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At least 307 records · Page 17Linked to original sources
PubMed1994

Cholesteryl esters on the body surfaces of the camel tick, Hyalomma dromedarii (Koch, 1844) and the brown dog tick, Rhipicephalus sanguineus (Latreille, 1806).

Cholesteryl esters were found to constitute a major component of the lipids coating the body cuticle of females of the camel tick, Hyalomma dromedarii and the brown dog tick, Rhipicephalus sanguineus. One or more cholesteryl esters, alone or in combination, have been shown to serve as the mounting sex pheromone of several species of ixodid ticks. Consequently, knowledge of these compounds is important for an understanding of the mating behavior of these ticks. Based on thin layer chromatography, cholesterol and cholesteryl esters were the most abundant neutral lipids found on the body surfaces of fed females of these two species. Analysis using HPLC demonstrated significant quantities of the following compounds, tentatively identified as cholesteryl esters (expressed in micrograms per female equivalent), in H. dromedarii: Cholesteryl acetate 18.2; cholesteryl laurate, 6.8; cholesteryl linoleate, 24.8; cholesteryl oleate, 12.9; cholesteryl palmitate, 0.3; and cholesteryl stearate 1.7. In contrast, the same method revealed only 3 cholesteryl esters in extracts of females of R. sanguineus: Cholesteryl acetate, 2.0; cholesteryl linoleate, 8.5; and cholesteryl oleate, 3.0. In both species, two unidentified peaks, with the spectral characteristics of cholesteryl esters, were also observed. Identification of the cholesteryl esters was confirmed: by (1) positive bioassay results with conspecific (H. dromedarii) males and heterospecific (Dermacentor variabilis) males; (2) similarity of ultraviolet spectra between identified sample peaks and authentic standards; and (3) demonstration of cholesterol and the corresponding free fatty acid following enzymatic digestion of each of the HPLC-separated fractions containing the different cholesteryl esters. Comparisons with the cholesteryl ester composition of the mounting sex pheromone of other metastriate Ixodidae are discussed. These findings, along with studies reported previously, suggest that differences in the mounting sex pheromones of ixodid ticks are an important factor in minimizing heterospecific matings in nature.

Animals↗
PubMed1992

On coenzyme Q orientation in membranes: a linear dichroism study of ubiquinones in a model bilayer.

A general approach is developed to interpret linear dichroism (LD) spectra of ubiquinones (Qn) in host bilayers. Information is reported in terms of guest-host mutual orientation and localization. The overall orientational anisotropy of guest ubiquinone molecules is described by a basic set of limiting orientation/localization modes. Assignments of the UV transitions of the ubiquinone chromophore were obtained by the liquid crystal-linear dichroism technique and molecular orbital (CNDO/S) calculations. The LD spectra of Qn in the bilayers provided by the lyotropic nematic mesophase exhibited by water solutions of potassium laurate and decanol were interpreted on the basis of the above assignments. The resulting experimental evidence showed a multisite distribution in the host bilayer for the aromatic heads of all the investigated Qn derivatives except Q0. The orientational distribution suggested by the LD spectra fits the solubilization model recently proposed by G. Lenaz [J. Membrane Biol. (1988) 104:193-209] for ubiquinone in lipid membranes. Within this model Qn molecules are located in the midplane and their headgroups oscillate transversally across the membrane. Q0 instead has a single site location, close to the polar bilayer interface. Experimental evidence that the headgroup carbonyls tend to grasp the polar interface of the host bilayer was also obtained. Orientation and location distributions of Qn guest molecules are therefore likely to result from the tendency of their aromatic heads to grasp the polar heads of the host bilayer and from the concurrent tendency of their chains to settle into the hydrocarbon host interior.

Cell Membrane↗
PubMed1977

Expression of esterases during ontogenesis of the flour beetle Tribolium castaneum (Tenebrionidae; Coleoptera).

Two electrophoretically fast-migrating, nonspecific esterases were detected in two strains of the flour beetle Tribolium castaneum and designated F (fast) and S (slow) according to their relative migration distances. Both isozymes are associated with the alimentary canal and display ontogenetic changes. Their activity is very low in the egg stage, increases in the larva, and declines dramatically in the pharate pupa and pupa. The overall activity in the pupal stage is low, yet increases gradually throughout this period. In the adult, the activity of the esterases rises sharply. The larval and adult F and S isozymes were found to hydrolyze alpha- and beta-naphthylacetate and alpha-naphthylpropionate with almost equal capacity. alpha-Naphthyl laurate was cleaved by the F enzyme of both larvae and adults. The F and S were insensitive to inhibitors of arylesterases and cholinesterases and were markedly inhibited by the organophosphate di-isopropylphosphorofluoridate (DFP) and could be classified as carboxylesterases. Differential sensitivities of larval and adult esterases to urea and heat treatment as well as to DFP may indicate the expression of different genes during metamorphosis.

Animals↗
PubMed1975

A GLC method for estimation of chlorophenoxyisobutyric acid in plasma. Pharmacokinetics of a single oral dose of clofibrate in man.

A GLC method has been developed to measure chlorophenoxyisobutyric acid in plasma after benzol extraction and transformation to its methyl ester, using methyl laurate as the internal standard. Plasma free fatty acids did not interfere with the analysis, but it could not be employed in the presence of salicylates. The method has been employed to study the pharmacokinetics of chlorophenoxyisobutyric acid in man after oral ingestion of a single dose of clofibrate.

Adult↗
PubMed1993

Probing the fatty acid binding site of beta-lactoglobulins.

The interactions of fatty acids with porcine and bovine beta-lactoglobulins were measured using tryptophan fluorescence enhancement. In the case of bovine beta-lactoglobulin, the apparent binding constants for most of the saturated and unsaturated fatty acids were in the range of 10(-7) M at neutral pH. Bovine beta-lactoglobulin displays only one high affinity binding site for palmitate with an apparent dissociation constant of 1 x 10(-7) M. The strength of the binding was decreasing in the following way: palmitate > stearate > myristate > arachidonate > laurate. Caprylic and capric acids are not bound at all. The affinity of beta-lactoglobulin for palmitate decreased as the pH of the incubation medium was lowered and BLG/palmitate complex was not observed at pH's lower than 4.5. Surprisingly, chemically modified bovine beta-lactoglobulin and porcine beta-lactoglobulin did not bind fatty acids in the applied conditions.

Amino Acid Sequence↗
PubMed1975

Purification and properties of aortic cholesteryl ester hydrolase.

The enzyme(s) present in acetonedried powder of rat and rabbit aortas, which catalyzes the synthesis and hydrolysis of cholesteryl ester, was purified partially by acid precipitation, acetone fractionation, O-(diethylaminoethyl) cellulose chromatography, and Sephadex G-100 filtration. The synthetic activity was purified by 120-fold (rat) and 140-fold (rabbit). Purification of hydrolytic activity was 90-fold (rat) and 103-fold (rabbit). Cholesteryl ester hydrolase activity was separated from nonspecific esterase by column chromatography. Both synthetic and the hydrolytic activities are apparently the functions of one enzyme. The mol wt of the enzyme was estimated to be 140,000 dalton as determined by Sephadex G-200 gel filtration. The extracts of the acetone-dried powders of aortas of both species contained an inhibitor of synthetic activity. The inhibitor was nondialyzable and was precipitated at pH 5.7. Both activities were found to be fairly nonspecifc with regard to sterol and fatty acids. With oleic acid, the relative rates of sterol ester synthesis were: cholesterol, 100; cholestanol, 94; desmosterol, 35; coprostanol, 24; ergosterol, 20; and beta-sitosterol, 19. Epicholesterol was not esterified. Oleic acid was most active in cholesteryl ester synthesis, the relative rates being: oleic greater than linoleic greater than arachidonic greater than palmitic greater than stearic greater than butyric. The rate of hydrolysis was maximum with cholesteryl linoleate followed by oleate, linolenate, palmitate, stearate, and laurate in decreasing order.

Acetone↗
PubMed1981

Omega- and (omega-1)-hydroxylation of 1-dodecanol by frog liver microsomes.

Frog liver microsomes catalyzed the hydroxylation of 1-dodecanol into the corresponding omega- and (omega-1)-hydroxy derivatives. The hydroxylation rate for 1-dodecanol was much lower than that for lauric acid. Both NADPH and O2 were required for hydroxylation activity. NADH had no effect on the hydroxylation. The hydroxylating system was inhibited 49% by CO at a CO:O2 ratio of 4.0. The formation of omega-hydroxydodecanol was more sharply inhibited by CO than was the formation of (omega-1)-hydroxydodecanol, implying that more than one cytochrome P-450 was involved in the hydroxylation of 1-dodecanol and that CO has a higher affinity for the P-450 catalyzing the omega-hydroxylation. The formation of laurate during the incubation of 1-dodecanol with frog liver microsomes suggests that a fatty alcohol oxidation system is also present in the microsomes. NAD+ was the most effective cofactor for the oxidation of 1-dodecanol and NADP+ had a little effect. Pyrazole (an inhibitor of alcohol dehydrogenase) had a slight inhibitory effect on the oxidation and sodium azide (an inhibitor of catalase) had no effect.

Animals↗
PubMed1987

Hydroxylation of fatty acids and alcohols by hepatic microsomal cytochrome P-450 system from the Mongolian gerbil.

The liver microsomes of the Mongolian gerbil Meriones unguiculatus catalyzed the hydroxylation of various saturated fatty acids (C8-c18), alcohols (C12 and C16) and hydrocarbon (C12) to the corresponding omega- and (omega-1)-hydroxy derivatives. Lauric acid was hydroxylated most effectively among saturated fatty acids and the order of activity as hydroxylation substrates was C12 greater than C14 greater than C13 greater than C16 greater than C10 greater than C18 greater than C8. The specific activity of laurate hydroxylation (5.99 nmol/mg microsomal protein/min) in gerbil liver microsomes was higher than that observed in other species. 1-Dodecanol was also hydroxylated very effectively (4.58 nmol/mg microsomal protein/min) by gerbil liver microsomes, but in general the hydroxylation rates for fatty alcohols were much lower than those for the corresponding acids. It was found from both inhibitor and cofactor studies that the enzyme catalyzing the hydroxylation of fatty acids and alcohols in the liver microsomes of the Mongolian gerbil was a typical cytochrome P-450-linked monooxygenase, and at least two different cytochrome P-450 species were involved in the hydroxylation.

Animals↗
PubMed1995

A microsomal membrane component associated with iron reduction in NADPH-supported lipid peroxidation.

This study was conducted to determine whether a factor responsible for reduced nicotinamide adenine dinucleotide phosphate (NADPH)-supported lipid peroxidation in rat liver microsomes is involved in iron reduction by cooperation with NADPH-cytochrome P450 reductase. Under anaerobic conditions, NADPH-dependent reduction of ferric pyrophosphate in microsomes was not dependent on cytochrome P450 levels and was not inhibited by carbon monoxide (CO). All of the iron complexes with chelators such as adenosine 5'-diphosphate, pyrophosphate, nitrilotriacetate, oxalate or citrate were reduced in microsomes, although in the reconstituted system containing purified NADPH-cytochrome P450 reductase little or no iron reduction was found. A cytochrome P450-free fraction from a cholate-solubilized preparation of microsomes after passage through a laurate sepharose column was required for reduction of iron pyrophosphate in the reconstituted system leading to lipid peroxidation. The iron reduction was not inhibited by CO and was destroyed by heat treatment or trypsin digestion of the fraction. All iron complexes were reduced in the presence of the fraction, using a reducing equivalent of NADPH via NADPH-cytochrome P450 reductase. The results indicate that a heat-labile component, which is probably a protein distinct from cytochrome P450, is associated with iron reduction responsible for lipid peroxidation in microsomes.

Animals↗
PubMed1990

Fatty acid hydroxylase system in the Japanese harvest mouse, Micromys minutus.

Liver microsomes of the Japanese harvest mouse (Micromys minutus), which is the smallest known mammal among rodents, catalyze the hydroxylation of various fatty acids (C8 to C18) to the corresponding omega-hydroxy and (omega-1)-hydroxy derivatives. Although laurate is most effectively hydroxylated among saturated fatty acids by liver microsomes of other species, harvest mouse liver microsomes most effectively catalyze the hydroxylation of decanoate. From inhibitor and cofactor studies, and from the substrate specificity for hydroxylation, it was concluded that omega- and (omega-1)-hydroxylation of fatty acids are catalyzed by different cytochrome P-450 species in the liver microsomes of the harvest mouse.

Animals↗
PubMed2002

Effect of vehicles and enhancers on the in vitro permeation of melatonin through hairless mouse skin.

The effects of vehicles and penetration enhancers on the in vitro permeation of melatonin through dorsal hairless mouse skin were investigated. Propylene glycol laurate (PGL), isopropyl myristate (IPM), propylene glycol monolaurate (PGML) and propylene glycol monocaprylate (PGMC) showed high permeation fluxes and PGL, PGML and PGMC decreased lag time significantly. In both of the binary co-solvents of diethylene glycol monoethyl ether (DGME)-PGL and DGME-IPM, the highest fluxes were achieved at 20% of DGME, which were 10.5 +/- 1.5 and 9.1 +/- 2.4 microg/cm2/h, respectively. Among fatty acids used as a permeation enhancer, capric acid and oleic acid in DGME-PGL (80:20 v/v) showed relatively high enhancing effects. Capric acid also shortened the lag time of melatonin from 2.4 +/- 0.7 to 1.3 +/- 0.2 h. Oleic acid, however, failed to shorten the lag time. Therefore, for effective solution formulations in terms of permeation flux and lag time, capric acid-containing DGME-PGL (80:20 v/v) could be used to enhance the skin permeation of melatonin.

Administration, Cutaneous↗
PubMedDate not supplied

Induction and inactivation of a cytochrome P450 confering herbicide resistance in wheat seedlings.

Cytochrome P450-dependent enzymes from wheat catalyze the oxidation of endogenous compounds (lauric and oleic acids) and of several herbicides (diclofop, chlortoluron, bentazon). Treatment of wheat seedlings with the safener, naphthalic anhydride and with phenobarbital increases dramatically several P450-dependent enzyme activities including diclofop and lauric acid hydroxylation. The parallel induction of lauric acid (omega-1)-hydroxylase and diclofop hydroxylase activities suggests that both compounds proceeds from the same or very similar forms of P450. To test whether either one or multiple P450 forms are involved in these oxidations, we have designed selective irreversible inhibitors of lauric acid (omega-1)-hydroxylase. Results of in vivo and in vitro experiments with acetylenic analogs of lauric acid (10- and 11-dodecynoic acids) strongly suggest that a single P450 catalyzes both laurate and diclofop hydroxylation. Treatment of wheat seedlings with these acetylenes results in a strong inhibition of the in vivo metabolism of diclofop although oxidation of chlortoluron and bentazon are not affected. Our results suggest that at least three distinct P450 forms are involved in the detoxification process of the three herbicides. Interestingly, we also demonstrate that herbicides themselves are potent inducers of the amount of total P450 and laurate/diclofop hydroxylase activies. This increased capacity of wheat to detoxify the herbicide through the induction of P450 enzymes seems to be for a large extend the mechanism which confers a tolerance on various herbicides.

Benzothiadiazines↗
PubMed2006

Chlorobium chlorochromatii sp. nov., a symbiotic green sulfur bacterium isolated from the phototrophic consortium "Chlorochromatium aggregatum".

A symbiotic green sulfur bacterium, strain CaD, was isolated from an enrichment culture of the phototrophic consortium "Chlorochromatium aggregatum". The capability of the epibiont to grow in pure culture indicates that it is not obligately symbiotic. Cells are Gram-negative, nonmotile, rod-shaped and contain chlorosomes. Strain CaD is obligately anaerobic and photolithoautotrophic, using sulfide as electron donor. Acetate and peptone are photoassimilated in the presence of sulfide and hydrogencarbonate. Photosynthetic pigments contain bacteriochlorophylls a and c, and gamma-carotene and OH-gamma-carotene glucoside laurate as the dominant carotenoids. In cells from pure cultures, chlorosomes are equally distributed along the inner face of the cytoplasmic membrane. In contrast, the distribution of the chlorosomes in symbiotic epibiont cells is uneven, with chlorosomes being entirely absent at the site of attachment to the central bacterium. The symbiotic epibiont cells display a conspicuous additional layered structure at the attachment site. The G + C content of genomic DNA of strain CaD is 46.7 mol%. On the basis of 16S rRNA sequence comparison, the strain is distantly related to Chlorobium species within the green sulfur bacteria phylum (<or=94.6% sequence homology). The novel isolate is therefore described as a novel species within the genus Chlorobium, Chlorobium chlorochromatii.

Acetic Acid↗
PubMed2003

Inter-species comparisons of hepatic cytochrome P450 enzyme levels in male ruminants.

Our current knowledge about the biotransformation enzymes in wild ruminants is limited. The present study aimed to compare basic levels and specific activities of cytochrome P450 isoforms (CYP1A, 2A, 2B, 2C, 2D, 2E, 3A, 4A) in males of red deer ( Cervus elaphus), fallow deer ( Dama dama), roe deer ( Capreolus capreolus) and mouflon ( Ovis musimon). The proteins from the major cytochrome P450 (CYP) subfamilies were detected in all ruminant species by Western blotting, using polyclonal antibodies raised against rat or human CYP enzymes. The immunochemical data seem to suggest that humans and wild ruminants share some similar hepatic CYP enzymes corresponding to members of subfamilies 2 and 3; ruminant liver samples also contained two proteins cross-reacting with anti-rat CYP1A antibodies. High activities of CYP1A enzymes found in liver microsomes of male fallow deer and roe deer are indicative of increased susceptibility of these species towards promutagens that are metabolically activated by these CYPs. On the other hand, low activities of CYP1A-dependent alkoxyresorufin O-dealkylase activities were detected in male mouflons. Oxidative metabolism of testosterone was significantly higher in wild ruminants than the values previously reported from bulls. Androstene-3,17-dione and 6beta-hydroxytestosterone were the most important products of testosterone oxidation in liver microsomes of all the ruminant species under study. The highest CYP3A-dependent testosterone 6beta-hydroxylase activity was found in mouflons and fallow deer. A different pattern of CYP activities towards testosterone was found in roe deer, which showed high activities of testosterone 2beta-hydroxylase and lower production of androstene-3,17-dione. An increased activity of CYP4A-dependent laurate 12-hydroxylase found in roe deer and mouflons might indicate a higher metabolic turnover of fatty acids. The data on CYP activities indicated that high metabolic rates of steroids, fatty acids, and xenobiotics may occur in male wild ruminants. The highest hepatic activities specific for CYP3A, CYP2C, CYP2D, and CYP2E enzymes were found in mouflon, suggesting that this species has the highest biotransformation capacity.

Animals↗
PubMed1999

Independent production of two molecular forms of a recombinant Rhizopus oryzae lipase by KEX2-engineered strains of Saccharomyces cerevisiae.

A mixture of rProROL having the full-length prosequence (97 amino acids) for a recombinant lipase of Rhizopus oryzae (rROL) and r28ROL having 28 amino acids of the same prosequence has been produced as active forms by Saccharomyces cerevisiae [Takahashi et al. (1998) J Ferment Bioeng 86: 164-168]. However, the separation of rProROL and r28ROL has not been successful due to their identical behavior on column chromatographs, presumably because of the similarity of their surface properties. The independent production of two different molecular forms of rROL was carried out using KEX2-engineered strains of S. cerevisiae, since r28ROL was predicted to be a product from rProROL by a Kex2-like protease. rProROL was successfully obtained by expression of the ROL gene in the S. cerevisiae kex2 strain in which the KEX2 gene encoding Kex2p was disrupted, while r28ROL was obtained by co-expression of the gene (KEX2 delta 613) encoding the soluble form of the C-terminal truncated Kex2 protease (sKex2p). The specific lipase activities of rProROL and r28ROL were 92.9 U/mg and 140 U/mg, respectively. rProROL was stable at pH 2.2-8.0, and showed the optimal reaction temperature to be 30-35 degrees C with a T50 of 55 degrees C (T50 is the temperature resulting in 50% loss of activity). The values for r28ROL were pH 3.0-10.0, 25-30 degrees C, and 40 degrees C, respectively. rProROL was an N-linked glycosylated form, but r28ROL was not. The enhanced thermostability of rProROL did not seem to be due to the N-linked glycosylation, as judged by the results of the Endo H treatment. rProROL had the highest esterase activity toward p-nitrophenyl laurate (C12), whereas r28ROL had the highest esterase activity toward p-nitrophenyl caprylate (C8) and stearate (C18). These results suggest that the distinct properties of these two forms of lipase are caused by the different length of the ROL prosequence.

Bacterial Proteins↗
PubMed2003

A new oral testosterone undecanoate formulation.

Testosterone undecanoate has been available on the market for more than 20 years. This testosterone ester is used worldwide for oral treatment of male hypogonadism. So far, testosterone undecanoate has been dissolved in oleic acid, leading to inconvenient storage conditions. It will now be available in a new formulation with castor oil and propylene glycol laurate instead of oleic acid, thus improving storage conditions markedly (stable at room temperature for approximately 3 years). Pharmacokinetic and pharmacodynamic studies have demonstrated bioequivalence of the old and the new formulation of testosterone undecanoate. Therefore, the results of studies that were performed with the old formulation can be transferred to the clinical use of the new formulation. Controlled studies have shown its efficacy in the treatment of symptoms associated with reduced serum testosterone levels. In these cases testosterone undecanoate improves bone mineral density, quality of life, muscle mass, libido and mood. Further studies will help evaluate the efficacy and safety of the new formulation in the treatment of elderly men with late-onset hypogonadism.

Administration, Oral↗
PubMed2006

A thermostable lipolytic enzyme from a thermophilic Bacillus sp.: purification and characterization.

A thermophilic Bacillus sp. was isolated that secreted an extracellular, thermostable lipolytic enzyme. The enzyme was purified to 58 folds with a specific activity of 9730 units/mg of protein and yield of 10% activity by ammonium sulphate precipitation, Phenyl Sepharose chromatography, gel-permeation followed by Q Sepharose chromatography. The relative molecular mass of the protein was determined to be 61 kDa by SDS-PAGE and approximately 60 kDa by gel permeation chromatography. The enzyme showed optimal activity at 60-65 ( composite function)C and retained 100% activity after incubation at 60 ( composite function)C and pH 8.0 for 1 h. The optimum pH was determined to be 8.5. It exhibited 50% of its original activity after 65 min incubation at 70 ( composite function)C and 23 min incubation at 80 ( composite function)C. Catalytic function of lipase was activated by Mg(++) (10 mM), while mercury (10 mM) inactivated the enzyme completely. No effect on enzyme activity was observed with trypsin and chymotrypsin treatment, while 50% inhibition was observed with thermolysin. It was demonstrated that PMSF, SDS, DTT, EDTA, DEPC, betaME (100 mM each) and eserine (10 mM) inhibited the activity of the lipolytic enzyme. With p-nitrophenyl laurate as a substrate, the enzyme exhibited a K ( m ) and V (max) of 0.5 mM and 0.139 microM/min/ml. The enzyme showed preference for short chain triacylglycerol and hydrolyzes triolein at all positions. In contrast to other thermostable Bacillus lipases, this enzyme has very low content of hydrophobic amino acids (22.58 %). Immunological studies showed that the active site and antigen-binding site of enzyme do not overlap.

Bacterial Proteins↗
PubMed2002

Distinction between esterases and lipases: a kinetic study with vinyl esters and TAG.

The better to characterize enzymes hydrolyzing carboxyl ester bonds (carboxyl ester hydrolases), we have compared the kinetic behavior of various lipases and esterases against solutions and emulsions of vinyl esters and TAG. Short-chain vinyl esters are hydrolyzed at comparable rates by esterases and lipases and have higher limits of solubility in water than corresponding TAG. Therefore, they are suited to study the influence of the physical state of the substrate on carboxyl ester hydrolase activity within a large concentration range. Enzymes used in this study are TAG lipases from microorganisms, lipases from human and guinea pig pancreas, pig liver esterase, and acetylcholinesterase. This study also includes cutinase, a fungal enzyme that displays functional properties between esterases and lipases. Esterases display maximal activity against solutions of short-chain vinyl esters (vinyl acetate, vinyl propionate, and vinyl butyrate) and TAG (triacetin, tripropionin, and tributyrin). Half-maximal activity is reached at ester concentrations far below the solubility limit. The transition from solution to emulsion at substrate concentrations exceeding the solubility limit has no effect on esterase activity. Lipases are active on solutions of short-chain vinyl esters and TAG but, in contrast to esterases, they all display maximal activity against emulsified substrates and half-maximal activity is reached at substrate concentrations near the solubility limit of the esters. The kinetics of hydrolysis of soluble substrates by lipases are either hyperbolic or deviate from the Michaelis-Menten model and show no or weak interfacial activation. The presence of molecular aggregates in solutions of short-chain substrates, as evidenced by a spectral dye method, likely accounts for the activity of lipases against soluble esters. Unlike esterases, lipases hydrolyze emulsions of water-insoluble medium- and long-chain vinyl esters and TAG such as vinyl laurate, trioctanoin, and olive oil. In conclusion, comparisons of the kinetic behavior of carboxyl ester hydrolases against solutions and emulsions of vinyl esters and TAG allows the distinction between lipases and esterases. In this respect, it clearly appears that guinea pig pancreatic lipase and cutinase are unambiguously classified as lipases.

Acetylcholinesterase↗