Candida utilis initially presented rather low lipase activity (approximately 4 IU dm-3 in submerged culture in a universal yeast medium containing 2 % malt extract. Stu­dies were undertaken to improve the lipase production. The best yields of lipase were obtained with a medium supplemented with caprylic and oleic acids as indu­cers, but higher concentrations of the former (> 0.5 % had a negative effect on the lipase production and cell growth. The type of nitrogen source seemed also to be very important. The highest lipolytic activity of 284 IU dm-3 was achieved after 5 days of fermentation in a medium containing oleic acid and hydrolyzed casein as carbon and nitrogen sources, respectively, and supplemented with Tween 80®. It was shown that optimization of the fermentation conditions can lead to a significant improvement in the lipase production (more than 70-fold higher compared to the initial value obtained in the non-optimized medium.

Characteristics of lipase isolated from coconut (Cocos nucifera linn ...

African Journals Online (AJOL)

GREGO

2007-03-19

Mar 19, 2007 ... Lipase from coconut plant grown under complete nutrient conditions showed ... 35°C and had a broad optimum pH of 7.5 – 8.5. Key words: Lipase .... inhibited by the ex- cess of substrate concentration or change of physio-.

Covalent immobilization of lipases on monodisperse magnetic microspheres modified with PAMAM-dendrimer

Energy Technology Data Exchange (ETDEWEB)

Zhu, Weiwei [Lanzhou University, State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology (China); Zhang, Yimei [Suzhou Research Academy of North China Electric Power University (China); Hou, Chen; Pan, Duo; He, Jianjun; Zhu, Hao, E-mail: zhuhao07@lzu.edu.cn [Lanzhou University, State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology (China)

2016-02-15

This paper reported an immobilization of Candida rugosa lipase (CRL) onto PAMAM-dendrimer-grafted magnetic nanoparticles synthesized by a modified solvothermal reduction method. The dendritic magnetic nanoparticles were amply characterized by several instrumental measurements, and the CRL was covalently anchored on the three generation supports with glutaraldehyde as coupling reagent. The amount of immobilized enzyme was up to 150 mg/g support and the factors related with the enzyme activity were investigated. The immobilization of lipase improved their performance in wider ranges of pH and temperature. The immobilized lipase exhibited excellent thermal stability and reusability in comparison with free enzyme and can be reused 10 cycles with the enzymatic activity remained above 90 %. The properties of lipase improved obviously after being immobilized on the dendritic supports. The inactive immobilized lipase could be regenerated with glutaraldehyde and Cu{sup 2+}, respectively. This synthetic strategy was facile and eco-friendly for applications in lipase immobilization.

Síntese do butirato de n-butila empregando lipase microbiana imobilizada em copolímero de estireno-divinilbenzeno Synthesis of butyl butyrate by microbial lipase immobilized onto styrene-divinylbenzene copolymer

Directory of Open Access Journals (Sweden)

Pedro Carlos de Oliveira

2000-10-01

Full Text Available This work investigates the reaction parameters of an immobilized lipase in the esterification reaction of n-butanol and butyric acid. Microbial lipase from Candida rugosa was immobilized onto styrene-divinylbenzene copolymer (STY-DVB and subsequently introduced in an organic medium containing substrates in appropriate concentrations. Heptane was selected as solvent on the basis of its compatibility with the resin and the enzyme. The influence of molar ratio of acid to alcohol, amount of immobilized lipase and temperature on the butyl butyrate formation was determined. The results were compared with those achieved with free lipase and Lipozyme (commercially immobilized lipase under the same operational conditions.

Influences of apolipoprotein E on soluble and heparin-immobilized hepatic lipase

International Nuclear Information System (INIS)

Landis, B.A.; Rotolo, F.S.; Meyers, W.C.; Clark, A.B.; Quarfordt, S.H.

1987-01-01

The effect of human apolipoprotein E (apoE), either alone or in combination with apoC, on the lipolysis of a radiolabeled triglyceride emulsion was studied with hepatic lipase in solution and immobilized on heparin-Sepharose. The soluble hepatic lipase was inhibited, whereas the heparin-immobilized lipase was stimulated by apoE. This stimulation was attenuated by combining apoE with either apoC-II or C-III. The heparin-immobilized lipase demonstrated much less lipolysis of the zwitterionic phosphatidylcholine-stabilized triglyceride emulsion than did the soluble enzyme. This difference was less when the emulsion was stabilized by a nonionic detergent. apoE inhibited lipase activity when assayed under conditions (0.4 M NaCl) of bound enzyme and unbound substrate. Increasing the emulsion apoE content beyond optimum inhibited lipolysis by the immobilized enzyme. Kinetic analysis of phosphatidylcholine-stabilized triglyceride emulsions revealed a significant decrease in immobilized enzyme K/sub m/ and an increase in V/sub max/ when the emulsion was supplemented with apoE. Distributing the immobilized lipase in clustered aggregates produced more lipolysis than when the same enzyme content was uniformly bound

Secoiridoids from the stem barks of Fraxinus rhynchophylla with pancreatic lipase inhibitory activity.

Science.gov (United States)

Ahn, Jong Hoon; Shin, Eunjin; Liu, Qing; Kim, Seon Beom; Choi, Kyeong-Mi; Yoo, Hwan-Soo; Hwang, Bang Yeon; Lee, Mi Kyeong

2013-01-01

Pancreatic lipase digests dietary fats by hydrolysis, which is a key enzyme for lipid absorption. Therefore, reduction of fat absorption by the inhibition of pancreatic lipase is suggested to be a therapeutic strategy for obesity. From the EtOAc-soluble fraction of the stem barks of Fraxinus rhynchophylla (Oleaceae), four secoiridoids such as ligstroside (1), oleuropein (2), 2"-hydroxyoleuropein (3) and hydroxyframoside B (4) were isolated. The inhibitory activity of these compounds on pancreatic lipase was assessed using porcine pancreatic lipase as an in vitro assay system. Compound 4 showed the strongest inhibition on pancreatic lipase, which followed by compounds 1-3. In addition, compound 4 exerted inhibitory effect on pancreatic lipase in a mixed mechanism of competitive and noncompetitive manner. Taken together, F. rhynchophylla and its constituents might be beneficial to obesity.

Thyroid hormone modulates insulin-like growth factor-I(IGF-I) and IGF-binding protein-3, without mediation by growth hormone, in patients with autoimmune thyroid diseases.

Science.gov (United States)

Inukai, T; Takanashi, K; Takebayashi, K; Fujiwara, Y; Tayama, K; Takemura, Y

1999-10-01

The expression and synthesis of insulin-like growth factor-1 (IGF-I) and IGF-binding protein-3 (IGFBP-3) are regulated by various hormones and nutritional conditions. We evaluated the effects of thyroid hormones on serum levels of IGF-I and IGFBP-3 levels in patients with autoimmune thyroid diseases including 54 patients with Graves' disease and 17 patients with Hashimoto's thyroiditis, and in 32 healthy age-matched control subjects. Patients were subdivided into hyperthyroid, euthyroid and hypothyroid groups that were untreated, or were treated with methylmercaptoimidazole (MMI) or L-thyroxine (L-T4). Serum levels of growth hormone (GH), IGF-I and IGFBP-3 were determined by radioimmunoassay. Serum GH levels did not differ significantly between the hyperthyroid and the age-matched euthyroid patients with Graves' disease. The serum levels of IGF-I and IGFBP-3 showed a significant positive correlation in the patients (R=0.616, Phyperthyroid patients with Graves' disease or in those with Hashimoto's thyroiditis induced by excess L-T4 administration than in control subjects. Patients with hypothyroid Graves' disease induced by the excess administration of MMI showed significantly lower IGFBP-3 levels as compared to those in healthy controls (Phormone modulates the synthesis and/or the secretion of IGF-I and IGFBP-3, and this function is not mediated by GH.

Improvement of lipase production at different stirring speeds and oxygen levels

Directory of Open Access Journals (Sweden)

F.O.M. Alonso

2005-03-01

Full Text Available Lipase production by a Brazilian wild strain of Yarrowia lipolytica at different stirring speeds and air flow rates was studied. The relationship among lipid consumption, cell growth and lipase production by this microorganism is presented. The most pronounced effect of oxygen on lipase production was determined by stirring speed. Maximum lipase activity was detected in the late stationary phase at 200 rpm and an air flow rate of 1-2 dm³/min (0.8-1.7 vvm when the lipid source had been fully consumed. Higher stirring speeds resulted in mechanical and/or oxidative stress, while lower stirring speeds seemed to limit oxygen levels. An increase in the availability of oxygen at higher air flow rates led to faster lipid uptake and anticipation of enzyme release into the culture medium. The highest lipase production was obtained at 200 rpm and 1 dm³/min (0.8 vvm.

Statistical optimization for lipase production from solid waste of vegetable oil industry.

Science.gov (United States)

Sahoo, Rajesh Kumar; Kumar, Mohit; Mohanty, Swati; Sawyer, Matthew; Rahman, Pattanathu K S M; Sukla, Lala Behari; Subudhi, Enketeswara

2018-04-21

The production of biofuel using thermostable bacterial lipase from hot spring bacteria out of low-cost agricultural residue olive oil cake is reported in the present paper. Using a lipase enzyme from Bacillus licheniformis, a 66.5% yield of methyl esters was obtained. Optimum parameters were determined, with maximum production of lipase at a pH of 8.2, temperature 50.8°C, moisture content of 55.7%, and biosurfactant content of 1.693 mg. The contour plots and 3D surface responses depict the significant interaction of pH and moisture content with biosurfactant during lipase production. Chromatographic analysis of the lipase transesterification product was methyl esters, from kitchen waste oil under optimized conditions, generated methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate.

Enzymes used in detergents: Lipases | Hasan | African Journal of ...

African Journals Online (AJOL)

This review describes the applications of microbial lipases in detergents. Enzymes can reduce the environmental load of detergent products as the chemicals used in conventional detergents are reduced; they are biodegradable, non-toxic and leave no harmful residues. Besides lipases, other enzymes are widely used in ...

Optimization of lipase production by Staphylococcus sp. Lp12

African Journals Online (AJOL)

USER

2010-02-08

Feb 8, 2010 ... of the genera Pseudomonas, Bacillus, Staphylococcus,. Achromobacter have been cloned and characterized. Bacterial lipases are mostly inducible enzymes and require some form of oil, fatty acid, fatty acid alcohol or fatty acid ester and surfactants for induction (Immanuel et al., 2008). Lipase biosynthesis ...

Highly Sensitive and High-Throughput Analysis of Plant Hormones Using MS-Probe Modification and Liquid Chromatography–Tandem Mass Spectrometry: An Application for Hormone Profiling in Oryza sativa

Science.gov (United States)

Kojima, Mikiko; Kamada-Nobusada, Tomoe; Komatsu, Hirokazu; Takei, Kentaro; Kuroha, Takeshi; Mizutani, Masaharu; Ashikari, Motoyuki; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto; Suzuki, Koji; Sakakibara, Hitoshi

2009-01-01

We have developed a highly sensitive and high-throughput method for the simultaneous analysis of 43 molecular species of cytokinins, auxins, ABA and gibberellins. This method consists of an automatic liquid handling system for solid phase extraction and ultra-performance liquid chromatography (UPLC) coupled with a tandem quadrupole mass spectrometer (qMS/MS) equipped with an electrospray interface (ESI; UPLC-ESI-qMS/MS). In order to improve the detection limit of negatively charged compounds, such as gibberellins, we chemically derivatized fractions containing auxin, ABA and gibberellins with bromocholine that has a quaternary ammonium functional group. This modification, that we call ‘MS-probe’, makes these hormone derivatives have a positive ion charge and permits all compounds to be measured in the positive ion mode with UPLC-ESI-qMS/MS in a single run. Consequently, quantification limits of gibberellins increased up to 50-fold. Our current method needs 180 plant samples simultaneously. Application of this method to plant hormone profiling enabled us to draw organ distribution maps of hormone species in rice and also to identify interactions among the four major hormones in the rice gibberellin signaling mutants, gid1-3, gid2-1 and slr1. Combining the results of hormone profiling data with transcriptome data in the gibberellin signaling mutants allows us to analyze relationships between changes in gene expression and hormone metabolism. PMID:19369275

alpha-difluoromethylornithine modifies gonadotropin-releasing hormone release and follicle-stimulating hormone secretion in the immature female rat.

Science.gov (United States)

Thyssen, S M; Becú-Villalobos, D; Lacau-Mengido, I M; Libertun, C

1997-06-01

Polyamines play an essential role in tissue growth and differentiation, in body weight increment, in brain organization, and in the molecular mechanisms of hormonal action, intracellular signaling, and cell-to-cell communication. In a previous study, inhibition of their synthesis by alpha-difluoromethylornithine (DFMO), a specific and irreversible inhibitor of ornithine decarboxylase, during development in female rats, was followed by prolonged high follicle-stimulating hormone (FSH) serum level and a delayed puberty onset. Those changes were relatively independent of body mass and did not impair posterior fertility. The present work studies the mechanisms and site of action of polyamine participation in FSH secretion during development. DFMO was injected in female rats between Days 1 and 9 on alternate days. At 10 days of age, hypothalami from control and DFMO rats were perifused in vitro, and basal and potassium-induced gonadotropin-releasing hormone (GnRH) release were measured. The response to membrane depolarization was altered in DFMO hypothalami. Increased GnRH release in response to a low K+ concentration was evidenced. Adenohypophyses of the same treated prepubertal rats were perifused in vitro and the response to GnRH pulses was checked. In DFMO-treated rats, higher FSH release was observed, with no changes in LH or PRL secretion. Finally, pituitary GnRH receptor number in adenohypophyseal membranes from treated and control groups was quantified. A significant reduction in specific binding was evident in hypophyses from DFMO-treated rats when compared with binding in the control group. In summary, DFMO treatment in a critical developmental period in the female rat impacts the immature GnRH neuronal network and immature gonadotropes. A delay in maturation is evidenced by a higher sensitivity to secretagogs in both pituitary glands and hypothalamic explants. These events could explain the prolonged high FSH serum levels and delayed puberty onset seen in

Pituitary resistance to thyroid hormone associated with a base mutation in the hormone-binding domain of the human 3, 5,3[prime]-triiodothyronine receptor-[beta

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Shigekazu; Nakamura, Hirotoshi; Tagami, Tetsuya; Miyoshi, Yohzi; Nogimori, Tsuyoshi; Mitsuma, Terunori; Imura, Hiroo (Kyoto Univ. School of Medicine, Aichi (Japan))

1993-05-01

Point mutations in the human T[sub 3] receptor-[beta] (TR[beta]) gene causing single amino acid substitutions have been identified in several different kindred with generalized resistance to thyroid hormone. Until now, no study has been reported on the TR gene in cases of pituitary resistance (PRTH). In the present study, the authors analyzed the TR[beta] gene in a 30-yr-old Japanese female with PRTH. She exhibited clinical features of hyperthyroidism, elevated serum thyroid hormone levels accompanied by inappropriately increased secretion of TSH, mildly elevated basal metabolic rate, and increased urinary excretion of hydroxyproline. No pituitary tumor was detected. DNA fragments of exons 3-8 of the geonomic TR[beta] gene were generated by the polymerase chain reaction and analyzed by a single stranded conformation polymorphism method. Exon 7 of the patient's TR[beta] gene showed an abnormal band, suggesting the existence of mutation(s). By subcloning and sequencing the DNA, a point mutation was identified in one allele at nucleotide 1297 (C to T), which altered the 333rd amino acid, arginine, to tryptophan. Neither of her apparently normal parents had any mutations of the TR[beta] gene. In vitro translation products of the mutant TR[beta] gene showed remarkably decreased T[sub 3]-binding activity (K[sub a], 2.1 [times] 10[sup 8] M[sup [minus]1]; normal TR[beta] K[sub a], 1.1 [times] 10[sup 10] M[sup [minus]1]). Since the molecular defect detected in a patient with PRTH is similar to that seen in subjects with generalized resistance to thyroid hormone, both types of the syndrome may represent a continuous spectrum of the same etiological defect with variable tissue resistance to thyroid hormone.

Characterization of biotechnologically relevant extracellular lipase produced by Aspergillus terreus NCFT 4269.10

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Bijay Kumar Sethi

2016-03-01

Full Text Available Abstract Enzyme production by Aspergillus terreus NCFT 4269.10 was studied under liquid static surface and solid-state fermentation using mustard oil cake as a substrate. The maximum lipase biosynthesis was observed after incubation at 30 °C for 96 h. Among the domestic oils tested, the maximum lipase biosynthesis was achieved using palm oil. The crude lipase was purified 2.56-fold to electrophoretic homogeneity, with a yield of 8.44%, and the protein had a molecular weight of 46.3 kDa as determined by SDS-PAGE. Enzyme characterization confirmed that the purified lipase was most active at pH 6.0, temperature of 50 °C, and substrate concentration of 1.5%. The enzyme was thermostable at 60 °C for 1 h, and the optimum enzyme–substrate reaction time was 30 min. Sodium dodecyl sulfate and commercial detergents did not significantly affect lipase activity during 30-min incubation at 30 °C. Among the metal ions tested, the maximum lipase activity was attained in the presence of Zn2+, followed by Mg2+ and Fe2+. Lipase activity was not significantly affected in the presence of ethylenediaminetetraacetic acid, sodium lauryl sulfate and Triton X-100. Phenylmethylsulfonyl fluoride (1 mM and the reducing, β-mercaptoethanol significantly inhibited lipase activity. The remarkable stability in the presence of detergents, additives, inhibitors and metal ions makes this lipase unique and a potential candidate for significant biotechnological exploitation.

Production of extracellular lipase by a new strain Staphylococcus ...

African Journals Online (AJOL)

Based on morphological, biochemical and 16S rRNA sequence analysis, the potent isolate was identified as Staphylococcus aureus. The lipase production of the isolate was increased by improving the conditions of production medium. Maximum lipase production (8.11 U/ml) was achieved when 2% punnakka oil was ...

The determination of thyroid hormone autoantibodies and its clinical significance

International Nuclear Information System (INIS)

Zhu Li; Zhao Zhiying; Wang Zhenghua Lian Xiaolan; Guo Zhisheng; Bai Yao; Su Wei

2003-01-01

To study the reasons of falsely high concentrations of serum thyroid hormone and the way of determination of thyroid hormone autoantibodies, the experiments of thyroid hormone autoantibodies binding reaction, dilution testing, calibration curves and their check analysis were performed. Results showed that the combination of the autoantibodies with 125 I-T 3 or 125 I-T 4 was specific, the binding rates were 58.77% and 49.05% respectively and 7-12 times higher than control groups. The radioactive peaks of the autoantibodies and rabbit anti-T 3 or T 4 antibody appeared on the same position in radio electrophoretogram analysis and these antibodies were considered as IgG. The important reasons of falsely high concentrations of serum thyroid hormone are the presence of anti-thyroid hormone antibodies. Determination of thyroid hormone autoantibodies significantly benefits diagnosis and treatment of thyroid disease

Purification and Characterization of a Thermostable Lipase from Geobacillus thermodenitrificans IBRL-nra

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Anuradha Balan

2012-01-01

Full Text Available Thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was purified and characterized. The production of thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was carried out in a shake-flask system at 65°C in cultivation medium containing; glucose 1.0% (w/v; yeast extract 1.25% (w/v; NaCl 0.45% (w/v olive oil 0.1% (v/v with agitation of 200 rpm for 24 hours. The extracted extracellular crude thermostable lipase was purified to homogeneity by using ultrafiltration, Heparin-affinity chromatography, and Sephadex G-100 gel-filtration chromatography by 34 times with a final yield of 9%. The molecular weight of the purified enzyme was estimated to be 30 kDa after SDS-PAGE analysis. The optimal temperature for thermostable lipase was 65°C and it retained its initial activity for 3 hours. Thermostable lipase activity was highest at pH 7.0 and stable for 16 hours at this pH at 65°C. Thermostable lipase showed elevated activity when pretreated with BaCl2, CaCl2, and KCl with 112%, 108%, and 106%, respectively. Lipase hydrolyzed tripalmitin (C16 and olive oil with optimal activity (100% compared to other substrates.

IDENTIFIKASI POTENSI ENZIM LIPASE DAN SELULASE PADA SAMPAH KULIT BUAH HASIL FERMENTASI

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La Ode Sumarlin

2013-12-01

Full Text Available Fermentation is one of bioconversion to produce profitable anaerobic microbes and to produce various enzymes. Lipases and cellulases are widely used enzymes so far. Cellulases play an important role in bioconversion of organic waste cellulosic materials to glucose, single cell proteins, animal feed, and ethanol. Lipases can also degrade fatty ester bond. Therefore, both enzymes are potential to be used in industry as well as in households. Fermentation of fruit peel waste is an attempt to produce cellulase and lipase that can be carried out in a simple way. Cellulase as says was performed using DNS (3.5-dinitrosalicylic acid and acid-base titration for analysis of lipase using cooking oil as the substrate. The results showed that the highest cellulase activity was obtained from watermelon rind mixed with citrus fruit peel of 0.036 U/mL, and mixed of banana peel and citrus fruit, which was 0.035 U/mL. The optimum lipase activity was at 30 oC, pH 7, and reaction time of 60 minutes. The highest lipase activity (1.36 U/mL was obtained from mixture of watermelon and orange rind. Thus, the fruit peel waste is potential to produce cellulase and lipase by fermentation .

Adrenal and liver in normal and cld/cld mice synthesize and secrete hepatic lipase, but the lipase is inactive in cld/cld mice.

Science.gov (United States)

Schultz, C J; Blanchette-Mackie, E J; Scow, R O

2000-02-01

Combined lipase deficiency (cld) is a recessive mutation in mice that causes a severe lack of lipoprotein lipase (LPL) and hepatic lipase (HL) activities, hyperlipemia, and death within 3 days after birth. Earlier studies showed that inactive LPL and HL were synthesized by cld/cld tissues and that LPL synthesized by cld/cld brown adipocytes was retained in their ER. We report here a study of HL in liver, adrenal, and plasma of normal newborn and cld/cld mice. Immunofluorescence studies showed HL was present in extracellular space, but not in cells, in liver and adrenal of both normal and cld/cld mice. When protein secretion was blocked with monensin, HL was retained intracellularly in liver cell cultures and in incubated adrenal tissues of both groups of mice. These findings demonstrated that HL was synthesized and secreted by liver and adrenal cells in normal newborn and cld/cld mice. HL activities in liver, adrenal, and plasma in cld/cld mice were very low, cld/cld cells was inactive. Livers of both normal newborn and cld/cld mice synthesized LPL, but the level of LPL activity in cld/cld liver was very low, cld/cld mice, indicating that LPL was synthesized but not secreted by cld/cld liver cells. Immunofluorescent LPL was not found in normal newborn liver cells unless the cells were treated with monensin, thus demonstrating that normal liver cells synthesized and secreted LPL. Livers of both groups of mice contained an unidentified alkaline lipase activity which accounted for 34-54% of alkaline lipase activity in normal and 65% of that in cld/cld livers. Our findings indicate that liver and adrenal cells synthesized and secreted HL in both normal newborn and cld/cld mice, but the lipase was inactive in cld/cld mice. That cld/cld liver cells secreted inactive HL while retaining inactive LPL indicates that these closely related lipases were processed differently.

Candesartan decreases the sympatho-adrenal and hormonal response to isolation stress

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Ines Armando

2001-03-01

Full Text Available A change from group housing to isolation in unfamiliar metabolic cages represents, for rodents, a significant emotional stress. We studied the effect of candesartan, a peripheral and central angiotensin II AT1-receptor antagonist, on the hormonal and sympathetic response to acute isolation. We pretreated rats with 1 mg/kg/day candesartan for 13 days via subcutaneously implanted osmotic minipumps, followed by 24-hour isolation in individual metabolic cages. We measured brain, pituitary and adrenal angiotensin II (Ang II receptor binding by quantitative autoradiography and adrenal hormones and catecholamines by RIA and HPLC. Isolation increased adrenal catecholamines, aldosterone and corticosterone, AT1-receptor binding in the zona glomerulosa and AT2-receptor binding in the adrenal medulla. Candesartan pretreatment decreased adrenal catecholamines, aldosterone and corticosterone, AT1-receptor binding in adrenal zona glomerulosa and medulla, pituitary gland and the hypothalamic paraventricular nucleus, and AT2-receptor binding in adrenal medulla, but increased AT2-receptor binding in zona glomerulosa. We conclude that peripheral and central AT1-receptor blockade with candesartan decreases the sympatho-adrenal and hormonal response to acute stress. Our results indicate that Ang II is an important stress hormone and suggest that blockade of the physiologically active AT 1-receptors could influence stress-related disorders.

Structural insights into methanol-stable variants of lipase T6 from Geobacillus stearothermophilus.

Science.gov (United States)

Dror, Adi; Kanteev, Margarita; Kagan, Irit; Gihaz, Shalev; Shahar, Anat; Fishman, Ayelet

2015-11-01

Enzymatic production of biodiesel by transesterification of triglycerides and alcohol, catalyzed by lipases, offers an environmentally friendly and efficient alternative to the chemically catalyzed process while using low-grade feedstocks. Methanol is utilized frequently as the alcohol in the reaction due to its reactivity and low cost. However, one of the major drawbacks of the enzymatic system is the presence of high methanol concentrations which leads to methanol-induced unfolding and inactivation of the biocatalyst. Therefore, a methanol-stable lipase is of great interest for the biodiesel industry. In this study, protein engineering was applied to substitute charged surface residues with hydrophobic ones to enhance the stability in methanol of a lipase from Geobacillus stearothermophilus T6. We identified a methanol-stable variant, R374W, and combined it with a variant found previously, H86Y/A269T. The triple mutant, H86Y/A269T/R374W, had a half-life value at 70 % methanol of 324 min which reflects an 87-fold enhanced stability compared to the wild type together with elevated thermostability in buffer and in 50 % methanol. This variant also exhibited an improved biodiesel yield from waste chicken oil compared to commercial Lipolase 100L® and Novozyme® CALB. Crystal structures of the wild type and the methanol-stable variants provided insights regarding structure-stability correlations. The most prominent features were the extensive formation of new hydrogen bonds between surface residues directly or mediated by structural water molecules and the stabilization of Zn and Ca binding sites. Mutation sites were also characterized by lower B-factor values calculated from the X-ray structures indicating improved rigidity.

Strategies to Characterize Fungal Lipases for Applications in Medicine and Dairy Industry

Science.gov (United States)

Gopinath, Subash C. B.; Anbu, Periasamy; Lakshmipriya, Thangavel; Hilda, Azariah

2013-01-01

Lipases are water-soluble enzymes that act on insoluble substrates and catalyze the hydrolysis of long-chain triglycerides. Lipases play a vital role in the food, detergent, chemical, and pharmaceutical industries. In the past, fungal lipases gained significant attention in the industries due to their substrate specificity and stability under varied chemical and physical conditions. Fungal enzymes are extracellular in nature, and they can be extracted easily, which significantly reduces the cost and makes this source preferable over bacteria. Soil contaminated with spillage from the products of oil and dairy harbors fungal species, which have the potential to secrete lipases to degrade fats and oils. Herein, the strategies involved in the characterization of fungal lipases, capable of degrading fatty substances, are narrated with a focus on further applications. PMID:23865040

MALDI imaging of enzymatic degradation of glycerides by lipase on textile surface

DEFF Research Database (Denmark)

Hall-Andersen, Jonatan; Kaasgaard, Svend G; Janfelt, Christian

2018-01-01

Most modern laundry detergents contain enzymes such as proteases, amylases, and lipases for more efficient removal of stains containing proteins, carbohydrates, and lipids during wash at low temperature. The function of the lipases is to hydrolyse the hydrophobic triglycerides from fats and oils...... stain and simulating washing cycles using well-defined detergents with lipase concentrations ranging between 0 and 0.5ppm. After washing, the textile swatches as well as cryo-sections of the swatches were imaged using MALDI imaging in positive ion mode at pixel sizes of 15-75μm. Similar samples were...... an inhomogeneous presence of diglycerides after lipase treatment both in planar images of the textile surface as well as in cross-sections suggesting a non-uniform enzyme effect or extraction of the lipase reaction products from the textile....

Anaerobic biodegradability of dairy wastewater pretreated with porcine pancreas lipase

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Adriano Aguiar Mendes

2010-12-01

Full Text Available Lipids-rich wastewater was partial hydrolyzed with porcine pancreas lipase and the efficiency of the enzymatic pretreatment was verified by the comparative biodegradability tests (crude and treated wastewater. Alternatively, simultaneous run was carried out in which hydrolysis and digestion was performed in the same reactor. Wastewater from dairy industries and low cost lipase preparation at two concentrations (0.05 and 0.5% w.v-1 were used. All the samples pretreated with enzyme showed a positive effect on organic matter removal (Chemical Oxygen Demand-COD and formation of methane. The best results were obtained when hydrolysis and biodegradation were performed simultaneously, attaining high COD and color removal independent of the lipase concentration. The enzymatic treatment considerably improved the anaerobic operational conditions and the effluent quality (lower content of suspended solids and less turbidity. Thus, the use of enzymes such as lipase seemed to be a very promising alternative for treating the wastewaters having high fat and grease contents, such as those from the dairy industry.O presente trabalho teve como objetivo o pré-tratamento de efluente da indústria de laticínios na hidrólise de lipídeos, empregando lipase de fonte de células animais de baixo custo disponível comercialmente (pâncreas de porco na formação de gás metano por biodegradabilidade anaeróbia empregando diferentes concentrações de lipase (0,05 e 0,5 % w.v-1. A utilização de lipase no pré-tratamento do efluente acelerou a hidrólise de lipídeos e, conseqüentemente, auxiliou o tratamento biológico resultando na redução da matéria orgânica em termos de Demanda Química de Oxigênio (DQO, cor e sólidos em suspensão como lipídeos. Os melhores resultados em termos de remoção de DQO e cor foram obtidos quando a hidrólise e biodigestão foram realizadas simultaneamente, independente da concentração de lipase empregada. Estes resultados

Methodological Aspects and Relevance of the Study of Vegetable Oil, Fat and Lipoprotein Oxidation Using Pancreatic Lipase and Arylesterase

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Meritxell Nus

2006-01-01

Full Text Available Fats and oils as major dietary components are involved in the development of chronic diseases. In this paper the physiological relevance and some methodological aspects related to the determination of two enzymes enrolled in metabolism of fat – pancreatic lipase and arylesterase – are discussed. Pancreatic lipase has been extensively used to study the triacylglycerol fatty acid composition and the in vitro digestion of oils and fats. The action of this enzyme may be coupled to analytical methods as GC, HPLC, HPSEC, TLC- -FID, etc. as a useful tool for understanding the composition and digestion of thermal oxidized oils. Pancreatic lipase hydrolysis occurs in the water/oil interface, and it presents a behaviour that seems to be Michaelian, in which the apparent Km and the apparent Vmax of the enzymatic process depend more on the type of oil tested than on the degree of alteration. The kinetic behaviour of pancreatic lipase towards thermally oxidized oils also depends on the presence of natural tensioactive compounds present in the oil and surfactants formed during the frying. Arylesterase is an HDL binding enzyme that inhibits LDL oxidation. Low serum concentration of this enzyme has been related to increased cardiovascular disease risk. In this paper the most widely used methods for the determination of arylesterase activity are commented on. The importance of intrinsic factors (e.g. substrates, cofactors participating in the enzyme reaction is also discussed. Moreover, several suggestions about further researches on the influence of extrinsic factors (e.g. diet, oxidative stress upon the enzyme activity are proposed.

Radioreceptor assays: plasma membrane receptors and assays for polypeptide and glycoprotein hormones

International Nuclear Information System (INIS)

Schulster, D.

1977-01-01

Receptors for peptide, protein and glycoprotein hormones, and the catecholamines are located on the plasma membranes of their target cells. Preparations of the receptors may be used as specific, high-affinity binding agents for these hormones in assay methodology akin to that for radioimmunoassay. A particular advantage of the radioreceptor assay is that it has a specificity directed towards the biologically active region of the hormone, rather than to some immunologically active region that may have little (or no) involvement in the expression of hormonal activity. Methods for hormone receptor preparation vary greatly, and range from the use of intact cells (as the source of hormone receptor) to the use of purified or solubilized membrane receptors. Receptors isolated from plasma membranes have proved to be of variable stability, and may be damaged during preparation and/or storage. Moreover, since they are present in relatively low concentration in the cell, their preparation in sufficient quantity for use in a radioreceptor assay may present technical problems. In general, there is good correlation between radioreceptor assays and in-vitro bioassays; differences between results from radioreceptor assays and radioimmunoassays are similar to those noted between in-vitro bioassays and radioimmunoassays. The sensitivity of the method is such that normal plasma concentrations of various hormones have been assayed by this technique. (author)

Lipase Activity in Fermented Oil Seeds of Africa Locust Bean ...

African Journals Online (AJOL)

acer

was determined. The peak lipase activity for fermented Africa locust bean, Castor seed, and African ..... Lipase by Penicillium restrictum in solid state ... sp. Rev. Microbiol. 28(2): 90-95. Martinek, G.H. (1969). Microbiology and amino acid ...

Enzymatic production of alkyl esters through alcoholysis: A critical evaluation of lipases and alcohols

DEFF Research Database (Denmark)

Li, Deng; Xu, Xuebing; Gudmundur G, Haraldsson

2005-01-01

This paper focuses on a detailed evaluation of commercially available immobilized lipases and simple monohydric alcohols for the production of alkyl esters from sunflower oil by enzymatic alcoholysis. Six lipases were tested with seven alcohols, including straight and branched-chain primary...... in an increased degree of conversion for all lipases except Novozym 435. The secondary alcohol 2-propanol significantly reduced the alcoholysis reaction with all lipases; however, the branch-chain isobutanol was more advantageous than linear 1-butanol for Novozym 435, Lipozyme RM IM, and Lipase PS-C. Many...

Lipase-nanoporous gold biocomposite modified electrode for reliable detection of triglycerides.

Science.gov (United States)

Wu, Chao; Liu, Xueying; Li, Yufei; Du, Xiaoyu; Wang, Xia; Xu, Ping

2014-03-15

For triglycerides biosensor design, protein immobilization is necessary to create the interface between the enzyme and the electrode. In this study, a glassy carbon electrode (GCE) was modified with lipase-nanoporous gold (NPG) biocomposite (denoted as lipase/NPG/GCE). Due to highly conductive, porous, and biocompatible three-dimensional structure, NPG is suitable for enzyme immobilization. In cyclic voltammetry experiments, the lipase/NPG/GCE bioelectrode displayed surface-confined reaction in a phosphate buffer solution. Linear responses were obtained for tributyrin concentrations ranging from 50 to 250 mg dl(-1) and olive oil concentrations ranging from 10 to 200 mg dl(-1). The value of apparent Michaelis-Menten constant for tributyrin was 10.67 mg dl(-1) and the detection limit was 2.68 mg dl(-1). Further, the lipase/NPG/GCE bioelectrode had strong anti-interference ability against urea, glucose, cholesterol, and uric acid as well as a long shelf-life. For the detection of triglycerides in human serum, the values given by the lipase/NPG/GCE bioelectrode were in good agreement with those of an automatic biochemical analyzer. These properties along with a long self-life make the lipase/NPG/GCE bioelectrode an excellent choice for the construction of triglycerides biosensor. © 2013 Elsevier B.V. All rights reserved.

Relação lipase/amilase nas pancreatites agudas de causa biliar e nas pancreatites agudas/crônicas agudizadas de causa alcoólica Lipase/amylase ratio in biliary acute pancreatitis and alcoholic acute/acutized chronic pancreatitis

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Ricardo Custódio Pacheco

2007-03-01

with alcoholic acute pancreatitis/acutized chronic pancreatitis (group I and 29 patients, 8 male and 21 female (mean age: 43.6 ± 19.9 years, with biliary acute pancreatitis (group II were evaluated. Serum lipase and amylase levels were measured in patients with symptoms for no more than 48 hours. The lipase/amylase ratio was calculated based on serum lipase and amylase levels and expressed as multiples of their respective superior reference values. RESULTS: Mean levels of serum lipase (4,814 ± 3,670 U/L and amylase (1,282 ± 777 U/L in patients of group I were comparable to group II (2,697 ± 2,391 and 1,878 ± 1,319 U/L, respectively, but the mean lipase/amylase ratio was significantly higher in group I (4.4 ± 3.6 than in group II (2.2 ± 2.2. Lipase/amylase ratio >3 occurred at significantly higher proportions in patients of group I (66.7% than of group II (24.1%, differentiating the two groups with sensitivity of 67% and specificity of 76%. CONCLUSIONS: 1 Amylase and lipase serum levels did not differ in the two groups evaluated; 2 the lipase/amylase ratio >3 was more often seen in alcoholic acute pancreatitis/acutized chronic pancreatitis than biliary acute pancreatitis, and it may be useful in differentiating these two causes of pancreatitis.

Biodiesel production by transesterification using immobilized lipase.

Science.gov (United States)

Narwal, Sunil Kumar; Gupta, Reena

2013-04-01

Biodiesel can be produced by transesterification of vegetable or waste oil catalysed by lipases. Biodiesel is an alternative energy source to conventional fuel. It combines environmental friendliness with biodegradability, low toxicity and renewability. Biodiesel transesterification reactions can be broadly classified into two categories: chemical and enzymatic. The production of biodiesel using the enzymatic route eliminates the reactions catalysed under acid or alkali conditions by yielding product of very high purity. The modification of lipases can improve their stability, activity and tolerance to alcohol. The cost of lipases and the relatively slower reaction rate remain the major obstacles for enzymatic production of biodiesel. However, this problem can be solved by immobilizing the enzyme on a suitable matrix or support, which increases the chances of re-usability. The main factors affecting biodiesel production are composition of fatty acids, catalyst, solvents, molar ratio of alcohol and oil, temperature, water content, type of alcohol and reactor configuration. Optimization of these parameters is necessary to reduce the cost of biodiesel production.

Recombinant Lipases and Phospholipases and Their Use as Biocatalysts for Industrial Applications

OpenAIRE

Borrelli, Grazia M.; Trono, Daniela

2015-01-01

Lipases and phospholipases are interfacial enzymes that hydrolyze hydrophobic ester linkages of triacylglycerols and phospholipids, respectively. In addition to their role as esterases, these enzymes catalyze a plethora of other reactions; indeed, lipases also catalyze esterification, transesterification and interesterification reactions, and phospholipases also show acyltransferase, transacylase and transphosphatidylation activities. Thus, lipases and phospholipases represent versatile bioc...

Enzymatic interesterification of palm stearin and coconut oil by a dual lipase system

DEFF Research Database (Denmark)

Ibrahim, Nuzul Amri Bin; Guo, Zheng; Xu, Xuebing

2008-01-01

greater than 100% over the theoretical value when the reaction proceeds for 2 h. The co-immobilization action of the carrier of the immobilized lipases towards the free lipase was proposed as being one of the reasons leading to the synergistic effect and this has been experimentally verified by a reaction......Enzymatic interesterification of palm stearin with coconut oil was conducted by applying a dual lipase system in comparison with individual lipase-catalyzed reactions. The results indicated that a synergistic effect occurred for many lipase combinations, but largely depending on the lipase species...... mixed and their ratios. The combination of Lipozyme TL IM and RM IM was found to generate a positive synergistic action at all test mixing ratios. Only equivalent amount mixtures of Lipozyme TL IM with Novozym 435 or Lipozyme RM IM with Novozym 435 produced a significant synergistic effect as well...

H-2RIIBP, a member of the nuclear hormone receptor superfamily that binds to both the regulatory element of major histocompatibility class I genes and the estrogen response element.

Science.gov (United States)

Hamada, K; Gleason, S L; Levi, B Z; Hirschfeld, S; Appella, E; Ozato, K

1989-11-01

Transcription of major histocompatibility complex (MHC) class I genes is regulated by the conserved MHC class I regulatory element (CRE). The CRE has two factor-binding sites, region I and region II, both of which elicit enhancer function. By screening a mouse lambda gt 11 library with the CRE as a probe, we isolated a cDNA clone that encodes a protein capable of binding to region II of the CRE. This protein, H-2RIIBP (H-2 region II binding protein), bound to the native region II sequence, but not to other MHC cis-acting sequences or to mutant region II sequences, similar to the naturally occurring region II factor in mouse cells. The deduced amino acid sequence of H-2RIIBP revealed two putative zinc fingers homologous to the DNA-binding domain of steroid/thyroid hormone receptors. Although sequence similarity in other regions was minimal, H-2RIIBP has apparent modular domains characteristic of the nuclear hormone receptors. Further analyses showed that both H-2RIIBP and the natural region II factor bind to the estrogen response element (ERE) of the vitellogenin A2 gene. The ERE is composed of a palindrome, and half of this palindrome resembles the region II binding site of the MHC CRE. These results indicate that H-2RIIBP (i) is a member of the superfamily of nuclear hormone receptors and (ii) may regulate not only MHC class I genes but also genes containing the ERE and related sequences. Sequences homologous to the H-2RIIBP gene are widely conserved in the animal kingdom. H-2RIIBP mRNA is expressed in many mouse tissues, in agreement with the distribution of the natural region II factor.

Toward Improved Force-Field Accuracy through Sensitivity Analysis of Host-Guest Binding Thermodynamics

Science.gov (United States)

Yin, Jian; Fenley, Andrew T.; Henriksen, Niel M.; Gilson, Michael K.

2015-01-01

Improving the capability of atomistic computer models to predict the thermodynamics of noncovalent binding is critical for successful structure-based drug design, and the accuracy of such calculations remains limited by non-optimal force field parameters. Ideally, one would incorporate protein-ligand affinity data into force field parametrization, but this would be inefficient and costly. We now demonstrate that sensitivity analysis can be used to efficiently tune Lennard-Jones parameters of aqueous host-guest systems for increasingly accurate calculations of binding enthalpy. These results highlight the promise of a comprehensive use of calorimetric host-guest binding data, along with existing validation data sets, to improve force field parameters for the simulation of noncovalent binding, with the ultimate goal of making protein-ligand modeling more accurate and hence speeding drug discovery. PMID:26181208

Developmental Thyroid Hormone (TH) Disruption: In Search of Sensitive Bioindicators of Altered TH-Dependent Signaling in Brain

Science.gov (United States)

Thyroid hormones (TH) are essential for brain development, yet clear indicators of disruption at low levels of TH insufficiency have yet to be identified. Brain TH is difficult to measure, but TH-responsive genes can serve as sensitive indicators of TH action in brain. A large nu...

Developmental Thyroid Hormone (TH) Disruption: In Search of Sensitive Bioindicators of Altered TH-Dependent Signaling in Brain###

Science.gov (United States)

Thyroid hormones (TH) are essential for brain development, yet clear indicators of disruption at low levels of TH insufficiency have yet to be identified. Brain TH is difficult to measure, but TH-responsive genes can serve as sensitive indicators of TH action in brain. A large nu...

Association between sex hormone-binding globulin (SHBG and metabolic syndrome among men

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Emmanuela Quental Callou de Sá

Full Text Available CONTEXT AND OBJECTIVE: Metabolic syndrome consists of a set of factors that imply increased risk of cardiovascular diseases. The objective here was to evaluate the association between sex hormone-binding globulin (SHBG, sex hormones and metabolic syndrome among men. DESIGN AND SETTING: Retrospective analysis on data from the study "Endogenous oestradiol but not testosterone is related to coronary artery disease in men", conducted in a hospital in São Paulo. METHODS: Men (aged 40-70 who underwent coronary angiography were selected. The age, weight, height, waist circumference, body mass index and prevalence of dyslipidemia, hypertension and diabetes of each patient were registered. Metabolic syndrome was defined in accordance with the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (NCEP-ATPIII. Serum samples were collected to assess the levels of glucose, total cholesterol, HDL-cholesterol (high density lipoprotein, triglycerides, albumin, SHBG, estradiol and total testosterone (TT. The levels of LDL-cholesterol (low density lipoprotein were calculated using Friedewald's formula and free testosterone (FT and bioavailable testosterone (BT using Vermeulen's formula. RESULTS: 141 patients were enrolled in the study. The prevalence of metabolic syndrome was significantly higher in the first SHBG tercile than in the second and third terciles. A statistically significant positive association between the SHBG and TT values was observed, but no such association was seen between SHBG, BT and FT. CONCLUSION: Low serum levels of SHBG are associated with higher prevalence of metabolic syndrome among male patients, but further studies are required to confirm this association.

A model for hormonal control of the menstrual cycle: structural consistency but sensitivity with regard to data.

Science.gov (United States)

Selgrade, J F; Harris, L A; Pasteur, R D

2009-10-21

This study presents a 13-dimensional system of delayed differential equations which predicts serum concentrations of five hormones important for regulation of the menstrual cycle. Parameters for the system are fit to two different data sets for normally cycling women. For these best fit parameter sets, model simulations agree well with the two different data sets but one model also has an abnormal stable periodic solution, which may represent polycystic ovarian syndrome. This abnormal cycle occurs for the model in which the normal cycle has estradiol levels at the high end of the normal range. Differences in model behavior are explained by studying hysteresis curves in bifurcation diagrams with respect to sensitive model parameters. For instance, one sensitive parameter is indicative of the estradiol concentration that promotes pituitary synthesis of a large amount of luteinizing hormone, which is required for ovulation. Also, it is observed that models with greater early follicular growth rates may have a greater risk of cycling abnormally.

Effect of atrial natriuretic peptide on lipolysis in the mouse heart

DEFF Research Database (Denmark)

Bartels, Emil Daniel; Bisgaard, Line Stattau; Christoffersen, Christina

2014-01-01

-A (NPR-A), leading to cGMP-dependent phosphorylation of hormone-sensitive lipase. Cardiac myocytes express NPR-A and hormone-sensitive lipase. In the present study, we investigated whether ANP affects triglyceride stores in the heart. Subcutaneously implanted osmotic minipumps were used to administer ANP...... (125 or 500 ng/kg/min) or saline to obese leptin-deficient (ob/ob) mice or lean control mice (ob/+) for a week. ANP (500 ng/kg/min) reduced blood pressure but did not affect the cardiac triglyceride stores or mRNA expression of NPR-A and NPR-C. Also, deficiency of NPR-A did not affect the cardiac...... triglyceride content. Finally, addition of ANP to the culture medium (10−7 mol/l) increased cellular cGMP content (P=0.009) but did not affect triglyceride stores in HL-1 cardiac myocyte cultures. Hence, ANP does not affect triglyceride stores in the murine heart....

Binding of [125I]iodipine to parathyroid cell membranes: Evidence of a dihydropyridine-sensitive calcium channel

International Nuclear Information System (INIS)

Jones, J.I.; Fitzpatrick, L.A.

1990-01-01

The parathyroid cell is unusual, in that an increase in extracellular calcium concentrations inhibits PTH release. Calcium channels are glycoproteins that span cell membranes and allow entry of extracellular calcium into cells. We have demonstrated that the calcium channel agonist (+)202-791, which opens calcium channels, inhibits PTH release and that the antagonist (-)202-791, which closes calcium channels, stimulates PTH release. To identify the calcium channels responsible for these effects, we used a radioligand that specifically binds to calcium channels. Bovine parathyroid cell membranes were prepared and incubated under reduced lighting with [125I] iodipine (SA, 2000 Ci/mmol), which recognizes 1,4-dihydropyridine-sensitive calcium channels. Bound ligand was separated from free ligand by rapid filtration through Whatman GF/B filters. Nonspecific binding was measured by the inclusion of nifedipine at 10 microM. Specific binding represented approximately 40% of the total binding. The optimal temperature for [125I] iodipine binding was 4 C, and binding reached equilibrium by 30 min. The equilibrium dissociation constant (Kd) was approximately 550 pM, and the maximum number of binding sites was 780 fmol/mg protein. Both the calcium channel agonist (+)202-791 and antagonist (-)202-791 competitively inhibited [125I] iodipine binding, with 50% inhibition concentrations of 20 and 300 nM, respectively. These data indicate the presence of dihydropyridine-sensitive calcium channels on parathyroid cell membranes

Lipase biocatalysis for useful biodegradable products

Energy Technology Data Exchange (ETDEWEB)

Linko, Y Y; Wang, Zhuo Lin; Uosukainen, E; Seppaelae, J [Helsinki Univ. of Technology, Espoo (Finland); Laemsae, M [Raisio Group Oil Milling Industry, Raisio (Finland)

1997-12-31

It was shown that lipases can be used as biocatalysts in the production of useful biodegradable compounds such as 1-butyl oleate by direct esterification of butanol and oleic acid to decrease viscosity of biodiesel in winter use. By enzymic transesterification, a mixture of 2-ethyl-1-hexyl esters from rapeseed oil fatty acids can be obtained in good yields for use as a solvent, and of trimethylolpropane esters for use as a lubricant. Finally, it was demonstrated that polyesters with a mass average molar mass in excess of 75,000 g mol{sup -}1 can be obtained by esterification or transesterification by using lipase as biocatalyst. (author) (3 refs.)

Lipase biocatalysis for useful biodegradable products

Energy Technology Data Exchange (ETDEWEB)

Linko, Y.Y.; Wang, Zhuo Lin; Uosukainen, E.; Seppaelae, J. [Helsinki Univ. of Technology, Espoo (Finland); Laemsae, M. [Raisio Group Oil Milling Industry, Raisio (Finland)

1996-12-31

It was shown that lipases can be used as biocatalysts in the production of useful biodegradable compounds such as 1-butyl oleate by direct esterification of butanol and oleic acid to decrease viscosity of biodiesel in winter use. By enzymic transesterification, a mixture of 2-ethyl-1-hexyl esters from rapeseed oil fatty acids can be obtained in good yields for use as a solvent, and of trimethylolpropane esters for use as a lubricant. Finally, it was demonstrated that polyesters with a mass average molar mass in excess of 75,000 g mol{sup -}1 can be obtained by esterification or transesterification by using lipase as biocatalyst. (author) (3 refs.)

Structural basis of the chiral selectivity of Pseudomonas cepacia lipase

NARCIS (Netherlands)

Lang, Dietmar A.; Mannesse, Maurice L.M.; Haas, Gerard H. de; Verheij, Hubertus M.; Dijkstra, Bauke W.

1998-01-01

To investigate the enantioselectivity of Pseudomonas cepacia lipase, inhibition studies were performed with S(c)-and R(c)-(R(p),S(p))-1,2-dialkylcarbamoylglycero-3-O-p-nitrophenyl alkylphosphonates of different alkyl chain lengths. P. cepacia lipase was most rapidly inactivated by

Combined sodium ion sensitivity in agonist binding and internalization of vasopressin V1b receptors.

Science.gov (United States)

Koshimizu, Taka-Aki; Kashiwazaki, Aki; Taniguchi, Junichi

2016-05-03

Reducing Na(+) in the extracellular environment may lead to two beneficial effects for increasing agonist binding to cell surface G-protein coupled receptors (GPCRs): reduction of Na(+)-mediated binding block and reduce of receptor internalization. However, such combined effects have not been explored. We used Chinese Hamster Ovary cells expressing vasopressin V1b receptors as a model to explore Na(+) sensitivity in agonist binding and receptor internalization. Under basal conditions, a large fraction of V1b receptors is located intracellularly, and a small fraction is in the plasma membrane. Decreases in external Na(+) increased cell surface [(3)H]AVP binding and decreased receptor internalization. Substitution of Na(+) by Cs(+) or NH4(+) inhibited agonist binding. To suppress receptor internalization, the concentration of NaCl, but not of CsCl, had to be less than 50 mM, due to the high sensitivity of the internalization machinery to Na(+) over Cs(+). Iso-osmotic supplementation of glucose or NH4Cl maintained internalization of the V1b receptor, even in a low-NaCl environment. Moreover, iodide ions, which acted as a counter anion, inhibited V1b agonist binding. In summary, we found external ionic conditions that could increase the presence of high-affinity state receptors at the cell surface with minimum internalization during agonist stimulations.

Structure and Function of Lipase

DEFF Research Database (Denmark)

Skjold-Jørgensen, Jakob

.e. the waterlipidinterface. For Thermomyces lanuginosus lipase (TlL) and related lipases, activation of the enzymeinvolves a rearrangement of a structural domain, called the “lid”, which covers the active site inhomogenous aqueous solution. At the water-lipid interface, the lid is displaced from the active site andmoves...... the water-lipid interface, structural movements occurring during activation have been difficult to probeexperimentally. In this work, novel variants of TlL were constructed based on rational design with amutated lid-region in order to elucidate the impact of the lid-residue composition and characteristics...... onthe activation mechanism. From characterization studies of these variants we have shown (Paper I) thatthe lid-region plays a crucial role in governing interfacial activation and enzymatic activity. Specifically,using a combination of spectroscopic and enzymatic activity-based methods we have...

The genotypic diversity and lipase production of some thermophilic bacilli from different genera

Directory of Open Access Journals (Sweden)

Melih Koc

2015-12-01

Full Text Available Abstract Thermophilic 32 isolates and 20 reference bacilli were subjected to Rep-PCR and ITS-PCR fingerprinting for determination of their genotypic diversity, before screening lipase activities. By these methods, all the isolates and references could easily be differentiated up to subspecies level from each other. In screening assay, 11 isolates and 7 references were found to be lipase producing. Their extracellular lipase activities were measured quantitatively by incubating in both tributyrin and olive oil broths at 60 °C and pH 7.0. During the 24, 48 and 72-h period of incubation, the changes in the lipase activities, culture absorbance, wet weight of biomass and pH were all measured. The activity was determined by using pNPB in 50 mM phosphate buffer at pH 7.0 at 60 °C. The lipase production of the isolates in olive oil broths varied between 0.008 and 0.052, whereas these values were found to be 0.002-0.019 (U/mL in the case of tyributyrin. For comparison, an index was established by dividing the lipase activities to cell biomass (U/mg. The maximum thermostable lipase production was achieved by the isolates F84a, F84b, and G. thermodenitrificans DSM 465T (0.009, 0.008 and 0.008 U/mg within olive oil broth, whereas G. stearothermophilus A113 displayed the highest lipase activity than its type strain in tyributyrin. Therefore, as some of these isolates displayed higher activities in comparison to references, new lipase producing bacilli were determined by presenting their genotypic diversity with DNA fingerprinting techniques.

Les lipases sont des hydrolases atypiques : principales caractéristiques et applications

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Fickers P.

2008-01-01

Full Text Available ipases are atypical hydrolases: principal characteristics and applications. Due to their kinetic and substrate specificities, triacylglycerol acyl-hydrolases or lipases are atypical enzymes. In function of their microenvironment, lipases are able to act as hydrolases in aqueous solution or as biocatalysts in organic synthesis. As hydrolases, they are responsible of the triglycerids catabolism into fatty acids and glycerol. In many organisms, this reaction plays a major role in the fat and lipid metabolism. In addition, lipases are also able to hydrolyse phospholipids and cholesterol esters. In organic solvent, lipases could catalyse reactions such as esterifications, acidolysis or alcoolysis with enantio-, regio- and chimioselectivity. Lipases form a mixed class of enzyme due to their animal, vegetal or microbial origins. All those properties led to the development of many applications in the food and chemical industries but also in the medical and therapeutic field.

Mycelium-Bound Lipase from a Locally Isolated Strain of Geotrichum candidum

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Joo Ling Loo

2014-06-01

Full Text Available Mycelium-bound lipase (MBL, from a locally isolated Geotrichum candidum strain, was produced and characterized as a natural immobilized lipase. A time course study of its lipolytic activity in 1 L liquid broth revealed the maximum MBL activity at 4 h for mycelium cells harvested after 54 h. The yield and specific activity of MBL were 3.87 g/L dry weight and 508.33 U/g protein, respectively, while less than 0.2 U/mL lipase activity was detected in the culture supernatant. Prolonged incubation caused release of the bound lipase into the growth medium. The growth pattern of G. candidum, and production and properties of MBL were not affected by the scale. The stability of mycelia harboring lipase (MBL, harvested and lyophilized after 54 h, studied at 4 °C depicted a loss of 4.3% and 30% in MBL activity after 1 and 8 months, while the activity of free lipase was totally lost after 14 days of storage. The MBL from G. candidum displayed high substrate selectivity for unsaturated fatty acids containing a cis-9 double bond, even in crude form. This unique specificity of MBL could be a direct, simple and inexpensive way in the fats and oil industry for the selective hydrolysis or transesterification of cis-9 fatty acid residues in natural triacylglycerols.

Follicle-stimulating hormone (FSH) unmasks specific high affinity FSH-binding sites in cell-free membrane preparations of porcine granulosa cells

Energy Technology Data Exchange (ETDEWEB)

Ford, K.A.; LaBarbera, A.R.

1988-11-01

The purpose of these studies was to determine whether changes in FSH receptors correlated with FSH-induced attenuation of FSH-responsive adenylyl cyclase in immature porcine granulosa cells. Cells were incubated with FSH (1-1000 ng/ml) for up to 24 h, treated with acidified medium (pH 3.5) to remove FSH bound to cells, and incubated with (125I)iodo-porcine FSH to quantify FSH-binding sites. FSH increased binding of FSH in a time-, temperature-, and FSH concentration-dependent manner. FSH (200 ng/ml) increased binding approximately 4-fold within 16 h. Analysis of equilibrium saturation binding data indicated that the increase in binding sites reflected a 2.3-fold increase in receptor number and a 5.4-fold increase in apparent affinity. The increase in binding did not appear to be due to 1) a decrease in receptor turnover, since the basal rate of turnover appeared to be very slow; 2) an increase in receptor synthesis, since agents that inhibit protein synthesis and glycosylation did not block the increase in binding; or 3) an increase in intracellular receptors, since agents that inhibit cytoskeletal components had no effect. Agents that increase intracellular cAMP did not affect FSH binding. The increase in binding appeared to result from unmasking of cryptic FSH-binding sites, since FSH increased binding in cell-free membrane preparations to the same extent as in cells. Unmasking of cryptic sites was hormone specific, and the sites bound FSH specifically. Unmasking of sites was reversible in a time- and temperature-dependent manner after removal of bound FSH. The similarity between the FSH dose-response relationships for unmasking of FSH-binding sites and attenuation of FSH-responsive cAMP production suggests that the two processes are functionally linked.

Immobilization of lipases in PSS/PEO blends and applications in esters synthesis

International Nuclear Information System (INIS)

Vecchia, Roberto D.; Nascimento, Maria G.; Soldi, Valdir

2001-01-01

Various lipases were immobilized in PSS/PEO blends and used as bio catalysts in the esterification reaction of lauric acid with n-pentanol, in hexane as a solvent for 24 h at 35 deg C. The best results in the ester conversion, were obtained by using lipase from Rhryzopus oryzae immobilized in PSS/PEO 80:20 blend. The data are in agreement with DSC and TGA values, which showed that these systems (blend/lipase) were very stable with low mass loss. No product was obtained by using lipase FAP-15 immobilized in PSS film , showing the strong influence of the polymer on enzyme activity. (author)

Bioconjugation of lipase and cholesterol oxidase with graphene or graphene oxide

Energy Technology Data Exchange (ETDEWEB)

Silva, Rubens A.; Souza, Michele L.; Bloisi, Georgia D.; Corio, Paolo; Petri, Denise F. S., E-mail: dfsp@iq.usp.br [Universidade de São Paulo, Instituto de Química (Brazil)

2015-04-15

The catalytic behavior of lipase and cholesterol oxidase (ChOx) in the absence and in the presence of graphene (G) or graphene oxide (GO) was investigated at 24 ± 1 °C and pH 6.5. GO flat sheets (0.5–2 μm) were ∼2-nm thick, while G formed aggregates. The maximum reaction velocity (V{sub max}) values and turnover numbers (k{sub cat}) determined for reactions catalyzed by physical mixtures of lipase (at 0.01 g l{sup −1}) or ChOx (at 0.03 g l{sup −1}) and G (0.012 g l{sup −1}) increased six-fold or doubled, respectively, in comparison to neat enzymes. Circular dichroism (CD) and photoluminescence (PL) spectroscopic measurements revealed the preservation of native secondary structures of enzymes and bioconjugation driven by hydrophobic interaction and energy transfer (redshift) between lipase or ChOx and G, corroborating with the enhanced catalytic behavior. On the other hand, the interactions between GO, which has hydrophilic moieties on the basal plane, and ChOx caused enzyme deactivation, as evidenced by the absence of typical CD signal. At low GO concentration (<0.012 g l{sup −1}), bioconjugates of lipases with GO led to V{sub max} and k{sub cat} values four-fold lower than their counterparts with G, but the GO hydrophilic groups probably favored the affinity for the substrate, because the Michaelis constant (K{sub m}) values decreased in comparison to that of neat lipase. Upon increasing the GO concentration, lipases lost secondary structure and the typical lipase PL bands disappeared.

Bioconjugation of lipase and cholesterol oxidase with graphene or graphene oxide

International Nuclear Information System (INIS)

Silva, Rubens A.; Souza, Michele L.; Bloisi, Georgia D.; Corio, Paolo; Petri, Denise F. S.

2015-01-01

The catalytic behavior of lipase and cholesterol oxidase (ChOx) in the absence and in the presence of graphene (G) or graphene oxide (GO) was investigated at 24 ± 1 °C and pH 6.5. GO flat sheets (0.5–2 μm) were ∼2-nm thick, while G formed aggregates. The maximum reaction velocity (V max ) values and turnover numbers (k cat ) determined for reactions catalyzed by physical mixtures of lipase (at 0.01 g l −1 ) or ChOx (at 0.03 g l −1 ) and G (0.012 g l −1 ) increased six-fold or doubled, respectively, in comparison to neat enzymes. Circular dichroism (CD) and photoluminescence (PL) spectroscopic measurements revealed the preservation of native secondary structures of enzymes and bioconjugation driven by hydrophobic interaction and energy transfer (redshift) between lipase or ChOx and G, corroborating with the enhanced catalytic behavior. On the other hand, the interactions between GO, which has hydrophilic moieties on the basal plane, and ChOx caused enzyme deactivation, as evidenced by the absence of typical CD signal. At low GO concentration (<0.012 g l −1 ), bioconjugates of lipases with GO led to V max and k cat values four-fold lower than their counterparts with G, but the GO hydrophilic groups probably favored the affinity for the substrate, because the Michaelis constant (K m ) values decreased in comparison to that of neat lipase. Upon increasing the GO concentration, lipases lost secondary structure and the typical lipase PL bands disappeared

Characterization of an extracellular lipase by Pseudomonas koreensis BK-L07 isolated from soil.

Science.gov (United States)

Anbu, Periasamy

2014-01-01

Screening using spirit blue agar revealed that strain BK-L07 had the highest lipase activity. Furthermore, the isolated strain was identified as Pseudomonas sp. based on morphological, physiological, biochemical, and molecular analyses. The 16S rRNA gene sequence of strain BK-L07 shared a high similarity with that of Pseudomonas koreensis (99%). The nutritional conditions and physicochemical properties were influenced by P. koreensis BK-L07. The maximum lipase production was obtained in tryptic soy broth medium at pH 8.0 and a temperature of 25°C after 36 hr of incubation. In addition, the lipase activity was determined using different carbon sources and lipase inducers. The lipase production was greatest when 1% maltose was used as the carbon source and olive oil was used as the lipase inducer. The lipase production was significantly increased approximately threefold in the optimized medium when compared with the original medium. Further, the lipase was purified by ammonium sulfate precipitation and gel filtration chromatography with a purification yield of 10.8%. The molecular mass of lipase was 45 kDa. The optimum temperature and pH were 40°C and 8.0, respectively. The enzyme was stable up to 50°C and at pH from 7 to 9. In addition, the enzyme activity was stimulated by MgSO4 and completely inhibited by ethylenediamine tetraacetic acid (EDTA), indicating the metalloenzyme type. The lipase activity was toward medium to long chain length of fatty acids (C10 to C18). Supplemental materials are available for this article. Go to the publisher's online edition of Preparative Biochemistry and Biotechnology to view the supplemental file.

Overexpression of Fusarium solani lipase in Pichia pastoris and its application in lipid degradation

Directory of Open Access Journals (Sweden)

Jinaporn Wongwatanapaiboon

2016-09-01

Full Text Available Fusarium solani NAN103 lipase was successfully overexpressed in Pichia pastoris using inducible expression system and constitutive expression system under the control of alcohol oxidase 1 promoter (pAOX1 and glyceraldehyde-3-phosphate dehydrogenase promoter (pGAP, respectively. Lipase obtained using the constitutive promoter showed the highest activity of 18.8 U/mg in 3 days of cultivation time. Optimal lipase activity was observed at pH 7.0 and 35 °C using p-nitrophenyl laurate as the substrate. Lipase activity was enhanced by Mn2+, Ba2+, Li+, Ca2+, Ni2+, CHAPS and Triton X-100 but was inhibited by Hg2+, Ag+ and SDS. The addition of 10% v/v of octanol, p-xylene, hexane and isopropanol increased lipase activity. Cultivation of lipase-expressing P. pastoris under pGAP in synthetic wastewater containing 1% w/v palm oil resulted in degradation of 87% of the oil within 72 h. P. pastoris expressing F. solani lipase from constitutive expression system has the potential to be used as an alternative microorganism for lipid degradation.

Primary defects in lipolysis and insulin action in skeletal muscle cells from type 2 diabetic individuals

DEFF Research Database (Denmark)

Kase, E. T.; Feng, Y. Z.; Badin, P. M.

2015-01-01

A decrease in skeletal muscle lipolysis and hormone sensitive-lipase (HSL) expression has been linked to insulin resistance in obesity. The purpose of this study was to identify potential intrinsic defects in lipid turnover and lipolysis in myotubes established from obese and type 2 diabetic...

The G-250A polymorphism in the hepatic lipase gene promoter is associated with changes in hepatic lipase activity and LDL cholesterol: The KANWU Study

DEFF Research Database (Denmark)

Lindi, Virpi; Schwab, Ursula; Louheranta, Anne

2007-01-01

BACKGROUND AND AIMS: Hepatic lipase (HL) catalyzes the hydrolysis of triglycerides and phospholipids from lipoproteins, and promotes the hepatic uptake of lipoproteins. A common G-250A polymorphism in the promoter of the hepatic lipase gene (LIPC) has been described. The aim was to study...

Development of a high-throughput liquid state assay for lipase activity using natural substrates and rhodamine B.

Science.gov (United States)

Zottig, Ximena; Meddeb-Mouelhi, Fatma; Beauregard, Marc

2016-03-01

A fluorescence-based assay for the determination of lipase activity using rhodamine B as an indicator, and natural substrates such as olive oil, is described. It is based on the use of a rhodamine B-natural substrate emulsion in liquid state, which is advantageous over agar plate assays. This high-throughput method is simple and rapid and can be automated, making it suitable for screening and metagenomics application. Reaction conditions such as pH and temperature can be varied and controlled. Using triolein or olive oil as a natural substrate allows monitoring of lipase activity in reaction conditions that are closer to those used in industrial settings. The described method is sensitive over a wide range of product concentrations and offers good reproducibility. Copyright © 2015 Elsevier Inc. All rights reserved.

Dual bioimprinting of Thermomyces lanuginosus lipase for synthesis of biodiesel

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Joyeeta Mukherjee

2016-06-01

Full Text Available Use of biodiesel as an alternative to non-renewable sources of energy has become an attractive option in recent years. The enzymatic synthesis of biodiesel by transesterification of fats/oils with an alcohol is a much more sustainable route than the chemical method. However, cost effectiveness of the enzymatic route is a major barrier in its commercialization. In this work, a high activity biocatalyst design of Thermomyces lanuginosus lipase is made by dually bioimprinting it with substrate and a surfactant (which is believed to open up the lid covering the active site of the lipase during precipitation of the lipase in organic solvent. When the lipase was bioimprinted with only the surfactants, 28 U of the enzyme/g of oil could yield 99% biodiesel from soybean oil in about 4 h. However, when dually bioimprinted even very low enzyme load 1.4 U/g of oil, yielded 99% biodiesel within 48 h.

Lipoprotein lipase and endothelial lipase in human testis and in germ cell neoplasms

DEFF Research Database (Denmark)

Nielsen, J E; Lindegaard, M L; Friis-Hansen, L

2009-01-01

. The results suggest that both EL and LPL participate in the supply of nutrients and steroidogenesis in the testes, and that especially EL may be important for the supply of cholesterol for testosterone production in the Leydig cells. The partial cellular separation of the expression of the two lipases...

Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation

NARCIS (Netherlands)

Dittmer, W.U.; Kievit, de P.; Prins, M.W.J.; Vissers, J.L.M.; Mersch, M.E.C.; Martens, M.F.W.C.

2008-01-01

A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions

Fat digestion by lingual lipase: mechanism of lipolysis in the stomach and upper small intestine.

Science.gov (United States)

Liao, T H; Hamosh, P; Hamosh, M

1984-05-01

Ten to 30% of dietary fat is hydrolyzed in the stomach by lingual lipase, an enzyme secreted from lingual serous glands. We investigated the substrate specificity of this enzyme as well as the potential of lingual lipase to act in the upper small intestine i.e., in the presence of bile salts and lecithin. The data presented show that partially purified preparations of rat lingual lipase and the lipase in gastric aspirates of newborn infants have identical substrate specificity: medium-chain triglycerides were hydrolyzed at rates 5-8-fold higher than long-chain triglycerides; the rat and human enzymes do not hydrolyze the ester bond of lecithin or cholesteryl-ester. In contrast to pancreatic lipase, the hydrolysis of triglycerides by lingual lipase is not inhibited by lecithin. But, similar to pancreatic lipase the activity of lingual lipase is inhibited by bile salts, the extent of inhibition varying with its nature and concentration. This inactivation is not prevented by colipase but is partially averted by lipids and protein, suggesting that lingual lipase can remain active in the duodenum. The pH optimum of the enzyme (2.2-6.5 in the rat and 3.5-6.0 in human gastric aspirates) is compatible with continued activity in the upper small intestine, especially during the neonatal period, when the luminal pH is under 6.5. The marked variation in lipase activity levels in gastric aspirates of newborn infants is probably due to individual variations in enzyme amounts. The characteristics of the lipase are however identical in infants with low, intermediate or high activity levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipase genes in Mucor circinelloides: identification, sub-cellular location, phylogenetic analysis and expression profiling during growth and lipid accumulation.

Science.gov (United States)

Zan, Xinyi; Tang, Xin; Chu, Linfang; Zhao, Lina; Chen, Haiqin; Chen, Yong Q; Chen, Wei; Song, Yuanda

2016-10-01

Lipases or triacylglycerol hydrolases are widely spread in nature and are particularly common in the microbial world. The filamentous fungus Mucor circinelloides is a potential lipase producer, as it grows well in triacylglycerol-contained culture media. So far only one lipase from M. circinelloides has been characterized, while the majority of lipases remain unknown in this fungus. In the present study, 47 potential lipase genes in M. circinelloides WJ11 and 30 potential lipase genes in M. circinelloides CBS 277.49 were identified by extensive bioinformatics analysis. An overview of these lipases is presented, including several characteristics, sub-cellular location, phylogenetic analysis and expression profiling of the lipase genes during growth and lipid accumulation. All of these proteins contained the consensus sequence for a classical lipase (GXSXG motif) and were divided into four types including α/β-hydrolase_1, α/β-hydrolase_3, class_3 and GDSL lipase (GDSL) based on gene annotations. Phylogenetic analyses revealed that class_3 family and α/β-hydrolase_3 family were the conserved lipase family in M. circinelloides. Additionally, some lipases also contained a typical acyltransferase motif of H-(X) 4-D, and these lipases may play a dual role in lipid metabolism, catalyzing both lipid hydrolysis and transacylation reactions. The differential expression of all lipase genes were confirmed by quantitative real-time PCR, and the expression profiling were analyzed to predict the possible biological roles of these lipase genes in lipid metabolism in M. circinelloides. We preliminarily hypothesized that lipases may be involved in triacylglycerol degradation, phospholipid synthesis and beta-oxidation. Moreover, the results of sub-cellular localization, the presence of signal peptide and transcriptional analyses of lipase genes indicated that four lipase in WJ11 most likely belong to extracellular lipases with a signal peptide. These findings provide a platform

Chicken fat and inorganic nitrogen source for lipase production by ...

African Journals Online (AJOL)

SAM

2014-03-19

Mar 19, 2014 ... for lipase production, the production cost was $US 518.00/million Units of lipase. Key words: ... energetics, fine chemicals and pulp and paper industries. ... for enzyme production is extremely important in dictating ... fat is waste product of poultry processing industry ... Economic Research Service,” 2013).

In silico modeling of lipase H | Jabeen | African Journal of ...

African Journals Online (AJOL)

LAH 2 is a type of autosomal recessive hypotrichosis that affect hairs, eyebrows, scalp and eyelashes. Mutations in Lipase H gene result in LAH 2. Changes that result from mutation on physiochemical properties, post-translational modifications, functional sites, secondary structure and tertiary structure lipase H gene (LIPH) ...

Effect of culture conditions on lipase production by Fusarium solani in batch fermentation.

Science.gov (United States)

Maia, M M; Heasley, A; Camargo de Morais, M M; Melo, E H; Morais, M A; Ledingham, W M; Lima Filho, J L

2001-01-01

Lipase (Glycerol ester hydrolase EC 3.1.1.3.) from a Brazilian strain of Fusarium solani FSI has been investigated. The effect of different carbon sources and trace elements added to basal medium was observed with the aim of improving enzyme production. Lipase specific activity was highest (0.45 U mg(-1)) for sesame oil. When this medium was supplemented with trace elements using olive oil, corn oil and sesame oil the lipase specific activity increased to 0.86, 1.89 and 1.64 U mg(-1), respectively, after 96 h cultivation without any considerable biomass increase. The Km of this lipase using pNPP (p-nitrophenylpalmitate) as substrate, was 1.8 mM with a Vmax of 1.7 micromol min(-1) mg protein(-1). Lipase activity increased in the presence of increasing concentrations of hexane and toluene. In contrast, incubation of this enzyme with water-soluble solvents decreased its activity after 10% concentration (v/v) of the solvent. The lipase activity was stable below 35 degrees C but above this temperature activity losses were observed.

Lipase From Thermoalkalophilic Pseudomonas species as an Additive in Potential Laundry Detergent Formulations

Directory of Open Access Journals (Sweden)

Ibrahim, C. O.

2009-01-01

Full Text Available Lipase isolated from a thermoalkalophilic Pseudomonas species was used as additive to improve the degree of olive oil removal from cotton fabric in the presence of surfactants. The lipase used in this study was found to be more effective with non ionic surfactants as compared to ionic surfactants. In terms of stability, there was no decrease in activity found in the presence of Tween 85, Span 80 and Span 20. Lipase from Pseudomonas species was most active in the presence of Tween 85, Span 80 and Span 20. The application of lipase from Pseudomonas species as an additive in the formulation containing Span 80 has improved oil removal by 36% using the washing system consisting 5 U/mL lipase, at 70 °C for 20 min and 0.8% of Span 80 as surfactant. Considering that lipase from Pseudomonas species is stable in high pH and temperatures in the presence of various surfactants, therefore it is suitable to be incorporated as additives in potential detergent formulations.

Characterization and spray drying of lipase produced by the endophytic fungus Cercospora kikuchii

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T. A. Costa-Silva

2014-12-01

Full Text Available A lipase from the endophytic fungus Cercospora kikuchii was purified, biochemically characterized and the effects of spray drying on stabilization of the purified enzyme were studied. The lipase was purified 9.31-fold with recovery of 26.6% and specific activity of 223.6 U/mg. The optimum pH and temperature were 4.6 and 35 ºC, respectively, while the Vmax was 10.28 µmol/min.mg-1 protein and Km 0.0324 mM. All the metal ions tested enhanced the enzyme activity. The lipase retained almost 100% activity in the presence of strong oxidants and was also resistant to Triton X, Tween 80 and 20 and SDS, as well as to proteases. The purified lipase was spray dried and kept until 85.2% of enzymatic activity. At least 70% of the enzymatic activity was maintained for spray dried purified lipase during the storage period. The lipase produced by Cercospora kikuchii has properties useful for industrial application and showed adequate stabilization and retention of its enzymatic activity after spray drying.

Disruption of growth hormone receptor gene causes diminished pancreatic islet size and increased insulin sensitivity in mice.

Science.gov (United States)

Liu, Jun-Li; Coschigano, Karen T; Robertson, Katie; Lipsett, Mark; Guo, Yubin; Kopchick, John J; Kumar, Ujendra; Liu, Ye Lauren

2004-09-01

Growth hormone, acting through its receptor (GHR), plays an important role in carbohydrate metabolism and in promoting postnatal growth. GHR gene-deficient (GHR(-/-)) mice exhibit severe growth retardation and proportionate dwarfism. To assess the physiological relevance of growth hormone actions, GHR(-/-) mice were used to investigate their phenotype in glucose metabolism and pancreatic islet function. Adult GHR(-/-) mice exhibited significant reductions in the levels of blood glucose and insulin, as well as insulin mRNA accumulation. Immunohistochemical analysis of pancreatic sections revealed normal distribution of the islets despite a significantly smaller size. The average size of the islets found in GHR(-/-) mice was only one-third of that in wild-type littermates. Total beta-cell mass was reduced 4.5-fold in GHR(-/-) mice, significantly more than their body size reduction. This reduction in pancreatic islet mass appears to be related to decreases in proliferation and cell growth. GHR(-/-) mice were different from the human Laron syndrome in serum insulin level, insulin responsiveness, and obesity. We conclude that growth hormone signaling is essential for maintaining pancreatic islet size, stimulating islet hormone production, and maintaining normal insulin sensitivity and glucose homeostasis.

18{beta}-Glycyrrhetinic acid inhibits adipogenic differentiation and stimulates lipolysis

Energy Technology Data Exchange (ETDEWEB)

Moon, Myung-Hee; Jeong, Jae-Kyo; Lee, You-Jin; Seol, Jae-Won; Ahn, Dong-Choon; Kim, In-Shik [Center for Healthcare Technology Development, Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Park, Sang-Youel, E-mail: sypark@chonbuk.ac.kr [Center for Healthcare Technology Development, Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

2012-04-20

Highlights: Black-Right-Pointing-Pointer 18{beta}-GA inhibits adipogenic differentiation in 3T3-L1 preadipocytes and stimulates lipolysis in differentiated adipocytes. Black-Right-Pointing-Pointer Anti-adipogenic effect of 18{beta}-GA is caused by down-regulation of PPAR{gamma} and inactivation of Akt signalling. Black-Right-Pointing-Pointer Lipolytic effect of 18{beta}-GA is mediated by up-regulation of HSL, ATGL and perilipin and activation of HSL. -- Abstract: 18{beta}-Glycyrrhetinic acid (18{beta}-GA) obtained from the herb liquorice has various pharmacological properties including anti-inflammatory and anti-bacterial activities. However, potential biological anti-obesity activities are unclear. In this study, novel biological activities of 18{beta}-GA in the adipogenesis of 3T3-L1 preadipocytes and in lipolysis of differentiated adipocytes were identified. Mouse 3T3-L1 cells were used as an in vitro model of adipogenesis and lipolysis, using a mixture of insulin/dexamethasone/3-isobutyl-1-methylxanthine (IBMX) to induce differentiation. The amount of lipid droplet accumulation was determined by an AdipoRed assay. The expression of several adipogenic transcription factors and enzymes was investigated using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. 18{beta}-GA dose-dependently (1-40 {mu}M) significantly decreased lipid accumulation in maturing preadipocytes. In 3T3-L1 preadipocytes, 10 {mu}M of 18{beta}-GA down-regulated the transcriptional levels of the peroxisome proliferator-activated receptor {gamma}, CCAAT/enhancer-binding protein {alpha} and adiponectin, which are markers of adipogenic differentiation via Akt phosphorylation. Also, in differentiated adipocytes, 18{beta}-GA increased the level of glycerol release and up-regulated the mRNA of hormone-sensitive lipase, adipose TG lipase and perilipin, as well as the phosphorylation of hormone-sensitive lipase at Serine 563. The results indicate that 18{beta

Lipase-catalyzed biodiesel synthesis with different acyl acceptors

Directory of Open Access Journals (Sweden)

Ognjanović Nevena D.

2008-01-01

Full Text Available Biodiesel is an alternative fuel for diesel engine that is environmentally acceptable. Conventionally, biodiesel is produced by transesterification of triglycerides and short alcohols in the presence of an acid or an alkaline catalyst. There are several problems associated with this kind of production that can be resolved by using lipase as the biocatalyst. The aim of the present work was to investigate novel acyl acceptors for biodiesel production. 2-Propanol and n-butanol have a less negative effect on lipase stability, and they also improve low temperature properties of the fuel. However, excess alcohol leads to inactivation of the enzyme, and glycerol, a major byproduct, can block the immobilized enzyme, resulting in low enzymatic activity. This problem was solved by using methyl acetate as acyl acceptor. Triacetylglycerol is produced instead of glycerol, and it has no negative effect on the activity of the lipase.

Dependence of PERT endpoint on endogenous lipase activity.

Science.gov (United States)

Gao, Wen-Yi; Mulberg, Andrew E

2014-11-01

To clarify and to understand the potential for misinterpretation of change in fecal fat quantitation during pancreatic enzyme replacement therapy (PERT) trials for treatment of exocrine pancreatic insufficiency. Analysis of clinical trials submitted to the U.S. Food and Drug Administration (FDA) for approval of PERT that enrolled 123 cystic fibrosis adult and pediatric patients treated with Creon, Pertzye, Ultresa, and Zenpep. The CFA% defines lipase activity as a percentage of converting substrate of "Total Daily Dietary Fat Intake." PERT trials performed to date have modified the definition to converting the "Shared Daily Fat Intake," generating "Partial CFA" for the exogenous lipase: the higher the activity of coexisting endogenous lipase, the lower the "Partial CFA" of exogenous measured. This review shows that "Partial CFA" is not CFA. Enrollment of patients with low HPLA during treatment may improve the interpretability of "Partial CFA" measured by PERT trials.

Novel magnetic cross-linked lipase aggregates for improving the resolution of (R, S)-2-octanol.

Science.gov (United States)

Liu, Ying; Guo, Chen; Liu, Chun-Zhao

2015-03-01

Novel magnetic cross-linked lipase aggregates were fabricated by immobilizing the cross-linked lipase aggregates onto magnetic particles with a high number of -NH2 terminal groups using p-benzoquinone as the cross-linking agent. At the optimal fabrication conditions, 100% of immobilization efficiency and 139% of activity recovery of the magnetic cross-linked lipase aggregates were achieved. The magnetic cross-linked lipase aggregates were able to efficiently resolve (R, S)-2-octanol, and retained 100% activity and 100% enantioselectivity after 10 cycles of reuse, whereas the cross-linked lipase aggregates only retained about 50% activity and 70% enantioselectivity due to insufficient cross-linking. These results provide a great potential for industrial applications of the magnetic cross-linked lipase aggregates. © 2014 Wiley Periodicals, Inc.

Novel One-Pot Green Synthesis of Indolizines Biocatalysed by Candida antarctica Lipases

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Simon Bonte

2013-02-01

Full Text Available Marine microorganisms are of considerable interest as a promising source of enzymes with unsuspected potentials as catalysts for chemical synthesis. We describe here an efficient method for one-pot indolizine synthesis that has been developed using lipase A and lipase B from Candida antarctica as biocatalysts. As showed by HPLC/MS analysis, the yield in indolizines was higher in the presence of the biocatalyst than in absence of enzyme. Lipase A, from Candida antarctica, showed high catalytic activity and selectivity for the cycloaddition reactions. When the reactions were performed under ultrasound irradiation, the Candida antarctica lipase catalyzed reactions yielded pure indolozines, in good yields and in very short time.

ZnO nanorod biosensor for highly sensitive detection of specific protein binding

International Nuclear Information System (INIS)

Kim, Jin Suk; Park, Won Il; Lee, Chul Ho; Yi, Gyu Chul

2006-01-01

We report on the fabrication of electrical biosensors based on functionalized ZnO nanorod surfaces with biotin for highly sensitive detection of biological molecules. Due to the clean interface and easy surface modification, the ZnO nanorod sensors can easily detect streptavidin binding down to a concentration of 25 nM, which is more sensitive than previously reported one-dimensional (1D) nanostructure electrical biosensors. In addition, the unique device structure with a micrometer-scale hole at the center of the ZnO nanorod's conducting channel reduces the leakage current from the aqueous solution, hence enhancing device sensitivity. Moreover, ZnO nanorod field-effect-transistor (FET) sensors may open up opportunities to create many other oxide nanorod electrical sensors for highly sensitive and selective real-time detection of a wide variety of biomolecules.

Regulation of the juvenile hormone titre in the Colorado potato beetle

NARCIS (Netherlands)

Kramer, S.J.

1978-01-01

Three main topics were investigated in regulation of the titre of juvenile hormone in haemolymph of the Colorado potato beetle ( Leptinotarsa decemlineata Say): enzymic breakdown of the hormone; binding and protection of the hormone by carrier proteins; the synthetic capacity of

Synthesis activity-based zymography for detection of lipases and esterases.

Science.gov (United States)

Kwon, Min-A; Kim, Hyun Suk; Hahm, Dae-Hyun; Song, Jae Kwang

2011-04-01

A new zymography method for lipases and esterases was developed on the basis of the esterification reaction between fatty acids and alcohols. The enzymes were separated by SDS-PAGE and native PAGE. The gel was washed and then incubated in an aqueous solution containing fatty acids (oleic acid 18:1 or caprylic acid 8:0) and dodecanol. Synthesis was visualized by in situ precipitation of water-insoluble and non-diffusible fatty acid esters, such as dodecyl oleate and dodecyl octanoate. The synthesis activity-based zymography was confirmed with different enzyme samples, including commercial lipase preparations, purified recombinant lipase and cutinase, and crude culture supernatants of lipolytic enzyme-producing soil bacteria.

Growth hormone treatment during pregnancy in a growth hormone-deficient woman

DEFF Research Database (Denmark)

Müller, J; Starup, J; Christiansen, J S

1995-01-01

Information on the course and outcome of pregnancies in growth hormone (GH)-deficient patients is sparse, and GH treatment during pregnancy in such women has not been described previously. We have studied fetal growth and serum levels of GH, insulin-like growth factor I (IGF-I) and IGF binding...

Transesterification Synthesis of Chloramphenicol Esters with the Lipase from Bacillus amyloliquefaciens

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Fengying Dong

2017-09-01

Full Text Available This work presents a synthetic route to produce chloramphenicol esters by taking advantage the high enantio- and regio-selectivity of lipases. A series of chloramphenicol esters were synthesized using chloramphenicol, acyl donors of different carbon chain length and lipase LipBA (lipase cloned from Bacillus amyloliquefaciens. Among acyl donors with different carbon chain lengths, vinyl propionate was found to be the best. The influences of different organic solvents, reaction temperature, reaction time, enzyme loading and water content on the synthesis of the chloramphenicol esters were studied. The synthesis of chloramphenicol propionate (0.25 M with 4.0 g L−1 of LipBA loading gave a conversion of ~98% and a purity of ~99% within 8 h at 50 °C in 1,4-dioxane as solvent. The optimum mole ratio of vinyl propionate to chloramphenicol was increased to 5:1. This is the first report of B. amyloliquefaciens lipase being used in chloramphenicol ester synthesis and a detailed study of the synthesis of chloramphenicol propionate using this reaction. The high enzyme activity and selectivity make lipase LipBA an attractive catalyst for green chemical synthesis of molecules with complex structures.

Influence of cosolvents on the hydrophobic surface immobilization topography of Candida antarctica lipase B

Science.gov (United States)

The presence of cosolvents and co-solutes during the immobilization of lipases on hydrophobic supports may influence the extent of lipase immobilization and the long-term catalytic stability of the biocatalyst. Candida antarctica B lipase immobilization was examined on a hydrophobic surface, i.e., ...

[The influence of hypothyroidism on the conversion and binding of thyroid hormones in patients with end-stage renal disease].

Science.gov (United States)

Dubczak, Iwanna; Niemczyk, Longin; Bartoszewicz, Zbigniew; Szamotulska, Katarzyna; Saracyn, Marek; Niemczyk, Stanisław

2017-03-21

Hypothyroidism in patients with renal failure (RF) causes many metabolic and clinical problems, and both these diseases can mutually exacerbate their disturbances. The aim of this study was to evaluate the effect of hypothyroidism, and end-stage renal disease (ESRD) on conversion of thyroid hormones (TH) in patients with ESRD treated with chronic hemodialysis (HD). The study was performed in 74 patients, including 41 women (K) and 33 men (M) aged 28-83 y.o. in 4 groups: G1 - 12 people with ESRD treated with HD and with newly diagnosed hypothyroidism without substitution (6 K and M 6) aged 66,83±12,90 y.o., G2 - 26 patients with ESRD treated with HD without hypothyroidism (10 F, 16 M) aged 58,85±15,52 y.o., G3 - 11 hypothyroid patients without RF (9 K, 2 M) aged 54,73±21,26 y.o., G4 - 25-persons from control group of healthy subjects (16 M, 9 M) aged 51,24±12,58 y.o. In all subjects the concentration of TSH and TH (T4, T3, fT4, TSH, FT3, rT3) were measured and values of conversion factors (T3/T4, FT3/ fT4, rT3/fT4 and rT3/fT3) and binding TH to protein factors (fT4/T4 and fT3/T3) were calculated. Lower concentration of T3 (p=0.012), fT3 (phypothyroidism than in healthy subjects. Renal failure with concomitant hypothyroidism intensify the disturbances of T4 to T3 conversion (p=0.034) and hypothyroidism with concomitant renal failure disrupts binding of T3 to proteins (p=0.001). FT3 to fT4 ratio in renal failure with concomitant hypothyroidism group was significantly lower than in each other group. rT3 concentrations were the highest in healthy subjects. Concomitance of hypothyroidism and end-stage renal disease reduces the conversion of thyroxine to triiodothyronine, but does not increase the production of rT3. Hypothyroidism significantly increases the disorders of thyroid hormones in end-stage renal disease. There is decreased tendency to bind of thyroid hormone to protein in hypothyroidism in patients with end-stage renal disease.

Cloning and characterization of newly isolated lipase from Enterobacter sp. Bn12.

Science.gov (United States)

Farrokh, Parisa; Yakhchali, Bagher; Karkhane, Ali Asghar

2014-01-01

A mesophilic Enterobacter sp. Bn12 producing an alkaline thermostable lipase was isolated from soil in Tehran, Iran. The lipase gene (ELBn12) was identified from a genomic library. Sequence analysis of the DNA fragment revealed an open reading frame of 879 bp encoding a lipase with a molecular mass of 31.3 kDa. The deduced amino acid sequence showed 96% identity with a lipase of Enterobacter sp. Ag1 and the identity of their DNA sequences was 88.9%. ELBn12 belongs to the lipase subfamily I.1 and its catalytic triad consists of Ser82, Asp237 and His259. The lipase was expressed in Escherichia coli (BL21) pLysS and partially purified by anion exchange chromatography. The maximum activity of ELBn12 was obtained at temperature of 60 °C and pH 8.0 towards tricaprylin (C8) and its specific activity was around 2900 U/mg. ELBn12 was stable within a broad pH range from 6.0 to 11.0. The enzyme showed high stability in both polar and nonpolar organic solvents at 50% (v/v). The lipase activity was enhanced in the presence of 10 mM of Ca(2+), Mg(2+) and K(+), while heavy metals (Fe(3+) and Zn(2+)) had strong inhibitory effect. ELBn12 showed high activity in the presence of 1% (w/v) nonionic surfactants, however ionic surfactants inhibited the lipolytic activity. ELBn12 characteristics show that it has a potential to be used in various industrial processes.

Requirement of lid2 for interfacial activation of a family I.3 lipase with unique two lid structures.

Science.gov (United States)

Cheng, Maria; Angkawidjaja, Clement; Koga, Yuichi; Kanaya, Shigenori

2012-10-01

A family I.3 lipase from Pseudomonas sp. MIS38 (PML) is characterized by the presence of two lids (lid1 and lid2) that greatly change conformation upon substrate binding. While lid1 represents the commonly known lid in lipases, lid2 is unique to PML and other family I.3 lipases. To clarify the role of lid2 in PML, a lid2 deletion mutant (ΔL2-PML) was constructed by deleting residues 35-64 of PML. ΔL2-PML requires calcium ions for both lipase and esterase activities as does PML, suggesting that it exhibits activity only when lid1 is fully open and anchored by the catalytically essential calcium ion, as does PML. However, when the enzymatic activity was determined using triacetin, the activity of PML exponentially increased as the substrate concentration reached and increased beyond the critical micellar concentration, while that of ΔL2-PML did not. These results indicate that PML undergoes interfacial activation, while ΔL2-PML does not. The activities of ΔL2-PML for long-chain triglycerides significantly decreased while its activity for fatty acid ethyl esters increased, compared with those of PML. Comparison of the tertiary models of ΔL2-PML in a closed and open conformation, which are optimized by molecular dynamics simulation, with the crystal structures of PML suggests that the hydrophobic surface area provided by lid1 and lid2 in an open conformation is considerably decreased by the deletion of lid2. We propose that the hydrophobic surface area provided by these lids is necessary to hold the micellar substrates firmly to the active site and therefore lid2 is required for interfacial activation of PML. © 2012 The Authors Journal compilation © 2012 FEBS.

A newly high alkaline lipase: an ideal choice for application in detergent formulations

Directory of Open Access Journals (Sweden)

Cherif Slim

2011-11-01

Full Text Available Abstract Background Bacterial lipases received much attention for their substrate specificity and their ability to function in extreme environments (pH, temperature.... Many staphylococci produced lipases which were released into the culture medium. Reports of thermostable lipases from Staphylococcus sp. and active in alkaline conditions are not previously described. Results A newly soil-isolated Staphylococcus sp. strain ESW secretes an induced lipase in the culture medium. The effects of temperature, pH and various components in a detergent on the activity and stability of Staphylococcus sp. lipase (SL1 were studied in a preliminary evaluation for use in detergent formulation solutions. The enzyme was highly active over a wide range of pH from 9.0 to 13.0, with an optimum at pH 12.0. The relative activity at pH 13.0 was about 60% of that obtained at pH 12.0. It exhibited maximal activity at 60°C. This novel lipase, showed extreme stability towards non-ionic and anionic surfactants after pre-incubation for 1 h at 40°C, and relative stability towards oxidizing agents. Additionally, the crude enzyme showed excellent stability and compatibility with various commercial solid and liquid detergents. Conclusions These properties added to the high activity in high alkaline pH make this novel lipase an ideal choice for application in detergent formulations.

Improved Performance of Pseudomonas fluorescens lipase by covalent immobilization onto Amberzyme

NARCIS (Netherlands)

Aslan, Yakup; Handayani, Nurrahmi; Stavila, Erythrina; Loos, Katja

2013-01-01

Objective: In this study, the conditions of covalent immobilization of Pseudomonas fluorescens lipase onto an oxirane-activated support (Amberzyme) were optimized to obtain a high activity yield. Furthermore, the operational and storage stabilities of immobilized lipase were tested. Methods: Optimum

Production of extracellular lipase by the phytopathogenic fungus Fusarium solani FS1 Produção de lipase extracelular pelo fungo fitopatogênico Fusarium solani FS1

OpenAIRE

Maria de Mascena Diniz Maia; Marcia Maria Camargo de Morais; Marcos Antonio de Morais Jr.; Eduardo Henrique Magalhães Melo; José Luiz de Lima Filho

1999-01-01

A Brazilian strain of Fusarium solani was tested for extracellular lipase production in peptone-olive oil medium. The fungus produced 10,500 U.l-1 of lipase after 72 hours of cultivation at 25oC in shake-flask at 120 rpm in a medium containing 3% (w/v) peptone plus 0.5% (v/v) olive oil. Glucose (1% w/v) was found to inhibit the inductive effect of olive oil. Peptone concentrations below 3% (w/v) resulted in a reduced lipase production while increased olive oil concentration (above 0.5%) did n...

Nuclear receptors for triiodothyronine. Part 1. Binding of triiodothyronine (T3) in rat liver nuclei after in vivo administration of labelled hormone

International Nuclear Information System (INIS)

Kubica, A.; Nauman, A.; Witkowska, E.; Nauman, J.

1977-01-01

The binding of T 3 ( 125 I) has been studied in liver nuclei prepared after in vivo administration of hormone to male Wistar rats. The preliminary study revealed that 30 minutes after administration of T 3 ( 125 I) in doses varied from 5 ng to 200 ng/100 g of body weight about 20% of total radioactivity was accumulated in the liver. The ratio of T 3 in serum to T 3 in liver was found to be almost stable (regardless of dose injected) with its value between 0.2 to 0.3. To purified nuclear fraction (prepared from liver homogenates made in 0.32 M sucrose + 1 mM magnesium chloride and ultracentrifuged through 2.4 M sucrose density gradient) contained about 4% of radioactivity present in liver. When distribution of in vivo administrated T 3 ( 125 I) in the nuclear fraction was examined it was found that 2.4 - 8.2% of radioactivity present in nuclei is unspecifically bound in external nuclear membrane. The remaining part of hormone was bound specifically to nuclei. About 10% of radioactivity in nuclei without outer membrane was presented in nucleoli. Saturation study and Scatchard analysis of results obtained revealed the presence of two classes of T 3 binding sites in the liver nuclei. The first class posses high affinity and limited maximal capacity being 2.4 ng of T 3 /g of liver tissue. The second class of binding sites have had lower affinity and maximal capacity around 20 ng of T 3 /g of liver tissue. The nuclear receptors were extracted with 0.4 M KCl - the procedure known to extract non-histone proteins and nucleic acids. Further study shown the presence of one class of specific T 3 binding sites in KCl extract with maximal capacity 800 pg T 3 /mg of protein. (author)

Direct solid phase radioimmunoassay for chicken lipoprotein lipase

International Nuclear Information System (INIS)

Cheung, A.H.; Bensadoun, A.; Cheng, C.

1979-01-01

A direct, noncompetitive immunoassay for chicken lipoprotein lipase (LPL) was developed. Antibodies to LPL were purified by immunoadsorption chromatography of goat antisera on an LPL-Sepharose column. Purified anti-LPL immunoglobulins were coupled covalently to hydrophilic polyacrylamide beads by a carbodiimide reagent. An excess amount of these beads was incubated with the sample on the standard to be assayed. The amount of LPL immobilized by the heads was then detected by an excess amount of 125 I-labeled anti-LPL immunoglobulin. A linear relationship was obtained between the radioactivity bound and the amount of highly purified LPL used as a standard. The range of the assay was from 0.1 to 1.1 ng PLP. The assay was specific for chicken LPL and showed no cross-reactivity with liver lipase. It does not distinguish heat-inactivated from catalytically active enzyme species. This assay should be useful in studies of lipoprotein lipase where both catalytic activity and enzyme mass need to be quantitated

Effect of Ascorbic Acid on Lipoprotein Lipase Activity | Kotze | South ...

African Journals Online (AJOL)

Baboons kept on hypovitaminotic C diets, but without clinical signs of scurvy, had significantly higher heart muscle lipoprotein lipase activity than baboons on vitamin C 34 mg/kg body mass/day. When the serum vitamin C levels were above 0,35 mg/100 ml the heart muscle lipoprotein lipase was repressed. Serum vitamin C ...

Oral lipase activities and fat-taste receptors for fat-taste sensing in chickens.

Science.gov (United States)

Kawabata, Yuko; Kawabata, Fuminori; Nishimura, Shotaro; Tabata, Shoji

2018-01-01

It has been reported that a functional fat-taste receptor, GPR120, is present in chicken oral tissues, and that chickens can detect fat taste in a behavioral test. However, although triglycerides need to be digested to free fatty acids to be recognized by fat-taste receptors such as GPR120, it remains unknown whether lipase activities exist in chicken oral tissues. To examine this question, we first cloned another fat-taste receptor candidate gene, CD36, from the chicken palate. Then, using RT-PCR, we determined that GPR120 and CD36 were broadly expressed in chicken oral and gastrointestinal tissues. Also by RT-PCR, we confirmed that several lipase genes were expressed in both oral and gastrointestinal tissues. Finally, we analyzed the lipase activities of oral tissues by using a fluorogenic triglyceride analog as a lipase substrate. We found there are functional lipases in oral tissues as well as in the stomach and pancreas. These results suggested that chickens have a basic fat-taste reception system that incorporates a triglycerides/oral-lipases/free fatty acids/GPR120 axis and CD36 axis. Copyright © 2017 Elsevier Inc. All rights reserved.

Improvement of lipase production from Geotrichum sp. in shaken flasks

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Maldonadoa Resende Rafael

2012-01-01

Full Text Available This work is focused on the study of different variables on inoculum build-up aiming to improve the lipase production by Geotrichum sp. by means a sequential strategy of experimental design. The effects of inoculum size, corn steep liquor concentration, volume of inoculum, pH of medium, age of inoculum and soybean oil concentration on lipase activity were assessed by means of two factorial experimental designs. A maximum lipase activity of 35.20±0.8 U/mL was obtained with a inoculum composed of one circular area of 0.78cm2 containing spores, 50 mL of inoculum volume medium, 12 hours of inoculum age, 15% w/v of corn steep liquor concentration, 1.0%w/v of soybean oil concentration and initial pH 5.0 at 30°C and 150 rpm in flasks. This work showed that an enhancement of lipase activity can be obtained using a sequential statistical factorial approach to define the variables for inoculum build-up.

Lipase-Secreting Bacillus Species in an Oil-Contaminated Habitat: Promising Strains to Alleviate Oil Pollution

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Li Pin Lee

2015-01-01

Full Text Available Lipases are of great interest for different industrial applications due to their diversity and versatility. Among different lipases, microbial lipases are preferable due to their broad substrate specificity, and higher stability with lower production costs compared to the lipases from plants and animals. In the past, a vast number of bacterial species have been reported as potential lipases producers. In this study, the lipases-producing bacterial species were isolated from an oil spillage area in the conventional night market. Isolated species were identified as Bacillus species by biochemical tests which indicate their predominant establishment, and further screened on the agar solid surfaces using lipid and gelatin as the substrates. Out of the ten strains tested, four potential strains were subjected to comparison analysis of the lipolytic versus proteolytic activities. Strain 10 exhibited the highest lipolytic and proteolytic activity. In all the strains, the proteolytic activity is higher than the lipolytic activity except for strain 8, suggesting the possibility for substrate-based extracellular gene induction. The simultaneous secretion of both the lipase and protease is a mean of survival. The isolated bacterial species which harbour both lipase and protease enzymes could render potential industrial-based applications and solve environmental issues.

Polyethyleneimine-modified superparamagnetic Fe3O4 nanoparticles for lipase immobilization: Characterization and application

International Nuclear Information System (INIS)

Khoobi, Mehdi; Motevalizadeh, Seyed Farshad; Asadgol, Zahra; Forootanfar, Hamid; Shafiee, Abbas; Faramarzi, Mohammad Ali

2015-01-01

Magnetically separable nanospheres consisting of polyethyleneimine (PEI) and succinated PEI grafted on silica coated magnetite (Fe 3 O 4 ) were prepared and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, vibrating sample magnetometer, scanning electron microscopy and transmission electron microscopy. The prepared magnetic nanoparticles were then applied for physical adsorption or covalent attachment of Thermomyces lanuginosa lipase (TLL) via glutaraldehyde or hexamethylene diisocyanate. The reusability, storage, pH and thermal stabilities of the immobilized enzymes compared to that of free lipase were examined. The obtained results showed that the immobilized lipase on MNPs@PEI-GLU was the best biocatalyst which retained 80% of its initial activity after 12 cycles of application. The immobilized lipase on the selected support (MNPs@PEI-GLU) was also applied for the synthesis of ethyl valerate. Following 24 h incubation of the immobilized lipase on the selected support in n-hexane and solvent free media, the esterification percentages were 72.9% and 28.9%, respectively. - Graphical abstract: A schematic of the preparation of PEI- and succinated PEI-grafted Fe 3 O 4 MNPs (MNPs@PEI) and the immobilization of lipase by covalent bonding and adsorption. - Highlights: • Functionalized polyethylenimine-grafted magnetic nanoparticles were synthesized. • The prepared supports were fully characterized by various analysis methods. • Lipase was immobilized on the nanostructures by adsorption and covalent attachment. • Immobilized lipase produced ethyl valerate in solvent free medium

Does breastfeeding influence future sperm quality and reproductive hormones?

DEFF Research Database (Denmark)

Laustsen, J M; Jensen, M S; Thulstrup, Ane Marie

2011-01-01

was not statistically significantly associated with sperm concentration, total sperm count, sperm motility or morphology, oligozoospermia, follicle-stimulating hormone, inhibin B, luteinizing hormone, sex hormone-binding globulin (SHBG), the calculated level of free testosterone, free oestradiol, the free testosterone...... testosterone nor free oestradiol was different between the two groups. This study shows no association between breastfeeding and sperm quality or reproductive hormones and a strong association is unlikely. A larger study would be needed to detect more subtle effects....

Antitumor Responses Stimulated by Dendritic Cells Are Improved by Triiodothyronine Binding to the Thyroid Hormone Receptor β.

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Alamino, Vanina A; Mascanfroni, Iván D; Montesinos, María M; Gigena, Nicolás; Donadio, Ana C; Blidner, Ada G; Milotich, Sonia I; Cheng, Sheue-Yann; Masini-Repiso, Ana M; Rabinovich, Gabriel A; Pellizas, Claudia G

2015-04-01

Bidirectional cross-talk between the neuroendocrine and immune systems orchestrates immune responses in both physiologic and pathologic settings. In this study, we provide in vivo evidence of a critical role for the thyroid hormone triiodothyronine (T3) in controlling the maturation and antitumor functions of dendritic cells (DC). We used a thyroid hormone receptor (TR) β mutant mouse (TRβPV) to establish the relevance of the T3-TRβ system in vivo. In this model, TRβ signaling endowed DCs with the ability to stimulate antigen-specific cytotoxic T-cell responses during tumor development. T3 binding to TRβ increased DC viability and augmented DC migration to lymph nodes. Moreover, T3 stimulated the ability of DCs to cross-present antigens and to stimulate cytotoxic T-cell responses. In a B16-OVA mouse model of melanoma, vaccination with T3-stimulated DCs inhibited tumor growth and prolonged host survival, in part by promoting the generation of IFNγ-producing CD8(+) T cells. Overall, our results establish an adjuvant effect of T3-TRβ signaling in DCs, suggesting an immediately translatable method to empower DC vaccination approaches for cancer immunotherapy. ©2015 American Association for Cancer Research.

Aplicação de lipase e monoglicerídeo em pão de forma enriquecido com fibras Application of lipase and monoglyceride in fiber enriched pan bread

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Kelly Moreira Gandra

2008-03-01

Full Text Available Neste trabalho, estudou-se a aplicação da enzima lipase e do emulsificante monoglicerídeo em pão de forma enriquecido com fibras, com o objetivo de verificar a possibilidade de substituição do emulsificante pela enzima. Inicialmente, foi realizada a caracterização das matérias-primas principais (farinha e farelo de trigo. Os pães de forma foram elaborados pelo método de massa direta. Foi utilizado um planejamento experimental do tipo composto central rotacional com duas variáveis independentes: i dosagem de lipase; e ii dosagem de monoglicerídeo e, paralelamente, realizou-se um teste controle (sem adição de lipase e monoglicerídeo para comparação. As variáveis dependentes foram as características de qualidade dos pães: i volume específico; ii aceitação sensorial (aparência, textura, aroma e sabor; e iii vida de prateleira avaliada pela umidade do miolo e firmeza dos pães após 1, 4 e 7 dias do forneamento. Dentro das faixas estudadas, foi possível verificar que somente a umidade dos pães no quarto e sétimo dia após o processamento foi influenciada pela variação das dosagens de lipase e monoglicerídeo. Na avaliação sensorial, verificou-se que as notas médias atribuídas aos pães do teste controle foram inferiores à menor nota média dos ensaios do planejamento experimental, com exceção do sabor e aroma. Como não foi possível obter modelos matemáticos para todas as respostas, foram selecionados os ensaios 5 (1% monoglicerídeo, 7 (25 ppm lipase e 9 (25 ppm lipase e 1% monoglicerídeo do planejamento experimental, e o teste controle, para a avaliação dos resultados por análise de variância. Nas condições em que os ensaios foram conduzidos e para as faixas de lipase (0 a 50 ppm e monoglicerídeo (0 a 2% estudadas, verificou-se a possibilidade de substituir o monoglicerídeo por lipase em formulação de pão de forma enriquecido com fibras.In this work, the application of lipase and monoglyceride in

Enzymatic Production of FAME Biodiesel with Soluble Lipases

DEFF Research Database (Denmark)

T. Gundersen, Maria; Heltborg, Carsten Kirstejn; Yang, V

Biodiesel is a viable alternative to fossil fuels, and biocatalysis is gaining interest as a greener process. We focus on converting oils to Fatty Acid Methyl Ester (FAME) using soluble lipases, which offer an advantage compared to immobilized enzymes by cost efficiency and ease of implementation...... the defined operating space concerning: temperature, water content, initial methanol concentration and enzyme content. The identified optimum range was experimentally evaluated, and model findings were confirmed. Another barrier in lipase use in biodiesel production is the higher melting point (m...

New ether-functionalized ionic liquids for lipase-catalyzed synthesis of biodiesel.

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Zhao, Hua; Song, Zhiyan; Olubajo, Olarongbe; Cowins, Janet V

2010-09-01

Ionic liquids (ILs) are being explored as solvents for the enzymatic methanolysis of triglycerides. However, most available ILs (especially hydrophobic ones) have poor capability in dissolving lipids, while hydrophilic ILs tend to cause enzyme inactivation. Recently, we synthesized a new type of ether-functionalized ionic liquids (ILs) carrying anions of acetate or formate; they are capable of dissolving a variety of substrates and are also lipase-compatible (Green Chem., 2008, 10, 696-705). In the present study, we carried out the lipase-catalyzed transesterifications of Miglyol oil 812 and soybean oil in these novel ILs. These ILs are capable of dissolving oils at the reaction temperature (50 degrees C); meanwhile, lipases maintained high catalytic activities in these media even in high concentrations of methanol (up to 50% v/v). High conversions of Miglyol oil were observed in mixtures of IL and methanol (70/30, v/v) when the reaction was catalyzed by a variety of lipases and different enzyme preparations (free and immobilized), especially with the use of two alkylammonium ILs 2 and 3. The preliminary study on the transesterification of soybean oil in IL/methanol mixtures further confirms the potential of using oil-dissolving and lipase-stabilizing ILs in the efficient production of biodiesels.

A quantitative assay measuring the function of lipase maturation factor 1

Science.gov (United States)

Yin, Fen; Doolittle, Mark H.; Péterfy, Miklós

2009-01-01

Newly synthesized lipoprotein lipase (LPL) and related members of the lipase gene family require an endoplasmic reticulum maturation factor for attainment of enzyme activity. This factor has been identified as lipase maturation factor 1 (Lmf1), and mutations affecting its function and/or expression result in combined lipase deficiency (cld) and hypertriglyceridemia. To assess the functional impact of Lmf1 sequence variations, both naturally occurring and induced, we report the development of a cell-based assay using LPL activity as a quantitative reporter of Lmf1 function. The assay uses a cell line homozygous for the cld mutation, which renders endogenous Lmf1 nonfunctional. LPL transfected into the mutant cld cell line fails to attain activity; however, cotransfection of LPL with wild-type Lmf1 restores its ability to support normal lipase maturation. In this report, we describe optimized conditions that ensure the detection of a complete range of Lmf1 function (full, partial, or complete loss of function) using LPL activity as the quantitative reporter. To illustrate the dynamic range of the assay, we tested several novel mutations in mouse Lmf1. Our results demonstrate the ability of the assay to detect and analyze Lmf1 mutations having a wide range of effects on Lmf1 function and protein expression. PMID:19471043

Stereoselectivity of Mucorales lipases toward triradylglycerols--a simple solution to a complex problem.

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Scheib, H.; Pleiss, J.; Kovac, A.; Paltauf, F.; Schmid, R. D.

1999-01-01

The lipases from Rhizopus and Rhizomucor are members of the family of Mucorales lipases. Although they display high sequence homology, their stereoselectivity toward triradylglycerols (sn-2 substituted triacylglycerols) varies. Four different triradylglycerols were investigated, which were classified into two groups: flexible substrates with rotatable O'-C1' ether or ester bonds adjacent to C2 of glycerol and rigid substrates with a rigid N'-C1' amide bond or a phenyl ring in sn-2. Although Rhizopus lipase shows opposite stereopreference for flexible and rigid substrates (hydrolysis in sn-1 and sn-3, respectively), Rhizomucor lipase hydrolyzes both groups of triradylglycerols preferably in sn-1. To explain these experimental observations, computer-aided molecular modeling was applied to study the molecular basis of stereoselectivity. A generalized model for both lipases of the Mucorales family highlights the residues mediating stereoselectivity: (1) L258, the C-terminal neighbor of the catalytic histidine, and (2) G266, which is located in a loop contacting the glycerol backbone of a bound substrate. Interactions with triradylglycerol substrates are dominated by van der Waals contacts. Stereoselectivity can be predicted by analyzing the value of a single substrate torsion angle that discriminates between sn-1 and sn-3 stereopreference for all substrates and lipases investigated here. This simple model can be easily applied in enzyme and substrate engineering to predict Mucorales lipase variants and synthetic substrates with desired stereoselectivity. PMID:10210199

The influence of caloric deprivation and food composition on TSH, thyroid hormones and nuclear binding of T3 in mononuclear blood cells in obese women

DEFF Research Database (Denmark)

Matzen, L E; Kvetny, J

1989-01-01

In vivo changes in thyroid-stimulating hormone (TSH), thyroxin (T4), triiodothyronine (T3) and nuclear binding of T3 (NBT3) in mononuclear blood cells were studied in obese women during seven days of caloric deprivation (maximum 1,100 kcal/d). In seven women given a high protein diet (80% protein...

Protein Engineering and Homologous Expression of Serratia marcescens Lipase for Efficient Synthesis of a Pharmaceutically Relevant Chiral Epoxyester.

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Chen, Ke-Cai; Zheng, Ming-Min; Pan, Jiang; Li, Chun-Xiu; Xu, Jian-He

2017-10-01

The lipase isolated from Serratia marcescens (LipA) is a useful biocatalyst for kinetic resolution of a pharmaceutically relevant epoxyester, (±)-3-(4'-methoxyphenyl) glycidic acid methyl ester [(±)-MPGM], to afford optically pure (-)-MPGM, a key intermediate for the synthesis of diltiazem hydrochloride. Two mutants, LipA L315S and LipA S271F , were identified from the combinatorial saturation mutation library of 14 amino acid residues lining the substrate-binding pocket. LipA L315S , LipA S271F , and their combination LipA L315S/S271F showed 2.6-, 2.2-, and 4.6-fold improvements in their specific activities towards para-nitrophenyl butyrate (pNPB), respectively. Among these positive mutants, LipA S271F displayed a 3.5-fold higher specific activity towards the pharmaco substrate (±)-MPGM. Kinetic study showed that the improvement in catalytic efficiency of LipA S271F against (±)-MPGM was mainly resulted from the enhanced affinity between substrate and enzyme, as indicated by the decrease of K m . Furthermore, to address the insoluble expression issue in Escherichia coli, the homologous expression of LipA gene in S. marcescens was achieved by introducing it into an expression vector pUC18, resulting in ca. 20-fold higher lipase production. The significantly improved volumeric production and specific activity of S. marcescens lipase make it very attractive as a new-generation biocatalyst for more efficient and economical manufacturing of (-)-MPGM.

Synthesis and in vitro anti-cancer evaluation of luteinizing hormone-releasing hormone-conjugated peptide.

Science.gov (United States)

Deng, Xin; Qiu, Qianqian; Ma, Ke; Huang, Wenlong; Qian, Hai

2015-11-01

Luteinizing hormone-releasing hormone (LHRH) is a decapeptide hormone released from the hypothalamus and shows high affinity binding to the LHRH receptors. It is reported that several cancer cells also express LHRH receptors such as breast, ovarian, prostatic, bladder and others. In this study, we linked B1, an anti-cancer peptide, to LHRH and its analogs to improve the activity against cancer cells with LHRH receptor. Biological evaluation revealed that TB1, the peptide contains triptorelin sequence, present favorable anti-cancer activity as well as plasma stability. Further investigations disclosed that TB1 trigger apoptosis by activating the mitochondria-cytochrome c-caspase apoptotic pathway, it also exhibited the anti-migratory effect on cancer cells.

Increased plasma concentrations of vitamin D metabolites and vitamin D binding protein in women using hormonal contraceptives: a cross-sectional study

DEFF Research Database (Denmark)

Liendgaard, Ulla Kristine Møller; við Streym, Susanna; Jensen, Lars Thorbjørn

2013-01-01

UNLABELLED: Use of hormonal contraceptives (HC) may influence total plasma concentrations of vitamin D metabolites. A likely cause is an increased synthesis of vitamin D binding protein (VDBP). Discrepant results are reported on whether the use of HC affects free concentrations of vitamin D...... metabolites. AIM: In a cross-sectional study, plasma concentrations of vitamin D metabolites, VDBP, and the calculated free vitamin D index in users and non-users of HC were compared and markers of calcium and bone metabolism investigated. RESULTS: 75 Caucasian women aged 25-35 years were included during......, parathyroid hormone, and calcitonin, p > 0.21) or bone metabolism (plasma bone specific alkaline phosphatase, osteocalcin, and urinary NTX/creatinine ratio) between groups. IN CONCLUSION: Use of HC is associated with 13%-25% higher concentrations of total vitamin D metabolites and VDBP. This however...

High-level expression and characterization of a chimeric lipase from Rhizopus oryzae for biodiesel production.

Science.gov (United States)

Yu, Xiao-Wei; Sha, Chong; Guo, Yong-Liang; Xiao, Rong; Xu, Yan

2013-02-21

Production of biodiesel from non-edible oils is receiving increasing attention. Tung oil, called "China wood oil" is one kind of promising non-edible biodiesel oil in China. To our knowledge, tung oil has not been used to produce biodiesel by enzymatic method. The enzymatic production of biodiesel has been investigated extensively by using Rhizopus oryzae lipase as catalyst. However, the high cost of R. oryzae lipase remains a barrier for its industrial applications. Through different heterologous expression strategies and fermentation techniques, the highest expression level of the lipase from R. oryzae reached 1334 U/mL in Pichia pastoris, which is still not optimistic for industry applications. The prosequence of lipases from Rhizopus sp. is very important for the folding and secretion of an active lipase. A chimeric lipase from R. oryzae was constructed by replacing the prosequence with that from the R. chinensis lipase and expressed in P. pastoris. The maximum activity of the chimera reached 4050 U/mL, which was 11 fold higher than that of the parent. The properties of the chimera were studied. The immobilized chimera was used successfully for biodiesel production from tung oil, which achieved higher FAME yield compared with the free chimeric lipase, non-chimeric lipase and mature lipase. By response surface methodology, three variables, water content, methanol to tung oil molar ratio and enzyme dosage were proved to be crucial parameters for biosynthesis of FAME and the FAME yield reached 91.9±2.5% at the optimized conditions by adding 5.66 wt.% of the initial water based on oil weight, 3.88 of methanol to tung oil molar ratio and 13.24 wt.% of enzyme concentration based on oil weight at 40°C. This is the first report on improving the expression level of the lipase from R. oryzae by replacing prosequences. The immobilized chimera was used successfully for biodiesel production from tung oil. Using tung oil as non-edible raw material and a chimeric lipase

Inhibition of pancreatic lipase and amylase by extracts of different spices and plants.

Science.gov (United States)

Sellami, Mohamed; Louati, Hanen; Kamoun, Jannet; Kchaou, Ali; Damak, Mohamed; Gargouri, Youssef

2017-05-01

The aim of this study is to search new anti-obesity and anti-diabetic agents from plant and spices crude extracts as alternative to synthetic drugs. The inhibitory effect of 72 extracts was evaluated, in vitro, on lipase and amylase activities. Aqueous extracts of cinnamon and black tea exhibited an appreciable inhibitory effect on pancreatic amylase with IC 50 values of 18 and 87 μg, respectively. Aqueous extracts of cinnamon and mint showed strong inhibitory effects against pancreatic lipase with IC 50 of 45 and 62 μg, respectively. The presence of bile salts and colipase or an excess of interface failed to restore the lipase activity. Therefore, the inhibition of pancreatic lipase, by extracts of spices and plants, belongs to an irreversible inhibition. Crude extract of cinnamon showed the strongest anti-lipase and anti-amylase activities which offer a prospective therapeutic approach for the management of diabetes and obesity.

Fat digestion in the stomach: stability of lingual lipase in the gastric environment.

Science.gov (United States)

Fink, C S; Hamosh, P; Hamosh, M

1984-03-01

Digestion of dietary fat starts in the stomach, where lingual lipase hydrolyzes triglycerides to free fatty acids and partial glycerides at pH 3.0-6.0. Lingual lipase is secreted continuously from lingual serous glands and accumulates in the stomach between meals, when gastric pH is less than 3.0. We have, therefore, examined the resistance of lingual lipase to low pH and its possible protection by dietary components present in the stomach contents. Partially purified rat lingual lipase (7-15 micrograms enzyme protein) was preincubated at 37 degrees C for 10-60 min at pH 1.0-6.0 before incubation for assay of lipolytic activity, hydrolysis of tri-[3H]olein at pH 5.4. The data show that partially purified rat lingual lipase preparations are stable at 37 degrees C in the pH range of 2.5-6.0. Enzyme activity, however, is rapidly and irreversibly lost during preincubation at pH 1.0-2.4 for 10-30 min. Protein (gelatin 1% or albumin 1% or 2.5%) cannot prevent the inactivation of lingual lipase at low pH. The large molecular species (molecular weight greater than 500,000) of lingual lipase (thought to be an aggregate of enzyme with lipids) is slightly more resistant to inactivation than the 46,000 dalton preparation, suggesting that lipids might protect the enzyme from inactivation. Indeed, about 60% of the initial lipase activity is preserved during incubation at pH 2.0 in the presence of 50 mM lecithin or 10 mM triolein. The data indicate that triglycerides which are hydrolyzed by this enzyme as well as phospholipids that are not hydrolyzed can prevent the inactivation of the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Postmenopausal sex hormones in relation to body fat distribution