Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human bone marrow cultured in the presence of human rIL-3 has been reported to give rise to basophils. In contrast, mouse bone marrow, cultured in the presence of mouse IL-3, leads to the growth of mast cells. To determine if human rIL-3 might also stimulate the growth of human mast cells, we cultured human bone marrow in the presence of human rIL-3 in suspension cultures, methylcellulose, and in "interphase" cultures where cells are layered over agar. The presence of mast cells was determined using a variety of histochemical techniques. In agreement with previous reports, basophil-like cells were identified in all culture systems. Mastlike cells were identified only in interphase cultures. By 3 wk, such cultures consisted of basophil-like cells (20 to 50%) and mastlike cells (1 to 5%). Cultures supplemented with rIL-4 showed no additional increase in basophil-like and mastlike cells. Both basophil-like and mastlike cells fluoresced with o-phthaldialdehyde and exhibited IgE receptors. Unlike basophil-like cells, mastlike cells were chloroacetate esterase, amidase, and human mast cell tryptase positive. We conclude that human rIL-3 can support the growth of human mastlike cells under selected culture conditions.
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PMID:IL-3-dependent growth of basophil-like cells and mastlike cells from human bone marrow. 264 50

From bovine brain an esterase was purified 2,600-fold in an overall yield of 5.6%. For the isolation ion-exchange chromatographies, gel filtration, and preparative isoelectric focusing were used. The molecular mass is 56 kDa after gel chromatography on Sephacryl S-200 and 51 kDa after HPLC, the pH-optimum at 7.4, and the isoelectric point in the range of pH 5.8-6.1, as estimated from preparative isoelectric focusing. The substrate specificity of this enzyme was tested with various naturally occurring O-acylated sialic acids, synthetic carbohydrate acetates, and other esters. Besides aromatic acetyl esters such as e.g. alpha-naphthyl acetate, the highest preference was for N-acetyl-9-O-acetylneuraminic acid, followed by N-acetyl-4-O-acetylneuraminic acid. Other primary acetyl esters such as 6-O-acetylated D-glucose and 2-acetamido-2-deoxy-D-mannose were not hydrolyzed. The 9-O-acetyl derivative of the naturally occurring unsaturated sialic acid 2-deoxy-2,3-didehydro-N-acetylneuraminic acid, however, is a substrate for this esterase. Whereas N-acetyl-9-O-acetylneuraminic acid as a component of sialyllactose is nearly as well hydrolyzed as the corresponding free sialic acid, O-acetylated sialoglycoconjugates with high molecular weights (mucins, serum glycoproteins, gangliosides) are not hydrolyzed by this esterase. N-Acetylated sialic acids are better substrates than the analogous N-glycoloyl derivatives. Esterification of the carboxyl function of sialic acids prevents the action of the esterase on the O-acetyl groups. The enzyme has no carboxyl esterase or amidase activity, and does not act on acetylcholine. It hydrolyzes almost exclusively acetyl esters. Inhibition studies suggest that it has a catalytically active serine residue.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Partial purification and characterization of sialate O-acetylesterase from bovine brain. 277 45

A serine protease with a pH optimum from 7 to 9 and activity over the range of pH 3 to 10 was isolated and purified from culture filtrates of Penicillium charlesii 16 days after inoculation. The enzyme was purified by the following sequence of procedures: (i) gel permeation chromatography through Sephacryl S-200, (ii) DEAE-Sepharose anion-exchange chromatography, and (iii) fast protein liquid chromatography (FPLC) over Superose 12. Anion-exchange chromatography separated the protease activity into a major activity (protease PII, 82%) and two minor activities (proteases PI and PIII, 10 and 8%, respectively, of the total activity). Protease PII has a molecular mass of 44 kilodaltons. Purified preparations of this enzyme are susceptible to autodegradation. FPLC of heat-treated PII gave one major species (PIIa), whereas untreated enzyme resulted in three species (PIIb, PIIc, and PIId). PIIb and PIIc also catalyzed the hydrolysis of protein (hide powder azure). PIIb and PIIc were in the molecular mass range of 10 to 20 kilodaltons. Protease PII is completely inhibited by phenylmethylsulfonyl fluoride (PMSF). The protease has primary substrate specificity for phenylalanyl or arginyl amino acyl residues attached to amines. The enzyme has amidase, but no esterase activity toward similar synthetic substrates such as occurs with trypsinlike microbial serine proteases. The addition of PMSF (final concentration, 10(-4) M) to 1- and 2-day-old cultures of P. charlesii inhibited the production of extracellular peptidophosphogalactomannan (pPGM) by 41 and 34%, respectively, and inhibited the alkaline protease activity by 85%. These results suggest that the production and release of pPGM may be affected by alkaline protease.
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PMID:Isolation, purification, and properties of Penicillium charlesii alkaline protease. 279 29

We have identified and isolated two new calcium-activated neutral hydrolases from human ventricular muscles. The one is an esterase, of which molecular weight was 300,000, required millimolar concentration of Ca2+, hydrolyzed Ac-Tyr-OEt X H2O, optiaml pH at 7.0. The other is an amidase, of which molecular weight was 70,000, also required millimolar concentration of Ca2+, hydrolyzed a synthetic substrate for chymotrypsin, Suc-Leu-Leu-Val-Tyr-MCA, with optimal pH at 7.2. Both enzymes did not degrade casein or contractile proteins (myosin, actin, troponin and tropomyosin). Their activities were not inhibited by exogenous protease inhibitors, leupeptin, antipain, monoiodoacetic acid and chymostatin, while the amidase activity was blocked by the endogenous inhibitor against calcium-activated neutral protease (CANP). Thus, their characters are different from chymotrypsin or CANP and they seems to be new hydrolases in the human heart.
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PMID:Identification of two new calcium dependent hydrolases in the human heart. 301 Sep 97

Several commercially available enzymes were tested for their ability to hydrolyze amino acid carbamates. No activity was found with pig liver esterase, the hydantoinase from Pseudomonas fluorescens DSM 84, or the urease from jack beans. A stereoselective cleavage of the carbamyl group yielding L-amino acids was observed by acylase and acetylcholinesterases from bovine and human erythrocytes. Racemic mixtures of N-(methoxycarbonyl)-DL-alanine, N-(ethoxycarbonyl)-DL-alanine, and the corresponding valine carbamates are hydrolyzed to L-alanine and L-valine, respectively, by acylases leaving the D-amino acid carbamates unchanged. The lysine carbamates were not hydrolyzed by acylases. In contrast only the methoxycarbonyl amino acids were split by acetylcholinesterases, which, however, also cleave alpha, epsilon-(N-methoxycarbonyl)-DL-lysine stereoselectively at the alpha position, yielding epsilon-N-methoxycarbonyl-L-lysine. The optimum pH for enzymatic activity of hog kidney acylase was 7.5 and a Km value of 8.2 mM for N-(methoxycarbonyl)-DL-alanine was determined. For the acetylcholinesterases the reaction rate reaches an optimum between pH 7.5 and 8. The Km value was 68 mM for N-(methoxycarbonyl)-DL-alanine.
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PMID:Studies on the enzymatic hydrolysis of amino acid carbamates. 311 96

Sialate 9(4)-O-acetylesterases (EC 3.1.1.53) have been isolated from equine liver, bovine brain and influenza C virus. In this latter case, the esterase represents the receptor-destroying enzyme of the virus. The kinetic properties of these enzymes were determined with Neu5,9Ac2 and in part with 4-methylumbelliferyl acetate and Neu5,9Ac2-lactose. The Km values vary between 0.13 and 24 mM and the Vmax values from 0.55 to 11 U/mg of protein. The pH optima are in the range of 7.4-8.5, the molecular masses at 56,500 and 88,000 Da. In addition to a fast hydrolysis found for aromatic acetates, such as 4-methylumbelliferyl acetate or 4-nitrophenyl acetate, N-acetyl-9-O-acetylneuraminic acid is de-O-acetylated at the highest relative rate. Other substituents at the 9-position, such as lactoyl residues, or acetyl groups at other positions within the side chain are not hydrolyzed. Neu4,5Ac2, however, is a substrate for all 3 enzymes. The hydrolysis rates of this ester function, which renders sialic acids resistant to the action of sialidases, vary from 3 to 100% relative to Neu5,9Ac2. Whereas Neu5,9Ac2-lactose is hydrolyzed by the bovine and viral esterases, other O-acetylated sialic acids in glycoconjugates are only attacked by the enzyme from influenza C virus and not by that from bovine brain. The esterase from horse liver also releases 4-O-acetyl groups from equine submandibular gland mucin. By incubation with appropriate substrates and inhibition studies, carboxylesterase, amidase and choline esterase activities were excluded, as well as the cleavage of other acyls, e.g., butyryl groups. Thus, the enzymes investigated belong to the acetylesterases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sialate O-acetylesterases: key enzymes in sialic acid catabolism. 314 20

gamma-Thrombin was produced during autolysis or limited proteolysis of coagulant gamma-thrombin. This thrombin form loses its ability to coagulate fibrinogen but preserves the esterase and amidase activity on the low-molecular-weight synthetic substrates. This evidences for the integrity of the active site of gamma-thrombin and for the integrity break of the enzyme molecule region responsible for the binding with fibrinogen. gamma-Thrombin with the minimal coagulating activity, possessing high esterase and amidase activity is obtained. Fibrin-agarose possessing affinity to gamma-thrombin and specifically not binding gamma-thrombin was used to remove admixtures of the coagulant gamma-thrombin from the preparations of gamma-thrombin obtained during the enzyme autolysis.
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PMID:[Affinity chromatography of human gamma-thrombin on fibrin-agarose]. 318 51

N-Hydroxy-2-acetamidofluorene (N-OH-AAF), a carcinogenic N-arylhydroxamic acid, is a selective and irreversible inhibitor of arylamine N-acetyltransferase (NAT) activity in vitro. The present study demonstrates that intraperitoneal administration of N-OH-AAF to hamsters caused an irreversible reduction of the hepatic transacetylase activity that catalyzes the transfer of the acetyl group from N-OH-AAF to 4-aminoazobenzene (AAB), but did not affect the acetyl coenzyme A (CoASAc) dependent NAT that is responsible for acetylation of p-aminobenzoic acid (PABA). A 40% loss of N-OH-AAF:AAB transacetylase activity occurred 4 hr after administration of 50 mg/kg of N-OH-AAF. To determine whether biotransformation of N-OH-AAF is a factor in determining its ability to inactivate N-OH-AAF:AAB transacetylase activity in vivo, the enzyme-inducing agent phenobarbital and the esterase/acylamidase inhibitor bis(p-nitrophenyl)phosphate (BNPP) were administered to the animals prior to the administration of N-OH-AAF. The loss of N-OH-AAF:AAB transacetylase activity was prevented by treatment of the animals with either phenobarbital or with BNPP. The ability of the esterase/acylamidase inhibitor, BNPP, to prevent the N-OH-AAF-mediated loss of transacetylase activity indicates that, in contrast to the inactivation process in vitro, esterase-catalyzed deacetylation of N-OH-AAF may be required for transacetylase inactivation in vivo. It is proposed that in vivo the endogenous acetyl donor, CoASAc, acetylates the enzyme and prevents the deacetylation of N-OH-AAF by NAT, thereby impeding the N-OH-AAF-mediated inactivation process, but facilitating enzyme inactivation by N-hydroxy-2-aminofluorene. The latter proposal was supported by the demonstration that CoASAc inhibited the in vitro inactivation of N-OH-AAF:AAB transacetylase activity by N-OH-AAF.
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PMID:Hepatic N-acetyltransferases: selective inactivation in vivo by a carcinogenic N-arylhydroxamic acid. 325 89

A relatively simple procedure for isolation and purification of human blood plasma kallikrein (HPK) by QAE-Sephadex A-50 SP-Sephadex C-50 and affinity chromatography on Sepharose 4B with immobilized soybean trypsin inhibitor with the activity yield of about 40% has been developed. The method allows for simultaneous isolation of low (LMW) and high molecular weight (HMW) kininogens from the same HPK sample. HPK preparations are homogeneous upon 7.5% polyacrylamide gel electrophoresis in the presence of 0.1% SDS; its Mr is 90,000. After treatment with beta-mercaptoethanol, HPK dissociates into two fragments with Mr of 43,000 and 37,000. HPK preparations have high specific activities of esterase (31 microM/min), amidase (78 microM/min), and kininogenase (420 micrograms equiv. bradikinin/min). The high degree of protein purification was demonstrated by titration of active centers with 4-methylumbelliferylguanidine benzoate. The values of equilibrium dissociation constants for the HPK complex with aprotinin (Ki) equal to 1 X 10(-8) M (ethyl ester of N-alpha-benzoyl-L-arginine) and 1,5 X 10(-9) M (HMW) were determined. The kinetics of HPK-induced liberation of bradikinin from purified preparations of HMW and LMW was studied. The kinetic parameters (Km, kcat and kcat/Km) of this reaction suggest a high affinity of HPK for HMW, but not for LMW. LMW does not compete with HMW for the enzyme active center. It is assumed that LMW is not a physiological substrate for HPK.
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PMID:[Various properties and kinetics of interaction of high and low molecular weight human kininogens with human plasma kallikrein]. 363 30

In order to investigate the validity of urinary kallikrein (KAL) measurement, comparative studies were performed among the values obtained by various methods of urinary KAL measurements. Daily urine samples were collected from 37 hospitalized normal subjects (NS, 21 essential hypertensives without complications (EHT) and 20 patients with renal diseases associated with proteinuria (PU). Urinary KAL excretions were determined by direct radioimmunoassay (RIA), kininogenase assay (K-genase), TAMe esterase assay (TAMe), and PPA-MCA (MCA) and PPA-NE amidase assay (NE). By the desalting procedure, urinary KAL levels showed significant changes in TAMe, MCA and NE, but not in d-RIA and K-genase in all three groups. In TAMe, MCA and NE, the recovery of added KAL in urine was significantly lower in non-desalted samples in both EHT and PU, but not in NS. Impaired recovery and correlations between d-RIA or K-genase and TAMe, MCA or NE in non-desalted samples were improved by desalting. Although good correlations were observed between d-RIA or K-genase and TAMe, MCA or NE in desalted samples, the slopes of curves were steeper in EHT and PU than in NS, suggesting that the synthetic substrate methods still have some problems in the KAL measurement in these pathological states, KAL inhibitor, aprotinin and gabezate mesilate did not suppress the esterclytic and amidolytic activities completely, but suppressed K-genase activity completely in PU urine samples, suggesting that certain kinds of non-KAL esterases might remain in PU urine samples. Thus, d-RIA and K-genase appear to be the most reliable methods in the measurement of urinary KAL quantity and activity, respectively.
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PMID:A comparative study of the measurement of urinary kallikrein by various methods in patients with essential hypertension and patients with proteinuria. 364 32


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