Showing papers on "Lipase published in 1978"
TL;DR: It can be concluded that the adipose conversion does not depend upon external lipids or lipoproteins for its induction; rather the differentiation program is built into the cell type and comes into operation when growth is arrested even in their absence.
145 citations
TL;DR: It is concluded that the bile salt-stimulated milk lipase is active in the infant's intestine and may contribute to the digestion of the milk lipids, particularly the retinol esters, which must be hydrolyzed before they are absorbed.
Abstract: Bile Salt-Stimulated Lipase in Human Milk: Evidence of Activity in Vivo and of a Role in the Digestion of Milk Retinol Esters
132 citations
TL;DR: Lipase, isolated from the pancreas of the dogfish, was found to activate and to bind in solution to porcine pancreatic lipase, and support the sequential idea of lipolysis whereby colipase binds substrate first, then lipase binds to colipases.
103 citations
TL;DR: A sphingomyelinase was purified 980-fold with recovery of 25.6% from the culture broth of Bacillus cereus, by (NH4)2SO4 precipitation and chromatography on CM-Sephadex, DEAE-cellulose and SephadeX G-75.
96 citations
TL;DR: The results show that a crushed food homogenate has a greater stimulative effect on pancreatic enzyme secretion than the elemental solutions and that this can be directly related to its greater nitrogen content.
Abstract: Pancreatic secretion of lipase and chymotrypsin in response to elemental diets and a crushed food homogenate was studied in normal subjects. The solutions were infused at constant flow rates at the ligament of Treitz with polyethylene glycol as a nonabsorbable marker. A triple lumen tube was used, enabling collection of secretions at 35 and 70 cm from the infusion point. The results show that a crushed food homogenate has a greater stimulative effect on pancreatic enzyme secretion than the elemental solutions and that this can be directly related to its greater nitrogen content. The osmolality of the infused solutions does not appear to be important. The relative merits of the solutions tested and total parental nutrition in reducing pancreatic enzyme secretion are discussed.
84 citations
TL;DR: Almost all of the fibers tested caused a significant loss of lipase activity and a part of the enzyme solution was absorbed into the fiber matrix thereby decreasing the availability of total filterable enzyme activity in vitro.
Abstract: Wheat bran, whole alfalfa, rice bran, safflower meal, cellulose acetate, xylan, Solka-Floc and pectin were tested for their ability to affect lipase, trypsin and chymotrypsin activity in vitro. Almost all of the fibers tested, excluding pectin, caused a significant loss of lipase activity. Incubation with Solka-Floc and xylan resulted in some loss of chymotrypsin activity. Alfalfa and safflower meal exerted the most potent effect on trypsin activity and Solka-Floc had a slight effect. With all the fibers tested, a part of the enzyme solution was absorbed into the fiber matrix thereby decreasing the availability of total filterable enzyme activity in vitro.
84 citations
TL;DR: The presented data suggest that in vivo the heparin-releasable liver lipase is mainly (85–92%) located at the surface of non-parenchymal cells.
76 citations
TL;DR: It is postulated that an important function of bile salts in the intestinal lumen is to clear the interface of the dietary fat from proteins of exo- and endogeneous sources thus making it available for pancreatic lipolysis.
75 citations
TL;DR: Although the lipase in the glyoxysomes had the highest activity, it had to cooperate with lipases in other cellular compartments for the complete hydrolysis of reserve triglycerides.
Abstract: The castor-bean endosperm-the best-studied material of reserve lipid hydrolysis in seed germination-was previously shown to have an acid lipase and an alkaline lipase having reciprocal patterns of development during germination. We studied oil seeds from 7 species, namely castor bean (Ricinus communis L.), peanut (Arachis hypogaea L.), sunflower (Helianthus annus L.), cucumber (Cucumis sativus L.), cotton (Gossypisum hirsutum L.), corn (Zea mays. L.) and tomato (Lycopersicon esculentum Mill.). The storage tissues of all these oil seeds except castor bean contained only alkaline lipase activity which increased drastically during germination. The pattern of acid and alkaline lipases in castor bean does not seem to be common in other oil seeds. The alkaline lipase of peanut cotyledons was chosen for further study. On sucrose gradient centrifugation of cotyledon homogenate from 3-d-old seedlings, about 60% of the activity of the enzyme was found to be associated with the glyoxysomes, 15% with the mitochondria, and 25% with a membrane fraction at a density of 1.12 g cm-3. The glyoxysomal lipase was associated with the organelle membrane, and hydrolyzed only monoglyceride whereas the mitochondrial and membrane-fraction enzymes degraded mono-, di- and triglycerides equally well. Thus, although the lipase in the glyoxysomes had the highest activity, it had to cooperate with lipases in other cellular compartments for the complete hydrolysis of reserve triglycerides.
58 citations
TL;DR: In this article, the authors describe the Hydrolysis of polyesters by Rhizopus delemar Lipase and show that the resulting polyesters can be used for agricultural and biological applications.
Abstract: (1978). Hydrolysis of Polyesters by Rhizopus delemar Lipase. Agricultural and Biological Chemistry: Vol. 42, No. 5, pp. 1071-1072.
57 citations
TL;DR: Both lipase and esterase activities were present in intestinal contents of all newborns studied, from the first day of life to the second, in contrast to adults given a test meal, where both activities decreased markedly in infants on feeding.
Abstract: Both lipase and esterase activities were present in intestinal contents of all newborns studied, from the first day of life. In adults given a test meal lipase activity increased and esterase activity remained unchanged. In contrast, both activities decreased markedly in infants on feeding. During the digestion of the test meal the lipase activity in intestinal contents of the infants was much lower than in adults (ratio of median values 1:27) and the esterase activity was also several fold lower (ratio of median values 1:1.3). Speculation Newborn infants often absorb lipids less efficiently than adults. One contributing factor may be that their incompletely developed pancreas responds to feedings with comparatively low outputs of lipolytic enzymes. The newborn may be more dependent than adults on auxiliary sources of lipase activity such as the pharyngeal lipase and/or the bile-stimulated lipase in human milk.
TL;DR: In rapeseed cotyledons lipase activity is associated only with a discrete microsomal membrane fraction which sediments differently from membrane fractions of the endoplasmic reticulum, which appears to depend on nitrogen nutrition of the seedlings.
Abstract: In homogenates of resting rapeseeds no lipase activity (glycerolester hydrolase, EC 3.1.1.3) could be detected using a titrimetric assay procedure. Following a 30-h lag-phase after imbibition, lipase activity increased sharply, reaching its maximum at day 4 after sowing. Simultaneously triglyceride content of the cotyledons decreased sharply. At any time during the 11-day period of seedling growth examined, only an alkaline lipase activity with a pH optimum around 9 was present. White light had essentially no effect on the development of lipase activity. However, the disappearance of lipase activity from the cotyledons after fat utilization was found to depend on nitrogen nutrition of the seedlings. The activities of the glyoxysomal enzymes catalase and malate synthetase showed the usual rise and fall patterns with peak activities at day 4 after sowing, independently of the mineral nutrition of the seedlings.
TL;DR: A modified procedure for purifying porcine pancreatic lipase (triacyglycerol acyl-hydrodrolase, EC 3.1.3) is described, which is more rapid, more reproducible and results in a purer enzyme preparation.
TL;DR: The results of this study suggest that lipolytic activity of lysosomal origin is the main source of hormone-sensitive endogenous triacylglycerol hydrolysis.
TL;DR: A model is proposed according to which lipolysis under physiological conditions would occur in two steps requiring two cofactors, and colipase would be necessary for the formation of the lipase-bile lipoprotein complex, and bile lipids would be required to direct the adsorption of this lipolytic entity toward the emulsified substrate.
Abstract: The adsorption isotherms of bile salts, phospholipids, and cholesterol were determined with siliconized glass beads. It was observed that the molar fractions of cholesterol, phospholipid, and bile polypeptide fractions increased simultaneously and considerably on the surface of the beads in comparison to the corresponding fractions found in bile. The composition of the adsorbed film is approximately 1 cholesterol: 2 phospholipid: 3 bile salt molecules. The performed complex of lipase, colipase, and bile lipids behaves as an entity which determines lipase adsorption. The modification of the interface quality of a lipid substrate by a detergent is not perse the reason for the lack of lipase adsorption. A model is proposed according to which lipolysis under physiological conditions would occur in two steps requiring two cofactors. Colipase would be necessary for the formation of the lipase-bile lipoprotein complex, and bile lipids would be required to direct the adsorption of this lipolytic entity toward the emulsified substrate.
TL;DR: The results suggest that a correlation may exist between lipase formation and alkane utilization and Pseudomonas aeruginosa and A. lwoffi and other bacteria degraded alkanes they exhibited substantial lipase activity.
Abstract: Acinetobacter lwoffi strain O(16), a facultative psychrophile, can grow on crude oil, hexadecane, octadecane, and most alkanes when tested at 20 but not at 30 degrees C. Growth occurred on a few alkanes at 30 degrees C but after a longer lag than at 20 degrees C. Cells grown on alkanes as sole carbon sources had high levels of cell-bound lipase. In contrast, previous work has shown that those grown on complex medium produced cell-free lipase and those grown on defined medium without alkanes produced little or no lipase. Low concentrations of the detergent Triton X-100 caused the liberation of most of the lipase activity of alkane-grown cells and increased total lipase activity. When ethanol and hexadecane were both present in a mineral medium, diauxic growth occurred; until the ethanol was completely used up, hexadecane was not utilized, and the lipase activity was very low. When growth on hexadecane began, lipase activity increased, reaching a level 50- to 100-fold higher than that of cells growing on ethanol. A similar pattern of lipase formation and hexadecane utilization was observed with Pseudomonas aeruginosa. Whenever A. lwoffi and other bacteria degraded alkanes they exhibited substantial lipase activity. Not all bacteria that produced lipase, however, could attack alkanes. Bacteria that could not produce lipase did not attack alkanes. The results suggest that a correlation may exist between lipase formation and alkane utilization.
TL;DR: The patterns of enzyme-activity change was remarkably similar in all the sites studied, although the growth of the tissues proceeded non-uniformly, and changes in enzyme activity were related to other metabolic changes in adipose tissue and with the known changes in plasma insulin concentrations occurring during development.
Abstract: The lipoprotein lipase (clearing-factor lipase) activity of the white adipose tissue from rats aged between 1 and 145 days was determined. Five adipose-tissue sites (epididymal, uterine, subcutaneous, perirenal and intramuscular) together with serum concentrations of triacylglycerol, cholesterol and glucose were studied. The pattern of enzyme-activity change was remarkably similar in all the sites studied, although the growth of the tissues proceeded non-uniformly. After a peak of activity early in suckling, lipoprotein lipase activity fell to low values by 20 days of age. At weaning (21 days) the activity increased sharply and within 5 days high values were regained. The serum triacylglycerol and cholesterol concentrations were low at birth and reached peaks of concentration coincidentally with the minima of white-adipose-tissue lipoprotein lipase activities, seen late in suckling. The changes in enzyme activity were related to other metabolic changes in adipose tissue and with the known changes in plasma insulin concentrations occurring during development.
TL;DR: It is postulated that lipase, although critical for fungal nutrition in vitro, is unlikely to be of importance in vivo, and skin surface lipids are therefore probably not relevant to the pathogenesis of pityriasis versicolor.
Patent•
06 Jan 1978TL;DR: In this article, a method for the detection of free glycerol or a fatty acid ester of glycerols in aqueous liquids such as blood serum is described, which comprises the steps of I: contacting in the presence of an electron acceptor (a) a sample to be assayed and (b) a novel reagent composition comprising 1. lipase which hydrolyzes triglycerides to glycerolis; 2. glyceriol kinase; 3. adenosine triphosphate; 4. α-glycerophosphate oxidase to
Abstract: A method is described for the assay of glycerol (as either free glycerol or a fatty acid ester of glycerol) in aqueous liquids such as blood serum. The method comprises the steps of I: contacting in the presence of an electron acceptor (a) a sample to be assayed and (b) a novel reagent composition comprising 1. optionally, a lipase which hydrolyzes triglycerides to glycerol; 2. glycerol kinase; 3. adenosine triphosphate; 4. α-glycerophosphate oxidase to produce a detectable change in the presence of triglyceride or a general positive sample; and II: detecting the occurrence of said detectable change. The lipase is included when fatty acid esters of glycerol (i.e., triglycerides) are to be detected. Free glycerol from whatever source can be detected with a composition comprising 2-4 above. According to a preferred embodiment, the electron acceptor is oxygen and the reagent composition also includes a hydrogen peroxide indicator composition, i.e., reagents which interact with hydrogen peroxide to produce a detectable product. The method can be used for assay of ATP. The method and reagent composition for performing the disclosed assays can be incorporated into a matrix of absorbent material.
TL;DR: The data suggest that the lingual serous glands of rat tongue are similar to other exocrine glands such as pancreas and parotid gland in the subcellular localization of secretory enzymes and mechanisms of enzyme secretion.
Abstract: The lingual serous glands of rat tongue secrete a potent lipase that acts in the stomach in which it initiates the digestion of dietary fat. The subcellular localization of the enzyme and factors affecting its activity and secretion were studied in adult male Sprague-Dawley rats. In a fraction rich in secretory granules, 42% of the lipase content of lingual serous glands was recovered after fractionation of homogenates of discontinuous gradients of urografin in 0.3 M sucrose. Lipase secretion was stimulated by isoprenaline: 2 h after isoprenaline administration, the lipase content of lingual serous glands was 73 +/- 5% lower than that of the control group. Accumulation of lipase began 8 h after the injection, reaching 57 +/- 7% of the initial level of the control group after 25 h. Bilateral resection of the glosso-pharyngeal nerves or bilateral sympathectomy led to a 40--50% decrease of enzyme activity in 7 days. Enzyme activity was markedly affected by the fat content of the diet. Feeding a high-fat diet (22% corn oil) for a period of 2 wk led to a 45% increase in the lipase content of lingual serous glands. The exponential rise in the lipase activity of the lingual serous glands immediately after birth could be related to the high-fat content of rat milk. The data suggest that the lingual serous glands are similar to other exocrine glands such as pancreas and parotid gland in the subcellular localization of secretory enzymes and mechanisms of enzyme secretion.
TL;DR: The interaction of porcine pancreatic lipase and colipase was studied during gel filtration in columns eluted with a variety of buffers and the relevance of the high affinity complex to the lipase-colipase .
TL;DR: The enzyme showed positional specificity for the fatty acid moieties located at the primary positions of sn-glycerol, and 1,3-Diacyl Glycerol was hydrolyzed at greater than twice the rate of the corresponding 1,2(2,3)-isomer.
TL;DR: Over-all quantitative estimations emphasized the dominant role of monoacylglycerol lipase over the other two enzymes in the hydrolysis of Monoacyl glycerol in acetone-ether preparations from fasted rats.
TL;DR: Evaluation of dose-response relationships showed that in duodenal ulcer patients the secretion of gastric lipase and pepsin is more sensitive to pentagastrin stimulation than that of hydrogen ions.
Abstract: Secretion patterns of gastric lipase and pepsin were studied in duodenal ulcer patients before and after vagotomy and in healthy subjects following continuous administration of pentagastrin in graded doses. The lipase output increased in response to pentagastrin stimulation in similar fashion as that of pepsin. The output of the two enzymes were correlated with each other and with hydrogen ion output. Evaluation of dose-response relationships showed that in duodenal ulcer patients the secretion of gastric lipase and pepsin is more sensitive to pentagastrin stimulation than that of hydrogen ions.
TL;DR: It was found that the phospholipase A1 and triglyceridase activities of lipoprotein lipase similarly depend on the presence of apolipoprotein C-II.
TL;DR: A simultaneous decrease in lipoprotein lipase activity releasable with heparin in a subsequent incubation indicates two distinct effects of insulin on the enzyme in this system.
TL;DR: It is concluded that cholesteryl ester content of chylomicrons under these conditions neither affects their protein composition nor has a major effect on their rate of reaction with lipoprotein lipase.
TL;DR: The pKa values of the two histidines in colipase are determined and a tentative assignment of the pK, values of specific amino acid residues in proteins, such as histidine, tyrosines and lysines is made.
TL;DR: In this paper, partial lipase hydrolysis and interesterification with excess glycerol have been investigated and the effects on the chemical and physical properties of palm oil has been investigated.
Abstract: Palm oil has been treated by partial lipase hydrolysis and by interesterification with excess glycerol and the effects on the chemical and physical properties have been investigated Lipase hydrolysis preferentially removes unsaturated acids and the neutral glycerides remaining after removal of the free fatty acids therefore have an increased solids content at 20°C Both differential scanning calorimetry (dsc) and X-ray examination show that the crystalline phases present above 20°C are more heterogeneous after lipase treatment Interesterification results in a mixture of tri- and diglycerides with an increased solids content at 20°C and a marked tendency to form β phase crystals Some potential practical applications are discussed
TL;DR: The essential role played by colipase confirms that the primary step in the inhibition is an interaction of lipase with bile salt containing micelles, and appears that the requirements oflipase towards specific substrates and inhibitors are very similar.