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At least 1,405 records · Page 78Linked to original sources
PubMed1990

Selective purification of sex-influenced esterase from rat serum by immunoaffinity chromatographies.

Sex-influenced esterase (ES-SI) is a female-specific serum esterase of rats. There are two alleles at the Es-Si locus, Es-Sia coding for ES-SI and Es-Sib, a silent allele. ES-SI was purified to electrophoretic homogeneity from the serum of adult female SI3 rats by a four-step purification. First, albumin was removed from the serum by Blue-Sepharose CL-6B affinity chromatography. Sera of rats carrying Es-Sia and Es-Sib were utilized to make two novel immunoaffinity columns. Rat anti-(ES-SI) alloantibody was obtained after the immunization of rats carrying Es-Sib with rat ES-SI-positive serum. ES-SI bound to the gel in this antibody-conjugated affinity chromatography. Simultaneously, rabbit anti-(rat serum protein lacking ES-SI) antibody was raised against ES-SI-negative rat serum and used to exclude other serum proteins. ES-SI was recovered in the flow-through fractions in this antibody-conjugated immunoaffinity chromatography, whereas the other serum proteins bound to the gel. ES-SI was selectively purified about 240-fold by combining these immunoaffinity chromatographies. This combination is a very powerful technique for purification of the protein. Finally, ES-SI was purified by preparative polyacrylamide gel electrophoresis after which it appeared as a single protein band (using silver staining) on SDS/polyacrylamide gel electrophoresis with a molecular mass of 72 kDa. In the ordinary estimation of enzyme purification, the purification of ES-SI was 30-fold at most, because the specific activity of the enzyme was calculated from the bulky esterase activity. However, ES-SI was selectively purified 2280-fold comparing its recovery to that of total protein. ES-SI exhibited a pI of 4.6 and optimum pH of 6.7. The activity of ES-SI was completely inhibited by diisopropyl fluorophosphate at 10 nM but not at all by eserine.

Animals↗
PubMed1995

Esterase comparison in neuroblastoma cells of human and rodent origin.

1. Activities of acetylcholinesterase (AChE), neuropathy target esterase (NTE), and carboxylesterase (CbxE) were compared in neuroblastoma cells of human origin (SH-SY5Y) and murine origin (NB41A3). 2. Mouse neuroblastoma cells had lower specific activities of NTE and CbxE than did human neuroblastoma cells; specific activities in the murine cells correlated with specific activities in mouse brain. 3. AChE activities in mouse and human neuroblastoma cells were considerably lower than AChE activities in mouse or hen brain. 4. Inhibition of esterases did not demonstrate interspecies differences for 12 of the 17 anti-esterase compounds tested with human and mouse neuroblastoma cells.

Acetylcholinesterase↗
PubMed1998

The usefulness of screening for chlamydial trachomatis infection with cervical mucus leukocyte esterase.

OBJECTIVE: To evaluate the ability of leukocyte esterase dipstick test (LET) performed in cervical mucus to predict direct immunofluorescent (DIF)-verified Chlamydia trachomatis (Ct) cervical infection. METHOD: Eighty women with inflammatory cervico-vaginal smear were submitted to both an endocervical smear, to verify Ct cervicitis by DIF technique; and a cervical mucus sample to perform LET. Results of LET and DIF were matched. RESULTS: Among 30 Chlamydial positive subjects, cervical mucus esterase test was positive in 28 (93.3%); while among 50 Chlamydial negative controls, esterase test was negative in 43 subject (86%). The sensitivity, specificity, positive and negative predictive values for LET were 93.3%, 86%, 80% and 95% respectively. CONCLUSION: Cervical mucus LET is a simple, cost effective screening test, with promising accuracy, for Ct cervical infection among women with inflammatory cervico-vaginal smears.

Biomarkers↗
PubMed1983

Quantitative variations in polymorphic types of human red cell esterase D.

Human red cell esterase D was analysed quantitatively in Japanese samples. Among the three esterase D phenotypes there was a significant difference in catalytic activity, with an approximate ratio of 7:5:3 for EsD 1, EsD 2-1 and EsD 2. With a few inter-type individuals, the distribution of their activity values was plotted in a tri-modal curve. These results suggest that the esterase D system in human red cells is qualitatively and even quantitatively controlled by genes.

Carboxylesterase↗
PubMed1993

Soluble and particulate organophosphorus neuropathy target esterase in brain and sciatic nerve of the hen, cat, rat, and chick.

Considerable evidence exists suggesting that the so-called neuropathy target esterase (NTE) is involved in the mechanisms responsible for organophosphorus-induced delayed polyneuropathy (OPIDP). Earlier studies in the adult hen, the habitually employed experimental model in OPIDP, have shown that most NTE activity in the brain is centered in particulate fractions, whereas approximately 50% of this activity in the sciatic nerve is encountered in soluble form, with the rest being particulate NTE. In the present work, we have studied the particulate and soluble fractional distribution of paraoxon-resistant phenylvalerate esterase activity (B activity), paraoxon- and mipafox-resistant phenylvalerate esterase activity (C activity), and NTE activity (B-C) according to ultracentrifugation criteria (100,000 g for 1 h). To this effect, two sensitive (adult hen and cat) and two scarcely sensitive (rat and chick) models were used. In all four experimental models, the distribution pattern was qualitatively similar: B activity and total NTE were much greater in brain (900-2,300 nmol/min/g of tissue) than in sciatic nerve (50-100 nmol/min/g of tissue). The proportion of soluble NTE in brain was very low (< 2%), whereas its presence in sciatic nerve was substantial (30-50%). The NTE/B ratio in brain was high for the particulate fraction (> 60%) and low in the soluble fraction (7-30%); in sciatic nerve the ratio was about 50% in both fractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed2005

Instant diagnosis of spontaneous bacterial peritonitis using leukocyte esterase reagent strips: Nephur-Test vs. MultistixSG.

BACKGROUND/AIM: Spontaneous bacterial peritonitis (SBP), defined by an ascites neutrophil count >250/mul, is a severe complication of cirrhosis and demands prompt diagnosis. Leukocyte esterase reagent strips can rapidly detect leukocytes in physiological fluids. We compared the performance of two leukocyte esterase reagent strips in the diagnosis of SBP. METHODS: Non-selected patients with cirrhosis and ascites were prospectively included in a Community Hospital. Manual ascites cytology, culture and BIOCHEMISTRY were compared with the Nephur-Test (read at 60 s: negative + 1 to + 3) and MultistixSG (read at 120 s: negative, trace, +1 to +3). Multiple investigators performed the tests with repeat readings by one nurse. RESULTS: Two hundred and forty five ascites fluid samples were obtained in 51 patients: 44% in conditions of SBP antibiotic prophylaxis, 64% in an ambulatory setting. Seventeen samples had an ascites polymorphonuclear count of > or =250/microl, associated with a positive ascites culture in seven, obtained in 12 patients (24%), 53% in an ambulatory setting. Sensitivity, specificity, and positive and negative predictive values were: Nephur-Test (88.2%, 99.6%, 93.8%, 99.1%); MultistixSG (64.7%, 99.6%, 91.7%, 97.4%). There was excellent agreement between the investigators and the nurse. CONCLUSIONS: Leukocyte esterase reagent strips may provide a rapid bedside diagnosis of SBP and thereby shorten time to appropriate management. The Nephur-Test appeared to out-perform MultistixSG. These tests might be particularly useful in ambulatory settings or whenever ascites fluid analysis is not rapidly available.

Adult↗
PubMed2001

High-level production of recombinant Aspergillus niger cinnamoyl esterase (FAEA) in the methylotrophic yeast Pichia pastoris.

The cDNA encoding Aspergillus niger cinnamoyl esterase (FAEA) with its native signal sequence was isolated by reverse transcriptase-polymerase chain reaction, sequenced, and expressed in Pichia pastoris. Secretion yields up to 300 mg l(-1) were obtained in buffered medium. The recombinant FAEA was purified to homogeneity using a one-step purification protocol and found to be identical to the native enzyme with respect to size, pI, immunoreactivity and N-terminal sequence. Specific activity, pH and temperature optimum, and kinetic parameters were also found similar to the native esterase. FAEA is thus the first fungal esterase efficiently produced using a heterologous system.

Aspergillus niger↗
PubMed1997

Fluorimetric determination of tissue distribution and differences between the activity of aspirin esterases I and II in mice and rats.

A modification of available fluorimetric methods, based on the native fluorescence of salicylic acid, has been used to assay the activity of aspirin esterases I and II in small amounts of several tissues from rats and mice. The results obtained showed that aspirin esterase I from mouse liver and kidney had the lowest activity and that the activity of aspirin esterase II from these organs was greater than that from the same organs from rats. Liver enzyme kinetics and tissue distribution in rats was shown to be similar to previous data obtained using a spectrophotometric method. This fluorimetric method, which is more sensitive and rapid than the spectrophotometric method, may be useful in studies on aspirin metabolism.

Adrenal Glands↗
PubMed1986

Transition state analogs as ligands for affinity purification of juvenile hormone esterase.

Insect juvenile hormones are metabolized in numerous species of caterpillars by low abundance, highly specific esterases. Because of their role in regulating and possibly disrupting juvenile hormone titer and thus insect metamorphosis, they are of interest to developmental biologists as well as scientists interested in selective insect control. However, the enzymes have defied attempts to purify and characterize them. Juvenile hormone esterase activity can be inhibited by a variety of 3-substituted 1,1,1-trifluoropropanone sulfides. These apparent transition state analogs were used as ligands and eluting agents to purify juvenile hormone esterase from four insect species from 500-fold to over 1000-fold in high yield. After elution from the affinity column, the enzymes were radiolabeled with paraoxon and analyzed by electrophoresis, and the results demonstrate a high degree of purity. Transition state analogs may be useful for the affinity purification of other enzymes.

Acetone↗
PubMed1997

Purification and characterization of a cephalosporin esterase from Rhodosporidium toruloides.

A novel cephalosporin esterase (EC 3.1.1.41) from Rhodosporidium toruloides was purified to gel electrophoretic homogeneity. The enzyme is a glycoprotein with a molecular mass of 80 kDa. Upon deglycosylation, several forms of the enzyme were observed with a molecular mass range between 60 and 66 kDa. The isoelectric point of the enzyme is approximately 5.6, with the pH optimum for activity occurring at 6.0. The optimal activity of the enzyme occurred at 25 degrees C, with the enzyme rapidly losing activity at temperatures above 25 degrees C. The enzyme deacetylated a variety of cephalosporin derivatives, including cephalosporin C; the Km for this substrate is 51.8 mM, and the Vmax is 7.9 mumol/min/mg. In addition to cephalosporins, the enzyme hydrolyzed short-chain p-nitrophenyl esters, with the activity decreasing with increasing ester chain length. The enzyme also has the ability to acetylate desacetyl cephalosporins in high yields under mild conditions in the presence of various acetyl donors. A comparison of the physical properties of the esterase with those of other well-characterized cephalosporin esterases indicates that the enzyme is unique in this class.

Amino Acid Sequence↗
PubMed1998

Balance of activities of alcohol acetyltransferase and esterase in Saccharomyces cerevisiae is important for production of isoamyl acetate.

Isoamyl acetate is synthesized from isoamyl alcohol and acetyl coenzyme A by alcohol acetyltransferase (AATFase) in Saccharomyces cerevisiae and is hydrolyzed by esterases at the same time. We hypothesized that the balance of both enzyme activities was important for optimum production of isoamyl acetate in sake brewing. To test this hypothesis, we constructed yeast strains with different numbers of copies of the AATFase gene (ATF1) and the isoamyl acetate-hydrolyzing esterase gene (IAH1) and used these strains in small-scale sake brewing. Fermentation profiles as well as components of the resulting sake were largely alike; however, the amount of isoamyl acetate in the sake increased with an increasing ratio of AATFase/Iah1p esterase activity. Therefore, we conclude that the balance of these two enzyme activities is important for isoamyl acetate accumulation in sake mash.

Acetyltransferases↗
PubMed1999

Regulation of the feruloyl esterase (faeA) gene from Aspergillus niger.

Feruloyl esterases can remove aromatic residues (e.g., ferulic acid) from plant cell wall polysaccharides (xylan, pectin) and are essential for complete degradation of these polysaccharides. Expression of the feruloyl esterase-encoding gene (faeA) from Aspergillus niger depends on D-xylose (expression is mediated by XlnR, the xylanolytic transcriptional activator) and on a second system that responds to aromatic compounds with a defined ring structure, such as ferulic acid and vanillic acid. Several compounds were tested, and all of the inducing compounds contained a benzene ring which had a methoxy group at C-3 and a hydroxy group at C-4 but was not substituted at C-5. Various aliphatic groups occurred at C-1. faeA expression in the presence of xylose or ferulic acid was repressed by glucose. faeA expression in the presence of ferulic acid and xylose was greater than faeA expression in the presence of either compound alone. The various inducing systems allow A. niger to produce feruloyl esterase not only during growth on xylan but also during growth on other ferulic acid-containing cell wall polysaccharides, such as pectin.

Aspergillus niger↗
PubMed2003

Purification and properties of a feruloyl esterase involved in lignocellulose degradation by Aureobasidium pullulans.

The lignocellulolytic fungus Aureobasidium pullulans NRRL Y 2311-1 produces feruloyl esterase activity when grown on birchwood xylan. Feruloyl esterase was purified from culture supernatant by ultrafiltration and anion-exchange, hydrophobic interaction, and gel filtration chromatography. The pure enzyme is a monomer with an estimated molecular mass of 210 kDa in both native and denatured forms and has an apparent degree of glycosylation of 48%. The enzyme has a pI of 6.5, and maximum activity is observed at pH 6.7 and 60 degrees C. Specific activities for methyl ferulate, methyl p-coumarate, methyl sinapate, and methyl caffeate are 21.6, 35.3, 12.9, and 30.4 micro mol/min/mg, respectively. The pure feruloyl esterase transforms both 2-O and 5-O arabinofuranosidase-linked ferulate equally well and also shows high activity on the substrates 4-O-trans-feruloyl-xylopyranoside, O-[5-O-[(E)-feruloyl]-alpha-L-arabinofuranosyl]-(1,3)-O-beta-D-xylopyranosyl-(1,4)-D-xylopyranose, and p-nitrophenyl-acetate but reveals only low activity on p-nitrophenyl-butyrate. The catalytic efficiency (k(cat)/K(m)) of the enzyme was highest on methyl p-coumarate of all the substrates tested. Sequencing revealed the following eight N-terminal amino acids: AVYTLDGD.

Ascomycota↗
PubMed1987

The need to screen all retinoblastoma patients for esterase D activity: detection of submicroscopic chromosome deletions.

Roughly 5% of all patients with retinoblastoma carry a constitutional chromosome deletion on the long arm of chromosome 13, which confers a prezygotic predisposition to tumour development. As offspring of deletion carriers have a 50% risk of inheriting the predisposition locus it is important to identify deletion carriers. The site of the esterase D gene to the often deleted region offers an objective means of deletion identification. The chromosomes of a patient with unilateral retinoblastoma, previously supposed to have a normal karyotype, were reexamined after the discovery that his red blood cells contained reduced activities of esterase D. A small sub-band deletion was found in chromosome region 13q14. These findings emphasise the importance of measurements of esterase D in all patients with retinoblastoma, even those with an apparently normal karyotype.

Carboxylesterase↗
PubMed1999

Adjuvant treatment of severe acute pancreatitis with C1 esterase inhibitor concentrate after haematopoietic stem cell transplantation.

BACKGROUND: With an incidence of 4%, acute pancreatitis is a common complication of bone marrow or peripheral haematopoietic stem cell transplantation, which contributes significantly to morbidity and mortality in these patients. In most cases, the pathogenesis of acute pancreatitis cannot be attributed to a single pathogenetic factor, as treatment toxicity, acute graft versus host disease, infection, and cholestasis may all contribute. Acute pancreatitis is characterised by inflammation and activation of digestive proenzymes leading to autodigestive destruction of the pancreas and systemic activation of protease cascades including the complement system. AIM: To describe the effects of human C1 esterase inhibitor in two children, who developed severe acute pancreatitis with considerable complement activation after allogeneic haematopoietic stem cell transplantation. METHODS: Both children showed clinical features resembling those observed in capillary leakage syndrome. In both patients, treatment with C1 esterase inhibitor concentrate contributed to a rapid clinical stabilisation. CONCLUSIONS: These observations strongly support the proposed pathophysiological concept that early treatment with C1 esterase inhibitor interferes with the activation of the complement system in acute pancreatitis. Inhibition of complement activation prevents its adverse effects on vascular function and permeability, and thus stabilises intravascular fluid status and prevents multiorgan failure in acute pancreatitis.

Acute Disease↗
PubMed2002

Spontaneous regression of acquired C1 esterase inhibitor deficiency associated with splenic marginal zone lymphoma presenting with recurrent angio-oedema.

A 52 year old woman with marginal zone lymphoma developed recurrent episodes of angio-oedema and was found to have C1 esterase inhibitor deficiency. She declined chemotherapy for the lymphoma. Fourteen months after her initial presentation she was found to be in partial remission, and this was confirmed by peripheral blood film and bone marrow examinations. This was associated with normalisation of C1 esterase inhibitor, C1q, and C4 values. Regression of acquired C1 esterase inhibitor deficiency associated with spontaneous partial remission of lymphoma has not been reported previously.

Angioedema↗
PubMed1984

Location of the retinoblastoma susceptibility gene(s) and the human esterase D locus.

Retinoblastoma occurs with increased frequency in children born with a deletion of the long arm of chromosome 13. Recent reviews have noted that the region 13q14 is consistently deleted in documented cases. Prometaphase and late prophase banding allowed Yunis and Ramsay to determine that a deletion in one patient included the sub-bands q14 . 12, q14 . 13, and q14 . 2, and a portion of q14 . 11 and q14 . 3. We report the results of similar cytogenetic techniques applied in the case of a 26 month old Caucasian female with unilateral retinoblastoma, moderate developmental delay, and subtle dysmorphology. Prometaphase banding of cultured skin fibroblasts revealed the karyotype: mos46,XX/46,XX,del(13)(q13 . 1q14 . 11). Only the sub-band q14 . 11 is deleted in both our patient and that of Yunis and Ramsay. The results are consistent with the localisation of the retinoblastoma susceptibility gene(s) in the sub-band 13q14 . 11. Electrophoretic analysis and activity assays of red blood cell esterase D are consistent with hemizygous expression of that marker in our proband. Comparison with published esterase D analyses in families with retinoblastoma permits the assignment of the esterase D locus to that same sub-band, 13q14 . 11.

Carboxylesterase↗
PubMed2003

Angioedema of the tongue due to acquired C1 esterase inhibitor deficiency.

We describe the management of an 83-year-old woman who presented with upper airway obstruction due to angioedema of the tongue. Following definitive airway management, investigation showed a diagnosis of acquired C1 esterase inhibitor deficiency (acquired angioedema) that was considered to be subsequent to haematological malignancy. Resolution of the macroglossia followed treatment with C1 esterase inhibitor concentrate, but the patient failed to wean from ventilatory support and died in the Intensive Care Unit. This case report highlights the potential for acquired angioedema to cause upper airway obstruction. The various treatment modalities for acquired C1 esterase inhibitor deficiency are summarized.

Aged↗