Showing papers on "Lipase published in 1972"
TL;DR: The enzyme had the characteristics of a lipoprotein lipase, i.e. its activity against emulsified long chain triglyceride was stimulated more than 20-fold by addition of suitable amounts of serum to the assay system and the activity was almost completely inhibited by 1 m NaCl.
163 citations
TL;DR: The enzymatic hydrolysis in vitro of the esters of methanol, ethylene glycol, glycerol, erythritol, pentaerythredol, adonitol, sorbitol, and sucrose in which all alcohol groups were esterified with oleic acid was studied.
148 citations
TL;DR: In many muscles from both vertebrates and invertebrates the activity of glycerol kinase is similar to that of lipase, however, in some insect flight muscles the activity is much greater than that oflipase, which suggests a different role for glycerl kinase in these muscles.
Abstract: 1. The activities of tri-, di- and mono-glyceride lipase and carnitine palmitoyltransferase were measured in homogenates of a variety of muscles. These activities were used to estimate the rate of utilization of glycerides and fatty acids by muscle. In muscles whose estimated rates of fat utilization can be compared with rates calculated for the intact muscle from such information as O2 uptake, there is reasonable agreement between the estimated and calculated rates. 2. In all muscles investigated the maximum rates of hydrolysis of glycerides increase in the order triglyceride, diglyceride, monoglyceride. The activity of diglyceride lipase is highest in the flight muscles of insects such as the locust, waterbug and some moths and is lowest in the flight muscles of flies, bees and the wasp. These results are consistent with the utilization of diglyceride as a fuel for some insect flight muscles. 3. In many muscles from both vertebrates and invertebrates the activity of glycerol kinase is similar to that of lipase. It is concluded that in these muscles the metabolic role of glycerol kinase is the removal of glycerol produced during lipolysis. However, in some insect flight muscles the activity of glycerol kinase is much greater than that of lipase, which suggests a different role for glycerol kinase in these muscles.
129 citations
TL;DR: Porcine pancreatic lipase has been purified to homogeneity as determined with analytical polyacrylamide gels and both isoenzymes of lipase were shown to be glycoproteins containing 3.8 moles of mannose and N-acetylglucosamine per mole of enzyme.
96 citations
TL;DR: A principal function of the monoglycerid hydrolase activity of pre-heparin plasma, and released from the liver by heparin, may be to hydrolyse the 2-monoglyceride residue, which is the major product of lipoprotein lipase activity against triglyceride substrates.
83 citations
TL;DR: The specific properties of lipase were confirmed when it was observed that the enzyme was not inhibited by E 600 solutions in the absence of bile salts, and concentrated DFP solutions were found to react with a single, non-essential tyrosine residue in native lipase.
75 citations
TL;DR: The molecular weight of co-lipase determined with several techniques is in the order of 10 000 with no significant difference between the value based on amino acid analysis and the values based on other methods indicating that the molecule is essentially free of non-protein components.
64 citations
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TL;DR: The existence of a lipase in pancreatic juice can be easily demonstrated by activity determinations, either directly or after fractionation of the enzymes by ion exchange chromatography.
Abstract: Publisher Summary Lipases are currently classified among hydrolases. They participate in transfer reactions in which molecules other than water can act as the acceptor for fatty acyl radicals. No bonds other than carboxyl ester bonds have ever been found to be hydrolyzed by lipases. The mammalian lipases are classified into three groups—the lipases discharged into the digestive tract by specialized organs, tissue lipases, and milk lipases. Among the digestive lipases, the enzyme synthesized by the acinar cells of the pancreas plays an essential role during the intraluminar digestion of dietary triglycerides because of its unusually high molecular activity. Mammalian liapses are also present in a number of tissues or organs of mammals such as heart, brain, muscle, arteries, kidney, adipose tissue, and serum. Lipases are widely distributed among bacteria, yeasts, and fungi. Most of them are discharged through the external membrane into the culture medium (exocellular lipases). The existence of a lipase in pancreatic juice can be easily demonstrated by activity determinations, either directly or after fractionation of the enzymes by ion exchange chromatography. Like the other pancreatic enzymes, lipase is stored in zymogen granules before extrusion into the secretory ducts.
58 citations
TL;DR: From the observed effect of colipase on maximum rate of hydrolysis of emulsified triglycerides, it is suggested that the cofactor might be involved in the rate-limiting step of lipolysis.
57 citations
TL;DR: A wide range of flavor profiles can be produced via control of enzyme, fat and processing prior to and subsequent to enzyme modification as mentioned in this paper, including margarine, imitation dairy products, confections and prepared foods.
Abstract: Technology has been developed for the production of flavor systems via controlled enzyme modification of fats. Lipases and esterases from various sources are used. Fats modified include milk fat and meat fats. A wide range of flavor profiles can be produced via control of enzyme, fat and processing prior to and subsequent to enzyme modification. Applications for the flavor systems include margarine, imitation dairy products, confections and prepared foods.
57 citations
TL;DR: A rapid and sensitive spectrophotometric assay for free fatty acids using rhodamine 6G dye base in benzene as a fatty acid indicator is described, finding negligible to moderate interference by methyl stearate, phosphatidylcholine, cholesterol, partially purified spinach galactolipids, and spinach subchloroplast particle pigments.
TL;DR: Under the conditions of homogenization used, approximately one-third of the total hormone-sensitive lipase activity was associated with the fat cake floated to the top of a homogenate by low speed centrifugation, although this value remains uncertain in view of technical problems faced in assaying lipase tightly bound to fat.
TL;DR: The action of indole acetic acid and the nitrogenous compound in inducing lipase activity in isolated bran appears to require the prior action of a cytokinin and some other unidentified factor.
TL;DR: Post-heparin phospholipase activity is reduced by 80% in the hepatectomized rat, and the lipase originates entirely in extrahepatic tissues, suggesting that these two activities must be different enzymes.
TL;DR: In this paper, tannic substances were isolated from dehydrated lucerne meal and it was found that they contained free gallic acid, gallotannins and flavanols.
Abstract: Tannic substances were isolated from dehydrated lucerne meal and it was found that they contained free gallic acid, gallotannins and flavanols. In the procedure for their isolation, cation and anion exchange resins, Amberlite IR-120 and Amberlite IR-45, were used. The isolated tannin was tested as an inhibitor of tryptic digestion of casein, L-amylolytic digestion of starch and lipase enzymes. In in vitro studies it was found that the isolated tannin has a high inhibitory action on digestive enzymes.
TL;DR: The mould enzyme is less active than the pancreatic enzyme on short-chain triglycerides and, for the same activity on emulsified particles, its action on micelles is stronger, while the lipase from Rhizopus arrhizus is not activated by bile salts.
TL;DR: The enzyme composition of human pancreatic juice has been studied by immunological techniques, using non-activated and activated juice using antisera were prepared with activated and nonactivated pancreatic juices as discussed by the authors.
Abstract: 1
The enzyme composition of human pancreatic juice has been studied by immunological techniques, using non-activated and activated juice.
2
Antisera were prepared with activated and non-activated pancreatic juice. Same samples of antisera were adsorbed with human serum. Immunoelectrophoresis was carried out at pH 8.6 and disc immunoelectrophoresis at pH 8.9 and 5.0. Gel-diffusion media contained benzamidine, to prevent zymogen activation. Precipitation lines were characterized by activating the zymogens on the plates with trypsin, and identifying the enzymes produced using specific synthetic substrates.
3
Immunoelectrophoresis showed 15–20 antigenic constituents. Although disc immunoelectrophoresis gave slightly different results, those were consistent with the results of immunoelectrophoresis.
4
The following active enzymes were identified and localized: α-amylase, lipase and carboxylester hydrolase, which is a lipolytic enzyme structurally and catalytically different from lipase.
5
Several zymogens were identified: two immunologically distinct trypsinogens, one procarboxypeptidase B, two forms of procarboxypeptidase A, which are immunologically identical, and two proelastases with some common antigenic determinants. After activation, both proelastases showed a weak but different degree of chymotryptic activity. Chymotrypsinogen was localized in two major anionic lines, and one, minor, cationic line. The possibility that one anionic immune precipitate represents a polymer is discussed. No chymotryptic activity was associated with procarboxypeptidase A.
6
Immunoelectrophoresis of activated pancreatic juice demonstrates electrophoretic and antigenic changes. Activation of one anionic trypsinogen gave rise to cationic trypsin, whereas after activation chymotrypsinogens and procarboxypeptidases A showed no important change.
TL;DR: An extremely rapid and sensitive assay for lipoprotein lipase activity, suitable for routine determinations, is described and based on trichloroacetic acid precipitation of unreacted substrate and measurement of (3)H-labeled glycerol.
TL;DR: Two pancreatic Lipases of different molecular weight were found in human pancreatic juice and the results suggest that the high molecular weight lipase exists as a low molecular weightlipase-phospholipid complex.
TL;DR: These data are compatible with the presence of a separate monoglyceridelipase not subject to kinase-mediated activation and having rather distinct properties from triglyceride lipase, however, until physical resolution of the two activities can be demonstrated this conclusion must remain tentative.
TL;DR: A thermophilic fungus which could produce a remarkable amount of thermostable, alkalistable and extracellular lipase has been isolated from the compost soil and it was identified as Humicola lanuginosa S-38.
Abstract: In view point of the basic research for the enzyme properties and the development of utilization of lipase, a thermophilic fungus which could produce a remarkable amount of thermostable, alkalistable and extracellular lipase has been isolated from the compost soil. The taxonomical characteristics of this thermophilic fungus were examined and it was identified as Humicola lanuginosa S-38.
TL;DR: To define the effect of age on triglyceride removal, PHLA was measured in a group of elderly subjects and a modification of the method of Fredrickson, Ono and Davis was used.
Abstract: A HEPARIN-activated clearing factor, lipoprotein lipase, is considered to have an important role in facilitating the removal of triglycerides from the circulation. The activity of this enzyme is detectable in plasma by an in vitro assay and is commonly called postheparin lipolytic activity (PHLA). Aging has been associated with prolonged alimentary lipemia.1 2 There is also a positive correlation between fasting plasma triglyceride concentrations and age.3 , 4 To define further the effect of age on triglyceride removal, PHLA was measured in a group of elderly subjects. Methods and Results PHLA was measured by a modification of the method of Fredrickson, Ono and Davis . . .
TL;DR: The minimum concentration of tetracyclines which produced detectable lipase inhibition in vitro was higher than the concentrations of tributyrin found in skin during the usual regimen of t Petracycline therapy in acne vulgaris, and muchHigher than the minimum bacteriostatic levels of tTrinityclines used on C acnes in vitro.
Abstract: The effect of various antibiotics on the hydrolytic activity of partially purified lipases from Corynebacterium acnes on tributyrin was studied by continuous potentiometric titration and by agar diffusion assays. Tetracycline hydrochloride, chlortetracycline hydrochloride, and demeclocycline hydrochloride inhibited C acnes lipase activity by 70% to 80% at concentrations of 500 μg/ml of substrate. Penicillin G potassium, erythromycin, neomycin sulfate, and streptomycin sulfate had no inhibitory effect on C acnes lipase activity. However, the minimum concentration of tetracyclines which produced detectable lipase inhibition in vitro was higher than the concentrations of tetracyclines found in skin during the usual regimen of tetracycline therapy in acne vulgaris, and much higher than the minimum bacteriostatic levels of tetracyclines used on C acnes in vitro.
TL;DR: In the chronic alcoholic insufficient production of pancreatic lipase seems to be responsible for the reversible abnormality in the intraluminal digestion of fat.
Abstract: Intraluminal fat digestion and absorption were evaluated in 15 chronic alcoholic and nine healthy volunteer males by aspiration of a standard meal from the jejunum. Intraluminal bile salts were present in normal concentrations and micellar solubilization of fatty acids and monoglycerides was within normal limits. Pancreatic lipase concentrations, however, were significantly lower in the alcoholic patients. As a consequence, hydrolysis of triglycerides was slower resulting in abnormally low concentrations of fatty acids and micellar lipids. Recovery of lipase production toward normal was demonstrated after four to six weeks by repeated intubation studies. Thus, in the chronic alcoholic insufficient production of pancreatic lipase seems to be responsible for the reversible abnormality in the intraluminal digestion of fat.
TL;DR: A highly specific and rapid assay for hormone-sensitive lipase activity of rat adipose tissue is described and employs emulsified 2,3-di-O-oleyl-[9,10-(3)H(2)]oleoyl glycerol as a substrate; it is very sensitive and is suitable for serial sampling.
TL;DR: The clearing-factor lipase activity of epididymal fat-pads decreased rapidly during 24h starvation in both lean and obese mice, but the activity in the obese mice remained higher than that in lean mice.
Abstract: 1. Clearing-factor lipase was assayed in acetone–ether-dried powders of heart and epididymal fat-pads of lean and genetically obese mice (ob/ob). In both tissues the enzyme activity in the adult was higher in the obese mice. 2. In heart the enzyme activity was unchanged from 8 to 48 weeks of age in lean mice, but in obese mice it increased between 8 and 12 weeks of age and remained elevated. 3. Starvation produced changes in the heart clearing-factor lipase activity in obese, but not lean, mice. 4. The clearing-factor lipase activity of epididymal fat-pads decreased rapidly during 24h starvation in both lean and obese mice, but the activity in the obese mice remained higher than that in lean mice. 5. Plasma triglyceride and cholesterol concentrations were determined in both lean and obese mice. Triglyceride concentrations were not greatly different, but the obese mice were hypercholesterolaemic. Plasma cholesterol concentrations were not correlated with changes in clearing-factor lipase activity.
TL;DR: The ability to solubilize NADPH-cytochrome c reductase was found only in those fractions containing protease activity and not in the fractions containing lipase activity.
TL;DR: From compost soil samples collected in the vicinity of Tokyo, a thermophilic fungus is isolated which could produce a remarkable amount of thermostable, alkalistable and ex tracellular lipase.
Abstract: gists5•`11) during the past decade, the production of lipase by thermophilic microorganisms has not been reported. The present investigation was undertaken as a basic research for the enzyme properties and development of utiliza tion of lipase. From compost soil samples collected in the vicinity of Tokyo, we have isolated a thermo philic fungus which could produce a remarkable amount of thermostable, alkalistable and ex tracellular lipase. The taxonomical character istics of this thermophilic fungus were examined and the fungus was identified as Humicola lanuginosa S-38. The thermophilic fungus was cultivated with aeration at 45°C for 80 hr on
TL;DR: Staphylococcus pyogenes PS54, the propagating strain of the group III staphylitiscal typing phage 54, manifests no lipase activity on egg yolk medium.
Abstract: Staphylococcus pyogenes PS54, the propagating strain of the group III staphylococcal typing phage 54, manifests no lipase activity on egg yolk medium. This strain was found to harbor at least two p...
TL;DR: The cultural conditions for the production of thermostable lipase by a thermophilic fungus Humicola lanuginosa S-38 were investigated in this paper, and the optimal cultural conditions to obtain the maximum yield of the lipase with a 600-liter stainless steel fermentor were as follows: optimal medium 2.0; rate of aeration 1/1 volume per volume of medium per minute.
Abstract: The cultural conditions for the production of thermostable lipase by a thermophilic fungus Humicola lanuginosa S-38 were investigated. The optimal cultural conditions to obtain the maximum yield of thermostable lipase with a 600-liter stainless steel fermentor were as follows: optimal medium-2.0% soluble starch, 5.0% corn steep liquor, 0.2% K2HPO4, 0.1% MgSO4•7H2O, 0.5% CaCO3, 0.5% soybean oil, 0.005% deforming agent (Adecanol LG-109); optimal fermentation conditions- temperature 45°C; rate of agitation 300rpm; initial pH 7.0; rate of aeration 1/1 volume per volume of medium per minute. The optimal pH of the crude lipase preparation for the hydrolysis of the polyvinyl alcohol-emulsified olive oil was 8.0 and the optimal temperature was 60°C. It retained 100% of activity with the heat treatment at 60°C for 2 hr, but at 70°C for 20min only 35% activity retained.