Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Colipases”

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

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

At least 253 records · Page 14Linked to original sources
PubMed2000

Characterization of turkey pancreatic lipase.

Turkey pancreatic lipase (TPL) was purified from delipidated pancreases. Pure TPL (glycerol ester hydrolase, EC 3.1.1.3) was obtained after ammonium sulfate fractionation, Sephacryl S-200 gel filtration, anion exchange chromatography (DEAE-Sepharose) and size exclusion column using high performance liquid chromatography system (HPLC). The pure lipase, which is not a glycoprotein, was presented as a monomer having a molecular mass of about 45 kDa. The lipase activity was maximal at pH 8.5 and 37 degrees C. TPL hydrolyses the long chains triacylglycerols more efficiently than the short ones. A specific activity of 4300 U/mg was measured on triolein as substrate at 37 degrees C and at pH 8.5 in the presence of colipase and 4 mM NaTDC. This enzyme presents the interfacial activation when using tripropionin as substrate. TPL was inactivated when the enzyme was incubated at 65 degrees C or at pH less than 5. Natural detergent (NaTDC), synthetic detergent (Tween-20) or amphipatic protein (beta-lactoglobulin A) act as potent inhibitors of TPL activity. To restore the lipase activity inhibited by NaTDC, colipase should be added to the hydrolysis system. When lipase is inhibited by synthetic detergent or protein, simultaneous addition of colipase and NaTDC was required to restore the TPL activity. The first 22 N-terminal amino acid residues were sequenced. This sequence was similar to those of mammal's pancreatic lipases. The biochemical properties of pancreatic lipase isolated from bird are similar to those of mammals.

Amino Acid Sequence↗
PubMed2003

In vitro lipolysis by human pancreatic lipase is specifically abolished by its inactive forms.

In human adults, the enzymatic hydrolysis of dietary fat along the digestive tract is sequentially catalyzed by two main enzymes, human gastric lipase (HGL) and human pancreatic lipase (HPL). Both a chemically inhibited form of HPL as well as an inactive HPL mutant with a glycine residue substituted for its catalytic serine were found to be strong inactivators of HPL activity. In the presence of bile salts, this inhibition was clearly due to competition for colipase. We established that the chemically inhibited HPL, probably in its open conformation, had a much greater affinity for colipase than the closed native form of HPL. These inhibitory effects are quite substantial, because a 0.2-M excess of the chemically inhibited HPL form relative to HPL reduced the catalytic lipolytic activity by 50% in the presence of an equimolar amount of colipase.

Anthracenes↗
PubMed2001

Decreased postnatal survival and altered body weight regulation in procolipase-deficient mice.

In vitro, pancreatic triglyceride lipase requires colipase to restore activity in the presence of inhibitors, like bile acids. Presumably, colipase performs the same function in vivo, but little data supports that notion. Other studies suggest that colipase or its proform, procolipase, may have additional functions in appetite regulation or in fat digestion during the newborn period when pancreatic triglyceride lipase is not expressed. To identify the physiological role of procolipase, we created a mouse model of procolipase deficiency. The Clps-/- mice appeared normal at birth, but unexpectedly 60% died within the first 2 weeks of life. The survivors had fat malabsorption as newborns and as adults, but only when fed a high fat diet. On a low fat diet, the Clps-/- mice did not have steatorrhea. The Clps-/- pups had impaired weight gain and weighed 30% less than Clps+/+ or Clps+/- littermates. After weaning, the Clps-/- mice had normal rate of weight gain, but they maintained a reduced body weight compared with normal littermates even on a low fat diet. Despite the reduced body weight, the Clps-/- mice had a normal body temperature. To maintain their weight gain in the presence of steatorrhea, the Clps-/- mice had hyperphagia on a high fat diet. Clps-/- mice had normal intake on a low fat diet. We conclude that, in addition to its critical role in fat digestion, procolipase has essential functions in postnatal development and in regulating body weight set point.

Age Factors↗
PubMed2000

Fats infused intraduodenally affect the postprandial secretion of the exocrine pancreas and the plasma concentration of cholecystokinin but not of peptide YY in growing pigs.

In pigs, the spontaneous secretion of the exocrine pancreas and the release of cholecystokinin (CCK) and peptide YY (PYY) after intraduodenal infusion of fully saturated synthetic fats differing in chain length was studied. Growing pigs (n = 6) were prepared with pancreatic duct catheters, duodenal T-cannulas and catheters placed in the jugular vein. The pigs were fed 2 g/100 g body twice daily. Beginning with the morning feeding, a medium-chain triglyceride (MCT: glycerol tricaprylate), a long-chain triglyceride (LCT: glycerol tristearate) or saline was infused at a rate of 0.1 g/100 g body. Pancreatic juice was collected, beginning 1 h preprandially until 3 h postprandially. Blood samples were obtained 15 min preprandially and 15, 45, 90 and 150 min postprandially. The infusion of MCT evoked a change in the trend of the curve for the volume of secretion of pancreatic juice, lipase and colipase concentrations and outputs. The trend of the curve did not change over time for CCK and PYY. Differences between the trends of the curves for the saline and MCT treatment were observed for volume of secretion, protein output, lipase content and output, trypsin and colipase output. Differences in the trends of the curves between MCT and LCT were obtained for the outputs of protein, lipase and colipase. Plasma CCK levels were lower as a result of the MCT treatment compared with the saline and LCT treatments. The results suggest an immediate, distinguished response of the porcine exocrine pancreas to fats differing in chain length.

Animals↗
PubMed1998

Stability of porcine and microbial lipases to conditions that approximate the small intestine of young birds.

In vitro experiments were conducted to study the stability of lipase activities from bacterial, fungal, and animal sources under conditions that approximate the small intestine. In the first experiment, the effects of preincubation with trypsin (500, 1,000, and 2,000 U/mL), chymotrypsin (200, 400, and 800 U/mL), and trypsin plus chymotrypsin (TC; 2,000 U/mL trypsin + 800 U/inL chymotrypsin) for 30 min at 40 C, on lipase activities from sources of Pseudomonas spp. (PL1, PL2), Chromobacterium viscosum (CVL), and Aspergillus niger (ANL) were determined. None of the enzymes were inhibited by trypsin. The chymotrypsin decreased the activity of all of the lipases. The TC had no additional negative effect on the activities of PL1 and PL2; however, ANL and CVL activities were further decreased relative to the chymotrypsin only treatment. In the second study, the effects of Na taurodeoxycholate (0.1 to 16 mM) on the activities of PL1, PL2, CVL, ANL, and crude porcine lipase (CPL) at 23 and 40 C were evaluated. At 23 C, in order of potency, Na taurodeoxycholate inhibited the activities of ANL, CPL, and CVL. At this temperature, Na taurodeoxycholate did not inhibit PL1 and PL2. An increase in the temperature to 40 C increased the activity of all of the enzymes tested. At 40 C, Na taurodeoxycholate had similar effects on lipase activities; however, higher Na taurodeoxycholate levels were required to inhibit ANL activity, and only a partial inhibition of CPL occurred. At 23 C, porcine colipase restored the activity of CPL but had no effect on ANL and CVL in the presence of inhibitory levels of Na taurodeoxycholate. At 40 C, porcine colipase had no effect on Na taurodeoxycholate inhibition of lipase activity. The results of this study indicate that PL is more stable than CVL and ANL, and that colipase addition has no beneficial effects on microbial lipase activities under conditions that approximate the avian small intestine.

Animals↗
PubMed1987

Effects of inverse changes in dietary lipid and carbohydrate on the synthesis of some pancreatic secretory proteins.

The effect of ingesting isocaloric and isonitrogenous diets with increasing amounts of lipid (0-30%) and consequently decreasing amounts of carbohydrates (68.7-1.25%) on the exocrine pancreas was studied in adult male Wistar rats. Pancreatic contents of chymotrypsin, lipase and colipase activity, as well as synthesis of amylase, lipase, procarboxypeptidases and individual serine proteases were examined. Lipid-free diets and diets containing 1% lipid were found to have little effect on pancreatic proteins as compared with lipid-rich diets where two distinct patterns of response were observed. Ingestion of diets containing 3-20% lipid resulted in a progressive increase in the activity of lipase, colipase and chymotrypsin up to 2-fold in the first case and 1.6-fold in the two other cases when animals were fed the 20% fat diet. Under the latter conditions, the relative synthesis of secretory proteins, as expressed as percentage of the radioactivity incorporated into individual proteins compared to that incorporated into the total mixture of exocrine proteins, was unchanged for procarboxypeptidases, whereas it was stimulated for lipase (2-fold) and serine proteases (1.6-fold). Amylase relative synthesis progressively decreased as the lipid content of diets increased. Consumption of hyperlipidic diets containing 25% and 30% fat resulted in a further enhancement in the activity of lipase and colipase in the gland in contrast with chymotrypsin activity which was unchanged as compared to the control diet (3% lipid). As far as biosynthesis was concerned, a plateau in the relative synthesis of lipase and serine protease was reached. Amylase relative synthesis further decreased down to 2.2-fold when rats were fed the 30% fat-rich diet whereas that of procarboxypeptidases was markedly increased (about 1.7-fold). Absolute rates of synthesis of total pancreatic secretory proteins, as expressed with regard to the DNA content of the tissue, indicated that biosynthesis of all secretory pancreatic proteins was stimulated by hyperlipidic diets (at least 2-fold with the 30% lipid diet). Consequently, when such an increase was taken into consideration, the absolute synthesis of amylase was found to be unchanged throughout the dietary manipulations, whereas that of lipase, procarboxypeptidases and serine proteases were stimulated by 4.0-fold, 3.4-fold and 3.2-fold, respectively.

Animals↗
PubMed1986

Fat necrosis in human acute pancreatitis. An immunohistological study.

Localization of phospholipase A2, lipase and colipase immunoreactivity were studied in paraffin embedded tissue sections. The samples were taken from the pancreas of 12 patients suffering from acute haemorrhagic necrotizing pancreatitis, and from diseased adipose tissue of 7 patients suffering from traumatic mammary fat necrosis. Peroxidase-antiperoxidase immunohistology revealed consistent positive reaction against phospholipase A2, lipase and colipase at the border of fat necrosis in pancreatic interlobular adipose tissue and in peripancreatic, mesenterial and retroperitoneal fat. The fat necroses of the breast were devoid of reaction. The results support the idea that in addition to lipase colipase and phospholipase A2 participate in the development of fat necrosis in acute pancreatitis. Pancreatic lipolytic enzymes are not present in the adipose tissue in mammary fat necrosis.

Adipose Tissue↗
PubMed1994

Rat pancreatic lipase and two related proteins: enzymatic properties and mRNA expression during development.

We report the cDNA sequences of rat colipase, rat pancreatic lipase (rPL), and a rat pancreatic lipase-related protein (rPLRP). Comparison to the human PLRP cDNA suggests that the isolated clone encodes rPLRP-2. Both cDNA and a third cDNA encoding rPLRP-1 are secreted from Sf9 cells infected with recombinant baculovirus. rPL and rPLRP-2 hydrolyze triolein, 8.0 and 4.4 mumol.min-1.microgram-1, respectively. They are inhibited by bile salts, and activity is restored by (pro)colipase. PLRP-1 has barely detectable activity against triolein, even with (pro)colipase present. The pattern of mRNA expression during development in the rat reveals that all mRNA are low in the fetal rat pancreas. Both PLRP mRNA rise just before birth to a maximum 12 h after birth. They fall to low levels in the adult. In contrast, the PL mRNA is low at birth and rises rapidly during the suckling-weanling transition. In conclusion, the rat has at least three genes encoding different lipases, and these related genes have separate regulatory controls.

Aging↗
PubMed1986

Assays of serum lipase: analytical and clinical considerations.

We evaluated three commercially available methods for determining lipase (EC 3.1.1.3) in serum--the Du Pont aca, Boehringer Mannheim Diagnostics (BMD), and Kodak Ektachem (EK) procedures--for their analytical properties and diagnostic efficiencies. Titrimetry was used as the comparative method. The BMD and EK methods showed better agreement with the titrimetric method, owing to the presence of the necessary cofactor, colipase, in their reagents. Colipase also increased the analytical sensitivity of the BMD and EK procedures as compared with the aca method. Determinations of serum lipase, by all methods, had a clinical sensitivity in excess of 80% for acute pancreatitis; the specificity of the lipase test was about 60%, or twice that of serum amylase. Serum lipase determinations with the current, simpler technology are superior to total amylase in the diagnosis of patients with acute pancreatitis. When a colipase-supplemented method is used, a serum lipase value greater than 10-fold the upper reference limit appears to be pathognomonic for acute pancreatitis or inflammation of organs close to the pancreas.

Acute Disease↗
PubMed1989

Lipase activity measured in serum by a continuous-monitoring pH-Stat technique--an update.

Using recent knowledge regarding the roles of colipase, bile acids, Ca2+, and emulsifiers, we optimized a previously published pH-Stat method for lipase (EC 3.1.1.3) activity measurements. The recommended assay conditions are: olive oil/triolein, 100 mL/L; sodium glycocholate, 35 mmol/L; Ca2+, 8.5 mmol/L; and colipase, 6.0 mg/L. The sample volume is 0.10 mL, the reaction pH 9.0, the temperature 30 degrees C, and the concentration of titrant 15 mmol/L. Hydroxypropyl methylcellulose, 20 g/L, replaces acacia as emulsifier to avoid inhibition by excess Ca2+. The standard curve is linear to greater than 4566 U/L. The reference interval with olive oil as substrate is 30-235 U/L. Lipase activities with triolein substrate are 9.9% greater than with olive oil. Interference by pancreatic carboxylesterase (EC 3.1.1.1) activity is inhibited by incubating the sample with diisopropylfluorophosphate. Results correlate well with those by the optimized SingleVial method of Boehringer Mannheim Diagnostics (r = 0.997) and the immunochemical assay of Beckman Instruments, Inc. (r = 0.995). Correlation with the aca method (E.I. DuPont de Nemours & Company) is less satisfactory (r = 0.892), probably owing to lack of colipase in the latter method.

Adult↗
PubMed1983

Studies on the detergent inhibition of pancreatic lipase activity.

Pancreatic lipase requires colipase, a protein cofactor, to counteract the in vitro inhibition by bile salt. Lipase activity is inhibited by nonsteroidic detergents regardless of their charge and structure. Detergent-inhibited lipase is reactivated by colipase but in all cases activation is limited to a narrow range of detergent concentration. Complementary studies on the bile salt and detergent effect on lipase activity and on interfacial tension at the substrate-water interface show that inhibition is not related to the interfacial surface tension. It is hypothesized that absorption of amphiphilic compounds to the substrate surface modifies the distribution of the enzyme between the lipid surface and the aqueous phase. The activity of detergent-inhibited lipase is fully restored by adding bile salt to the reaction system. Bile salt might play a critical role during in vivo lipolysis by desorbing surface-active substances from the lipid-water interface thus allowing lipase and colipase to interact with substrate.

Animals↗
PubMed1994

A surface loop covering the active site of human pancreatic lipase influences interfacial activation and lipid binding.

The distinguishing feature of lipases is their increased activity at an oil-water interface, termed interfacial activation. X-ray crystallography of lipases suggested a mechanism for interfacial activation by revealing conformational changes in several surface loops that cover the active site. In one conformation, these loops prevented substrate from entering the active site, and, in the other conformation, movement of the loops opened the active site. We tested the role of the major surface loop, the lid domain, in human pancreatic lipase (hPL) function by creating deletions in this region and expressing the mutant proteins in baculovirus-infected insect cells. the mutants were tested for activity against tributyrin and triolein, colipase interaction, interfacial activation, and binding to tributyrin. The purified mutants had decreased activity against both tributyrin and triolein compared to wild-type hPL and did not show a preference for either substrate. Although colipase was required for maximum activity in the presence of bile salts, the mutants had significant activity against tributyrin, but not triolein, in the absence of colipase. Both mutants were active against monomers of tributyrin demonstrating that they did not require an interface for activity. Finally, both mutants had decreased binding to tributyrin particles. These results suggest that the lid domain in hPL mediates interfacial activation and influences interfacial binding.

Animals↗
PubMed1980

Mechanism of action of milk lipoprotein lipase at substrate interfaces: effects of apolipoproteins.

The mechanism of action of bovine milk lipoprotein lipase was studied by using a monomolecular film of 1,2-didecanoylglycerol. The apparent rate of hydrolysis of diglyceride increased with increasing surface pressures above 12 mN/m; the enzyme was inactive at pressures less than 12 mN/m. We have measured the effects of four plasma apolipoproteins (apoC-II, apoC-III, apo-I, and apoE), bovine serum albumin, porcine pancreatic colipase, heparin, and NaCl on the kinetics of lipid hydrolysis. At a surface pressure of 15 mN/m, all of the proteins, with the exception of colipase, gave increased enzyme activity compared to lipase alone; apoC-II gave maximal activation. At 25 mN/m, apoC-II at concentrations of less than 0.25 microgram/mL showed a specific activation, whereas the other proteins had no effect. Heparin activated at both high and low surface pressures; NaCl had little or no effect in this system. At a higher concentration of apoC-II (0.50 microgram/mL), the apoprotein inhibited the enzyme. The addition of apoC-III, apoA-I, or apoE (final concentration 0.25 microgram/mL), but not albumin or colipase, to apoC-II (0.25 microgram/mL) caused an increase in surface pressure of 5-6 mN/m and an apparent rate which was less than half that found for lipase alone, suggesting that all of the apoproteins inhibit the apoC-II specific activation.

Animals↗
PubMed2004

In vitro studies of the effects of HAART drugs and excipients on activity of digestive enzymes.

PURPOSE: Side effects of diarrhea and steatorrhea diminish the therapeutic value of highly active antiretroviral therapy (HAART). We report in vitro studies of the effect of HAART drugs on the activity of pancrelipase, trypsin, and enterokinase and restoration of activity by subsequent addition of excess pancrelipase or colipase. METHODS: Commercial formulations of sixteen HAART drug formulations with solvent and four excipients were mixed with substrate. Activity of pancrelipase was recorded after addition of the enzyme; restoration of activity was monitored after addition of excess pancrelipase or colipase to the reaction mixture. RESULTS: Five protease inhibitors (Agenerase solution, Agenerase capsules, Norvir, Viracept, Kaletra, and Fortovase) and the excipient TPGS (d-alpha-tocopheryl polyethylene glycol 1000 succinate) inhibited lipase significantly at or below physiological concentrations. Neither nucleoside reverse transcriptase inhibitors nor non-nucleoside reverse transcriptase inhibitors showed significant lipase inhibition at physiological levels. Addition of excess pancrelipase to the medium completely reversed inhibition by Agenerase, Fortovase, Norvir, and TPGS and reactivated lipase; it diminished inhibition by Kaletra and Viracept but did not completely restore activity. Addition of colipase reversed inhibition by Agenerase solution, Agenerase capsules, and TPGS; inhibition by Kaletra and Fortovase recovered slightly. No compounds tested inhibited trypsin or enterokinase. CONCLUSIONS: These results justify evaluating protocols involving coadministration of buffered pancrelipase with protease inhibitors to reduce or eliminate diarrhea and steatorrhea in individuals being treated for HIV.

Antiretroviral Therapy, Highly Active↗
PubMed1992

Gastric and pancreatic enzyme activities and their relationship with some gut regulatory peptides during postnatal development and weaning in calves.

Changes in the activities of three gastric and nine pancreatic enzymes plus colipase were determined during postnatal development and weaning in calves. In calves exclusively milk-fed for 2, 7, 28, 56, 70 and 119 d, the enzyme activities per kilogram of empty live weight increased with age for chymotrypsin, elastase, carboxypeptidases A and B, ribonuclease and alpha-amylase, decreased for chymosin, lysozyme and colipase but showed no change in the case of pepsin, trypsin, lipase and phospholipase A2 compared with animals at birth. The greatest increase was that in alpha-amylase activity (about 50-fold between d 2 and 119). In calves weaned between d 28 and 56, all the activities were higher than in milk-fed animals, except that of chymosin (which was slightly lower) and that of colipase (which did not change). At 119 d of age, chymotrypsin, carboxypeptidase A, alpha-amylase and lipase were 1.6- to fourfold higher in ruminants than in preruminants. Thus, most enzyme activities were modified first by colostrum and milk intake, and again upon weaning by development of the forestomachs and ingestion of solid food. These ontogenic patterns might be under the control of many gut regulatory peptides, the plasma concentrations of which changed simultaneously. Some gastric and pancreatic enzymes were correlated to plasma concentrations of these gut regulatory peptides.

Abomasum↗
PubMed1996

Digestive lipases of the newborn ferret: compensatory role of milk bile salt-dependent lipase.

The amount of mRNA hybridizing to bile salt-dependent lipase and to colipase-dependent lipase probes as well as their translation into active proteins were quantified in the adult and newborn pancreas and lactating mammary gland from the ferret, a species whose milk, similar to that of the human, has bile salt-dependent lipase. The concentration of colipase-dependent lipase mRNA correlated with the amount of activity found in the adult and newborn pancreas, whereas neither mRNA nor activity of this enzyme was detected in the kit pancreas or in the lactating mammary gland. These data indicate that colipase-dependent lipase is actually expressed in adult pancreas and might represent the main lipolytic system in the adult. mRNA hybridizing to the bile salt-dependent lipase probe used in this study were detected in adult and in newborn ferret pancreas as well as in lactating mammary gland. However, the bile salt-dependent lipase activity expressed in the newborn pancreas was very low when compared with the activity expressed either in the mammary gland or in the adult pancreas. These data argue for a compensatory role of milk bile salt-dependent lipase in lipid digestion in the newborn. The hydrolysis of dietary fat might be initiated by preduodenal lipase, the activity of which is only two times lower in the gastric mucosa of the newborn than in the adult ferret. The high concentration of mRNA hybridizing to the bile salt-dependent lipase probe associated with a very poor bile salt-dependent lipase activity and protein suggests either that these mRNA are very unstable or that they are poorly translated into an active pancreatic bile salt-dependent lipase.

Animals↗
PubMed1997

Development of digestive enzymes in pigs with emphasis on lipolytic activity in the stomach and pancreas.

The effect of age and weaning on the activities of digestive enzymes with emphasis on the lipolytic enzymes before and after weaning was investigated. The activities of amylase, chymotrypsin, trypsin, carboxyl ester hydrolase, pancreatic lipase, and colipase in pancreatic tissue and the activity of gastric lipase in the cardiac mucosa of the stomach in 45 pigs were response variables. The activity of trypsin was not affected by weaning and the rate of increase was similar during the whole experiment. The activities of chymotrypsin and amylase decreased at weaning (P < .05). After weaning the activity of chymotrypsin increased more slowly than before weaning (P < .001), whereas the rate of increase of amylase activity remained unchanged. Lipase, colipase, and carboxyl ester hydrolase activities decreased at weaning (P < .001), whereas gastric lipase activity increased at weaning (P < .01). The development of lipase, colipase, and carboxyl ester hydrolase activity decreased postweaning (P < .01), whereas gastric lipase activity increased before weaning and remained constant after weaning. Pancreatic lipase had a considerably higher capacity for hydrolyzing tributyrin, and the total activity of pancreatic lipase was up to 600 times higher than that of gastric lipase. The lipolytic enzymes displayed a non-parallel pattern of development, and we suggest that this reflects the importance of these enzymes during the suckling and postweaning phases, respectively. However, the significance of gastric lipase for the digestion of fat in pigs remains to be elucidated.

Aging↗
PubMed1991

Pancreatic lipolytic enzymes in human duodenal contents. Radioimmunoassay compared with enzyme activity.

The total pancreatic lipolytic capacity was determined in duodenal contents in healthy humans 10-120 min after a liquid test meal, by estimating the amount of pancreatic lipase, colipase, carboxyl ester lipase, and phospholipase A2 by means of radioimmunoassays and enzymatic assays. The molar concentrations of the different proteins were of the same order of magnitude. The relative specific activity (enzyme activity/milligram immunoreactive protein expressed as a percentage of the specific activity of the respective pure protein) amounted to 75-120% for lipase, 45-80% for colipase, 30-70% for carboxyl ester lipase, and 45-120% for phospholipase A2. These varied, and sometimes low values can be explained by the fact that the enzymes are inhibited or partly inactivated in the duodenal contents by surface denaturation, in which cases the products are still immunoreactive. Also, the proforms of colipase and phospholipase A2 may not always be completely activated. Furthermore, the specific activities of the pure enzymes (and thus the relative specific activities) are related to the methods used, which are not specific enough to distinguish completely the three enzymes and the cofactor in duodenal contents.

Adult↗