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

---

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

Dimethyl sulfoxide produces an opposite effect on the esterase and amidase activities of bovine thrombin. The esterase activity is increased by two fold but the amidase activity is decreased to 9% of the initial activity in 20% dimethyl sulfoxide. The stimulation of the esterase activity is due to the change in Vmax rather than Km for the substrate p-Tosyl-L-Arginine methyl ester. The inhibition of the esterase activity of thrombin by NaCl is not affected due to the addition of dimethyl sulfoxide. Ki for NaCl, 0.03 M, is the same for both in the absence and in the presence of 10% dimethyl sulfoxide. The catalytic activity of thrombin is inhibited by heparin. This effect is significantly decreased by dimethyl sulfoxide. The dissociation constant of heparin-thrombin complex, measured in the absence and in the presence of 10% dimethyl sulfoxide are 4 nM and 28 nM respectively. Thermal stability of thrombin, determined by monitoring catalytic activity, is increased in the presence of dimethyl sulfoxide. The enhancement of the fluorescence intensity of thrombin in the presence of dimethyl sulfoxide reflects the contribution of more exposed tryptophanyl residues. The alteration of the conformation of the enzyme structure due to the perturbation of the aqueous medium by dimethyl sulfoxide, has been attributed to these observed effects.
...
PMID:The catalytic activity and physical properties of bovine thrombin in the presence of dimethyl sulfoxide. 684 75

The three enzyme activities, carboxylesterase, aryl acylamidase and cholinesterase activities, have been found in rat and human sera. Rat serum carboxylesterase associated with serum aryl acylamidase activity, but not with serum cholinesterase activity, was purified by ammonium sulfate precipitation, followed by successive chromatographies on DEAE-cellulose, blue Sepharose and QAE-Sephadex, and then electrophoresis. Evidence for the identity of the two enzymes, carboxylesterase and aryl acylamidase, was their co-elution profiles and co-purification in the different steps, including electrophoresis, with constant ratios of specific activities and percentage recoveries. Human serum carboxylesterase associated with serum cholinesterase, purified earlier, was compared with the rat serum esterase. Human serum carboxylesterase and aryl acylamidase activities were inhibited by serotonin and neostigmine, whereas rat serum carboxylesterase and aryl acylamidase activities were not affected by these compounds. Tyramine activated human but not rat aryl acylamidase. Rat and human serum esterase activities were both strongly inhibited by the diisopropylfluorophosphate. Both esterases catalyzed the hydrolysis of short-chain triacylglycerols, such as tributyrin, and medium-chain monoacylglycerols, such as monocaprin, but not the hydrolysis of long-chain triacylglycerols.
...
PMID:Carboxylesterases in rat and human sera and their relationship of serum aryl acylamidases and cholinesterases. 685 27

We studied the effect of ions on the ability of purified human urinary kallikrein to cleave its natural substrate (kininogen) as well as two synthetic substrates, tosylarginine [3H]methyl ester and Pro-Phe-Arg-[3H]benzylamide. The kininogenase activity of kallikrein is markedly dependent upon the concentration of cations in vitro. Kininogenase activity is very low when measured in a low electrolyte buffer. The addition of cations to the reaction mixture increases activity by up to 27-fold. Maximum activity is achieved with 100 mM sodium, 100 mM potassium, or 20 mM magnesium. The activity is stable at higher concentrations of cation. Renal kallikrein is believed to act within distal tubular fluid in vivo. The concentration of cations in this fluid varies widely in response to alterations in salt and water metabolism. Thus, the relationship of kininogenase activity to the concentration of cations demonstrated in vitro may be relevant to the activity of kallikrein at its presumed site of action in the kidney. In separate experiments, we evaluated the effect of ions on the amidase and esterase activities of kallikrein which are the basis of several assays in routine use for physiological studies. In contrast to their stimulatory effect on kininogenase activity, cations inhibit amidase and to a lesser extent esterase activity. Additional studies indicate that urinary cations probably account entirely for the well known ability of normal urine to inhibit the amidase and esterase activities of kallikrein.
...
PMID:The effect of cations on the activity of human urinary kallikrein. 692 Dec 2

After partial reduction of disulfide bonds in the thaumatins, the sweet-tasting proteins from the fruits of Thaumatococcus danielii Benth, a rapid autodigestion was demonstrated. In the presence of suitable substrates, the reduced thaumatins showed protease, amidase and esterase activity. Thiol-blocking reagents like mercury(II) chloride inhibited the enzymatic activity. Of the thaumatins b, c, I, II and III (with increasing isoelectric points), thaumatin I showed the lowest enzymatic activity. In this series, the enzymatic activity increased from thaumatin I to thaumatin III as well as from thaumatin I to thaumatin b. Acetylation of the epsilon-amino group of lysine residues in the thaumatins by acetic anhydride, causing a decrease in basicity, led to an increase in enzymatic activity, which is correlated with the number of acetyl groups introduced. Comparison of the amino acid sequence of thaumatin I with that of cysteine proteases of plant origin showed no similarities. Moreover, the thaumatins lack histidine, one of the amino acids in the active site of the cysteine proteases. Monellin, the sweet-tasting protein from the fruits of Dioscoreophyllum cumminsii Diels, is not enzymatically active. However, when monellin with acetylated epsilon-amino groups of lysine residues was brought into a reducing environment it appeared to be enzymatically active. The similarities in properties of the thaumatins and monellin suggest a structural relationship between these proteins.
...
PMID:Enzymatic properties of the sweet-tasting proteins thaumatin and monellin after partial reduction. 698 15

Pronase-resistant low molecular weight stimulators for the activation of proacrosin to acrosin were found in rhesus monkey oviduct fluid collected before, during and after ovulation, but the presence of high concentrations of acrosin inhibitors before and after ovulation partly masked the stimulation in unfractionated fluid. This low molecular weight fraction of oviduct fluid had no detectable esterase or amidase activity by itself, and the stimulating factors were sensitive to digestion by hyaluronidase and chondroitin ABC lyase and were presumed to be glycosaminoglycans. Heparin and hyaluronic acid had similar effects. The presence of soluble glycosaminoglycans at the site of fertilization suggests that they may have a role in capacitation and fertilization.
...
PMID:Stimulation of rhesus monkey (Macaca mulatta) proacrosin activation by oviduct fluid. 700 Oct 8

Two amidases have been partially purified from the slime mold Dictyostelium discoideum; these act sequentially on the beta-hydroxymyristyl-amide groups present in the lipopolysaccharide derivative (4'-O-phosphoryl-N-beta-hydroxymyristyl-D-glucosaminyl)-beta-(1 leads to 6)-N-beta-hydroxymyristyl-D-glucosamine-1-phosphate (III). Amidase-I, which specifically removes the myristyl chain near the 1-phosphate of compound III (apparent Km, 3.7 microM), has been purified 110-fold from a lysate of D. discoideum NC4 cultivated on Escherichia coli. The partially purified enzyme contains no other amidase or phosphatase activities; however, an esterase activity can be detected. The second amidase has been purified about 12-fold from the extracellular fluid of D. discoideum AX3 cultured axenically. This amidase hydrolyzes the distal amide linkage in III (apparent Km, approximately 20 microM) only after prior deacylation of the first site by amidase-I. The preparation is free from phosphatases and glycosidases that can act on lipopolysaccharide. The differential expression of the amidases in D. discoideum and some of their kinetic properties have been described. The amidases should prove useful in structure-function studies of lipopolysaccharide.
...
PMID:Fatty acyl amidases from Dictyostelium discoideum that act on lipopolysaccharide and derivatives. I. Partial purification and properties. 710 2

A semiquantitative assessment of estrase and deaminase distributions in hairless mouse skin was performed in vitro. The enzyme activities were quantified using 3H-vidarabine and tis 5'-valerate as the substrates. Full-thickness skin of the hairless mouse was cut into two halves, and each half was homogenized in pH 7.4 buffer. BQOTH THE SUPERNATE AND THE RESIDUE OF THE HOMOGENATE were assayed for esterase and deaminase activities. Results show that the outer half-thickness of the skin contained more esterase but slightly less deaminase than the other half. The characteristics of the esterase and the deaminase reactions also were studied employing the crude enzyme extract; these reactions were essentially irreversible. The deaminase reaction was in the linear region of Michaelis-Menten kinetics for substrate concentrations up to 4.5 x 10(-5) M.
...
PMID:Physical model evaluation of topical prodrug delivery--simultaneous transport and bioconversion of vidarabine-5'-valerate IV: Distribution of esterase and deaminase enzymes in hairless mouse skin. 739 37

The mathematical problem of simultaneous transport and metabolism in the case of nonuniform enzyme distributions in the skin was solved, and the solutions were used for analyzing experimental data. Experimental data were obtained from permeation experiments with 3H-vidarabine and its 5'-valerate using cellophane tape-stripped hairless mouse skin. Results of the analyses revealed that the esterase activity was four to nine times higher in the epidermis than in the dermis, whereas the deaminase activity was about the same in the two strata. These results were in good agreement with independent experiments using tissue homogenates. The enzyme distributions and the previously reported diffusivities were employed in generating concentration profiles for the prodrug and the drug in the skin. These results may be used in predicting the possible therapeutic effect of the prodrug when it is topically applied.
...
PMID:Physical model evaluation of topical prodrug delivery--simultaneous transport and bioconversion of vidarabine-5'-valerate V: Mechanistic analysis of influence of nonhomogeneous enzyme distributions in hairless mouse skin. 739 38

Elastases are unique among the proteases in that they are capable of hydrolyzing the scleroprotein elastin. The enzymes include pancreatic elastases 1 (Protease E) and 2, and neutrophil elastase. These three elastases also have esterase and amidase activity toward synthetic substrates such as succinyl-trialanine-p-nitroanilide. Although the three enzymes are similar to each other in enzyme activity, they are quite different in immunoactivity. Therefore, each elastase has its own specific immunoassay either by RIA or EIA. Serum immunoreactive pancreatic elastases reflect disease conditions of pancreatic diseases, especially acute pancreatitis and pancreatic cancer. On the other hand, serum neutrophil elastase increases in various inflammatory diseases or conditions.
...
PMID:[Elastase]. 760 77

Trypsinogen is a serine protease zymogen (EC.3.4.21.4) which has proved to be of key significance in a family of about 20 structurally and functionally related pancreatic digestive enzymes. This study was an endeavour to isolate, purify and characterize a stable form of ostrich trypsinogen, which has thus far not yet been accomplished. Trypsinogen (anionic) was isolated and purified by alkaline extraction of pancreatic acetone powder, followed by Toyopearl DEAE 650M, hydroxylapatite and LBTI-Sepharose affinity chromatography. The enzyme was chemically physically and kinetically characterized, using amidase and esterase activity and spectrofluorometric determinations. Effects of CaCl2 and pH, among others, were examined. Purification of homogeneous anionic ostrich trypsinogen was achieved. Immunochemical analysis and spectrofluorometric reaction with sulphonyl-Ala-Ala-Pro-Arg-7-amino-4-methylcoumarin indicated trypsin-free ostrich trypsinogen, with an average Mr of 23,016 and a pI of 4.93. N-terminal sequence data revealed an unique activation peptide sequence, VPGDADDDK. Certain concentrations of Ca2+ enhanced trypsinogen activation, whilst others appeared to have the opposite effect. The kcat/Km values obtained at different pHs, using N alpha-benzoyl-DL-arginine-p-nitroanilide, p-toluenesulphonyl-arginine-methylester and p-toluenesulphonyl-lysine-methylester, followed the pH profile activity trend closely, with maximum catalytic activity at about pH 8 for both ostrich and bovine activated trypsinogen. Ostrich trypsin has significantly higher amidase activity than bovine trypsin, while esterase activities of the two enzymes have an inverse ratio. Kinetic pKa values were 7.2 and 7.4 for ostrich and bovine activated trypsinogens, respectively. The existence of ostrich trypsinogen in a now homogeneous stable form, free of autocatalytic inducing impurities, together with its characterization scenario will hopefully make a significant contribution to the field of comparative biochemistry. This study also confirms that ostrich trypsinogen is closely related to its serine protease counterparts.
...
PMID:Ostrich trypsinogen: purification, kinetic properties and characterization of the pancreatic enzyme. 764 28


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---