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PubMed1993

Effect of ethanol and progesterone on monoamine oxidase activity in cultured cells of human term placenta.

OBJECTIVE: The aim of this study was to evaluate the effect of ethanol and progesterone on the monoamine oxidase activity in cultured human term placental cells. STUDY DESIGN: Human placental cells were prepared from normal human term placentas by enzymatic dispersion in Dulbecco's modified Eagle medium. The viability of placental cells prepared by our method was 90%, and the yield of placental cells was 0.6 x 10(6) cells per gram of wet placental tissue. Five milliliters of Dulbecco's modified Eagle medium containing 3 x 10(5) placental cells was plated in a 25 cm2 flask and cultured for 8 days in an incubator at 37 degrees C under an atmosphere of 5% carbon dioxide and 95% oxygen with a saturated humidity. During the culture period the culture medium was replenished every 2 days. A confluent monolayer condition was achieved after 8 days in culture. The cultured placental cells were treated with different concentrations of ethanol (0, 34.6, and 69.2 mmol/L) and progesterone (0, 16, and 32 mumol/L) on day 8 of culture for 48 hours. At the end of treatment placental cells from control and treated flasks were harvested for the analysis of monoamine oxidase activity by spectrophotometry. The effects of ethanol and progesterone on cultured placental cells were statistically analyzed by one-way analysis of variance followed by Duncan's multiple comparisons procedure. RESULTS: A human placental cell culture system has been established from normal human term placentas. The monoamine oxidase activity in 8-day-cultured human term placental cells was significantly higher than that of freshly prepared placental cells. Ethanol concentrations at 34.6 and 69.2 mmol/L significantly increased and progesterone concentration at 32 mumol/L significantly decreased the monoamine oxidase activity. CONCLUSION: These results suggest that the cultured human term placental cells can be used to examine the in vitro effects of ethanol and progesterone on monoamine oxidase activity. However, the physiologic significance of progesterone's inhibitory effect and the stimulatory effect of ethanol monoamine oxidase activity in the in vivo system have yet to be further investigated.

Cells, Cultured↗
PubMed1984

Diamine oxidase activity in human decidua and endometrium.

The activity of diamine oxidase, the enzyme that catalyzes the oxidative deamination of putrescine, spermidine, histamine, and other substances involved in the regulation of cell proliferation and immune responses, increases up to 1000-fold in blood of pregnant women. In vivo experiments have shown that progestins stimulate diamine oxidase in the rodent uterus. We examined diamine oxidase activity in human endometrium at different phases of the menstrual cycle and in decidua from first-trimester pregnancies. Enzyme activity was also assayed in tissues and media of cultured human endometrium and decidua in the presence of estradiol or medroxyprogesterone acetate. Enzyme activity in first-trimester decidual tissues (286 +/- 86 mU of diamine oxidase per milligram of DNA; mean +/- SEM) was considerably higher (p less than 0.001) than that in endometrium (2.6 +/- 1.6), and the activity increased from 6 to 17 weeks of pregnancy. No significant differences were detected in proliferative and secretory endometrium. Activities in media of endometrium in organ culture generally were below detectability. Decidua secreted large amounts of the enzyme into the medium (160 to 600 mU per milligram of DNA per day), greatly exceeding the initial tissue activities. Bovine serum, when added to culture media, caused a marked increase in diamine oxidase levels, whereas estradiol (10(-8) mol/L) or medroxyprogesterone acetate (10(-6) mol/L) did not. Kinetic analysis showed a Michaelis constant of 7.4 X 10(-6) mol/L with putrescine as the substrate. Spermidine and histamine were competitive inhibitors of putrescine with an inhibition constant of 1.1 X 10(-4) and 3.5 X 10(-6) mol/L, respectively. These results demonstrate synthesis and export of diamine oxidase by decidua in organ culture, stimulation of activity by serum factors, and competition of histamine, spermidine, and putrescine for the enzyme.

Amine Oxidase (Copper-Containing)↗
PubMed1992

Purification of human placenta diamine oxidase.

Diamine oxidase (histaminase) is produced at very high levels by the decidual cells of the placenta. The presence of diamine oxidase has been demonstrated in human neutrophils. Purification of human placenta diamine oxidase was performed by four subfractionation steps and led to the isolation of one polypeptide whose molecular weight was 84,000, as assessed by SDS PAGE. Using polyclonal antibodies raised against the purified enzyme, we have demonstrated that the neutrophil diamine oxidase is immunochemically identical to the placental diamine oxidase. Development of immunological methods will be useful for detection and quantitation of diamine oxidase in neutrophils during the inflammation process.

Amine Oxidase (Copper-Containing)↗
PubMed2001

Structure-function relationship in the interaction of mastoparan analogs with neutrophil NADPH oxidase.

Mastoparan, an amphiphilic cationic tetradecapeptide was previously shown to block activation of the NADPH oxidase in the cell-free system presumably by association with a cytosolic component/s of the enzyme. Blockade of oxidase activation was now demonstrated in the semirecombinant NADPH oxidase system. The structural basis of the inhibitory effect of MP on oxidase assembly was explored employing a variety of truncated and specifically substituted synthetic peptide analogs. The data indicated that an alpha helical fold, positive net charge, hydrophobicity and amphiphilicity were essential for the inhibitory potency and that peptide analogs below eleven residues were inactive. To identify the MP-binding oxidase subunit three different binding assays were carried out utilizing free or immobilized recombinant p47-phox, p67-phox, p40-phox and Rac1 in conjunction with immobilized MP or soluble (125)I-tyr-MP, respectively. The data implicated p67-phox as the main MP-binding component. The binding site on the p67-phox was localized to the 1-238 aminoterminal fragment of the molecule. NADPH oxidase activation supported by this fragment was inhibitable by MP. In addition, SH3 domains of p47-phox and p40-phox and the carboxyterminal SH3 domain of p67-phox exhibited a low affinity towards MP.

Cell-Free System↗
PubMed2001

Differential NADPH- versus NADH-dependent superoxide production by phagocyte-type endothelial cell NADPH oxidase.

OBJECTIVE: A poorly characterized phagocyte-type NADPH oxidase, which is reportedly NADH- rather than NADPH-dependent, is a major source of endothelial reactive oxygen species (ROS) production. We investigated the molecular nature of this oxidase and the characteristics of NADPH- versus NADH-dependent O(2)(-) production in endothelial cells of three different species. METHODS: NADPH oxidase expression in human, bovine and porcine endothelial cells was studied by RT-PCR and immunoblotting. O(2)(-) production was assessed by lucigenin chemiluminescence and cytochrome c reduction assay. RESULTS: The NADPH oxidase subunits p47-phox, p67-phox, p22-phox, gp91-phox, and rac1 were all expressed in endothelial cells. NADPH-dependent O(2)(-) production by endothelial cells was readily detectable using lucigenin 5 micromol/l, was minimally affected by increasing lucigenin dose up to 400 micromol/l, and was abolished by diphenyleneiodonium. In contrast, NADH-dependent O(2)(-) production was only detectable with lucigenin > or =50 micromol/l, increased substantially with higher lucigenin dose, and was unaffected by diphenyleneiodonium. Predominance of NADPH- over NADH-dependent O(2)(-) production was confirmed in cell homogenates and by cytochrome c reduction assay. CONCLUSION: Endothelial cells express all components of a phagocyte-type NADPH oxidase. Like the neutrophil enzyme, the endothelial oxidase is preferentially NADPH- rather than NADH-dependent. NADH-dependent O(2)(-) production appears to be an artefact related to the use of lucigenin doses > or =50 micromol/l.

Acridines↗
PubMed1998

Quantitation of three-month intraindividual variability and influence of sex and menstrual cycle phase on CYP1A2, N-acetyltransferase-2, and xanthine oxidase activity determined with caffeine phenotyping.

OBJECTIVE: To evaluate intraindividual variability and the effects of sex and menstrual cycle phase on the activity of cytochrome P450 1A2 (CYP1A2), N-acetyltransferase 2 (NAT2), and xanthine oxidase. METHODS: Ten white men were given 2 mg/kg caffeine orally every 14 days for 3 months. The same dosage of caffeine was given to 10 premenopausal white women during the midfollicular and midluteal phases of three complete menstrual cycles. Phenotype was determined with urinary caffeine metabolite ratios. RESULTS: For CYP1A2, mean metabolic ratio (+/- SD) was 5.97 +/- 2.78 during the midfollicular phase and 5.32 +/- 1.99 during the midluteal phase (p = 0.2). For extensive and poor metabolizer of NAT2. Mean midfollicular phase metabolite ratios were 0.71 +/- 0.060 and 0.37 +/- 0.030, and mean midluteal phase metabolite ratios were 0.69 +/- 0.076 and 0.39 +/- 0.053 (p = 0.9). For xanthine oxidase, mean midfollicular phase metabolite ratio was 0.63 +/- 0.06 and mean midluteal phase metabolite ratio was 0.63 +/- 0.05 (p = 0.3). Among the men, mean CYP1A2, NAT2 rapid and slow acetylator, and xanthine oxidase indices were 9.42 +/- 10.18, 0.66 +/- 0.021, 0.31 +/- 0.056, and 0.64 +/- 0.03. There were no differences in metabolite ratios between men and women for CYP1A2, NAT2 extensive metabolizers, or xanthine oxidase. A statistically significant sex difference was found for poor metabolizers of NAT2 (p < 0.05). Median coefficients of variation for CYP1A2, NAT2 extensive and poor metabolizers, and xanthine oxidase ratios were 16.8% (range, 4.5% to 49.3%), 2.9% (range, 2.2% to 4.7%), 13.4% (range, 7.5% to 27.2%), and 4.5% (range, 2.3% to 13.0%). CONCLUSION: Stratification by menstrual cycle phase or sex need not be performed for pharmacokinetic or clinical investigations of substrates for CYP1A2, NAT2, or xanthine oxidase in which the subject are adults.

Adult↗
PubMed2002

Expression of diamine oxidase (histaminase) in guinea-pig tissues.

The expression of mRNA for diamine oxidase (histaminase) and the enzyme activity in guinea-pig tissues were investigated. Reverse transcription-polymerase chain reaction analysis revealed that the message corresponding to the long form present in humans and rats was expressed abundantly in the small intestine and liver. Small but detectable amounts of diamine oxidase mRNA were observed in the kidney, stomach, cerebellum, thalamus+hypothalamus, and cerebral cortex. Northern blot analysis showed that the message (2.8 kb in size) was observed abundantly in the liver and small intestine and was detectable in the kidney and stomach but not in the brain or lung. In situ hybridization showed that diamine oxidase mRNA was localized throughout the liver and epithelial cells of the small intestine. Diamine oxidase activity was detected at various levels in different tissues of the guinea-pig at the following relative abundance: liver>small intestine>lung, kidney>stomach. Histamine dose-dependently induced the contraction of sections of the guinea-pig small intestine, and the pretreatment of the tissue section with aminoguanidine (100 microM), a diamine oxidase inhibitor, but not with S-[4-(N,N-dimethylamino)butyl]isothiourea (100 microM), an inhibitor of histamine N-methyltransferase, shifted the dose-response curve of histamine-induced contraction to lower concentrations. These results suggest that diamine oxidase has a crucial role in the degradation of histamine in the guinea-pig small intestine and probably in the liver.

Amine Oxidase (Copper-Containing)↗
PubMed1996

Identification of the quinone cofactor in a lysyl oxidase from Pichia pastoris.

A copper amine oxidase from Pichia pastoris is the only known non-mammalian lysyl oxidase [Tur, S.S. and Lerch, K. (1988) FEBS Lett. 238, 74-76]. Recently, the cofactor in mammalian lysyl oxidase has been identified as a novel lysine tyrosylquinone moiety [Wang, S.X., Mure, M., Medzihradszky, K.F., Burlingame, A.L., Brown, D.E., Dooley, D.M., Smith, A.J., Kagan, H.M. and Klinman, J.P. (1996) Science 273, 1078-1084]. In order to identify the cofactor in P. pastoris lysyl oxidase, we have isolated the phenylhydrazone-derivative of the active-site peptide. This peptide has the active-site sequence conserved among topa quinone containing amine oxidases. The resonance Raman spectra of the phenylhydrazone derivatives of the enzyme, active-site peptide, and a topa quinone model compound are essentially identical. Collectively, these results establish that P. pastoris lysyl oxidase is a topa quinone enzyme.

Amino Acid Sequence↗
PubMed1997

Micro-injection of recombinant lysyl oxidase blocks oncogenic p21-Ha-Ras and progesterone effects on Xenopus laevis oocyte maturation.

Previous evidence suggested an anti-oncogenic role for lysyl oxidase, mainly in ras-transformed cells. Here we prove that recombinant lysyl oxidase is actually able to antagonize p21-Ha-Ras-induced Xenopus laevis oocyte maturation. Lysyl oxidase was also effective on progesterone-dependent maturation, indicating a block lying downstream of Ras. Maturation induced by activated 'maturation promoting factor', normally triggered by progesterone, was also inhibited by lysyl oxidase. Finally, lysyl oxidase did not abolish p42Erk2 phosphorylation upon maturation triggering, suggesting a block downstream of Erk2. Further investigation showed that lysyl oxidase action depends on protein synthesis and is therefore probably mediated by a newly synthesized protein.

Aminopropionitrile↗
PubMed1999

A single amino acid change in the plant alternative oxidase alters the specificity of organic acid activation.

The alternative oxidase is a quinol oxidase of the respiratory chain of plants and some fungi and protists. Its activity is regulated by redox-sensitive disulphide bond formation between neighbouring subunits and direct interaction with certain alpha-ketoacids. To investigate these regulatory mechanisms, we undertook site-directed mutagenesis of soybean and Arabidopsis alternative oxidase cDNAs, and expressed them in tobacco plants and Escherichia coli, respectively. The homologous C99 and C127 residues of GmAOX3 and AtAOX1a, respectively, were changed to serine. In the plant system, this substitution prevented oxidative inactivation of alternative oxidase and rendered the protein insensitive to pyruvate activation, in agreement with the recent results from other laboratories [Rhoads et al. (1998) J. Biol. Chem. 273, 30750-30756; Vanlerberghe et al. (1998) Plant Cell 10, 1551-1560]. However, the mutated protein is instead activated specifically by succinate. Measurements of AtAOX1a activity in bacterial membranes lacking succinate dehydrogenase confirmed that the stimulation of the mutant protein's activity by succinate did not involve its metabolism. Examples of alternative oxidase proteins with the C to S substitution occur in nature and these oxidases are expected to be activated under most conditions in vivo, with implications for the efficiency of respiration in the tissues which express them.

Amino Acid Substitution↗
PubMed2001

Xanthine oxidase in eutopic and ectopic endometrium in endometriosis and adenomyosis.

OBJECTIVE: To investigate the expression of xanthine oxidase in eutopic and ectopic endometrium in endometriosis and adenomyosis. DESIGN: Immunohistochemical identification of xanthine oxidase in endometrial tissues by using polyclonal antibody. SETTING: University hospital. PATIENT(S): Thirty-four women with endometriosis, 34 women with adenomyosis, and 44 fertile control women. INTERVENTION(S): Biopsy samples were obtained from the endometrium throughout the menstrual cycle. MAIN OUTCOME MEASURE(S): Semiquantitative immunostaining (evaluation nomogram) score of endometrial cells. RESULT(S): The level of xanthine oxidase expression in the glandular epithelium of control varied according to menstrual phase, but no such variation in expression was seen in endometriosis. Variation in xanthine oxidase expression was observed during the menstrual cycle in patients with adenomyosis; this variation differed completely from that in controls. Xanthine oxidase expression was found in ectopic endometrial tissue in all cases. The mean evaluation nomogram levels in the glandular epithelium in adenomyosis tissue were as high as those in the early secretory phase in the eutopic endometrium. CONCLUSION(S): Aberrant expression of xanthine oxidase in eutopic and ectopic endometrium appears to play a pathologic role in endometriosis and adenomyosis.

Anemia, Iron-Deficiency↗
PubMed1988

Reperfusion-induced arrhythmias: a study of the role of xanthine oxidase-derived free radicals in the rat heart.

We have assessed whether oxygen-derived free radicals produced by xanthine oxidase may be an important trigger mechanism in the genesis of reperfusion-induced arrhythmias. We have examined (i) the effects of inhibition of xanthine oxidase by both folic acid solution and amflutizole; (ii) the effects of the inhibitor of xanthine dehydrogenase to xanthine oxidase conversion, soybean trypsin inhibitor; (iii) the effects of administration of superoxide dismutase and catalase, both singly and in combination and (iv) in an isolated rat heart preparation we have investigated the ability of free radical scavengers to reduce reperfusion arrhythmias caused by the infusion of xanthine oxidase and hypoxanthine. The prior administration of folic acid solution, amflutizole, superoxide dismutase, catalase, and superoxide dismutase plus catalase all reduced the incidence of reperfusion-induced arrhythmias and resultant mortality, caused by reperfusion after a transient period of coronary artery occlusion in the anaesthetised rat. Prior administration of soybean trypsin inhibitor significantly reduced mortality. In an isolated, perfused rat heart preparation with temporary coronary artery occlusion, addition of xanthine oxidase-hypoxanthine to the perfusion medium increased the incidence of reperfusion arrhythmias and decreased the total duration of sinus rhythm during reperfusion. Further addition of superoxide dismutase or L-methionine increased significantly the total duration of sinus rhythm. These results suggest that in the rat heart xanthine oxidase may be involved in the genesis of reperfusion-induced arrhythmias.

Allopurinol↗
PubMed2001

Cloning, sequence analysis, and characterization of the 'lysyl oxidase' from Pichia pastoris.

Lysyl oxidase from Pichia pastoris has been successfully overexpressed. EPR and resonance Raman experiments have shown that copper and TPQ are present, respectively. Lysyl oxidase from P. pastoris has a similar substrate specificity to the mammalian enzyme (both have been shown to oxidize peptidyl lysine residues) and is 30% identical to the human kidney diamine oxidase (the highest of any non-mammalian source). This enzyme also has a relatively broad substrate specificity compared to other amine oxidases. Molecular modeling data suggest that the substrate channel in lysyl oxidase from P. pastoris permits greater active site access than observed in structurally-characterized amine oxidases. This larger channel may account for the diversity of substrates that are turned over by this enzyme.

Amino Acid Sequence↗
PubMed1997

Purification and characterization of diamine oxidase from porcine kidney and intestine.

Diamine oxidase, the enzyme catalyzing the oxidative deamination of histamine and other diamines, was purified from porcine kidney and porcine intestine. During all purification steps the enzymes from both tissues showed identical binding and elution characteristics. The native enzymes are homodimeric glycoproteins with an apparent molecular weight of 186 kDa. Under reducing conditions the subunits migrate at 104 kDa on SDS polyacrylamide gels and the deglycosylated subunits migrate at 93 kDa which corresponds to a carbohydrate content of 11%. The native and deglycosylated forms of kidney and intestinal diamine oxidase migrate to the same positions, respectively, on two-dimensional isoelectric focussing/SDS polyacrylamide gels. The sequences of the 21 N-terminal amino acids of both proteins are identical. A polyclonal antibody raised against the kidney enzyme binds equally well to diamine oxidase from both kidney and intestine, inhibits the enzymatic activity, and precipitates all diamine oxidase activity from tissue homogenates. The kidney and intestinal enzymes have identical substrate specificities, efficiently converting aliphatic diamines, histamine, and spermidine. For both enzymes the Km values for histamine, putrescine, and spermidine are 0.02 mM, 0.35 mM, and 3.3 mM, respectively. Spermine, aliphatic monoamines, and aromatic mono- and diamines are poor substrates. In conclusion, the diamine oxidase proteins from porcine kidney and intestine are very likely identical and constitute the only diamine oxidase activity present in these tissues. The structural identity implies identical functions of the proteins in these organs, namely the protection of the organism against high concentrations of diamines.

Amine Oxidase (Copper-Containing)↗
PubMed1986

Monoclonal antibodies to human lysyl oxidase.

Hybridoma antibodies against human lysyl oxidase were produced by fusing Sp. 2.0-Ag 14 myeloma cells with spleen cells from mice hyperimmunized with lysyl oxidase isolated from umbilical cords. Hybridomas positive by enzyme-linked immunosorbent assay (ELISA) for human lysyl oxidase were cloned by the dilution method. Eight hybridomas producing antibodies were isolated, three of which also recognized purified bovine aortic lysyl oxidase in an ELISA. One of these antibodies, monoclonal antibody I, was purified and attached to Sepharose CL-4B. The immobilized antibody was effective in binding an enzymatically active 30,000 dalton species. Immunoblot analysis of four of these antibodies showed reactivity against the 30,000 dalton catalytically active enzyme and the 24,000 dalton fragment of lysyl oxidase. These monoclonal antibodies should be useful tools for studying the localization and biosynthesis of lysyl oxidase.

Amino Acid Oxidoreductases↗
PubMed2000

C-terminal region of the cytosolic subunit p47(phox) is a primary target of conformational change during the activation of leukocyte NADPH oxidase.

The leukocyte NADPH oxidase of neutrophils is a membrane-bound enzyme that catalyzes the production of O(2(-)) from oxygen using NADPH as the electron donor. During activation, the cytosolic oxidase components p47(phox) and p67(phox), each containing two Src homology 3 (SH3) domains, migrate to the plasma membrane, where they associate with cytochrome b(558), a membrane-integrated flavohemoprotein, to assemble the active oxidase. Oxidase activation can be mimicked in a cell-free system using an anionic amphiphile, such as sodium dodecyl sulfate or arachidonic acid and the phosphorylation of p47(phox )with protein kinase C. Activators of the oxidase in vitro cause exposure of p47(phox)-SH3, which has probably been masked by the C-terminal region of this protein in a resting state. We show here that the total protein steady-state intrinsic fluorescence exhibited by the tryptophan residues of p47(phox) substantially decreased when N-terminal truncated p47(phox)-SH3-C was treated with anionic amphiphiles or phosphorylated with protein kinase C. This finding was similar to the results obtained with full-length p47(phox). However, the fluorescence of C-terminal truncated p47(phox)-N-SH3 and both C-terminal and N-terminal truncated p47(phox)-SH3 were not altered by the activators. These results indicate that the C-terminal region of p47(phox) is a primary target of the conformational change during the activation of NADPH oxidase.

Animals↗
PubMed1997

D-amino-acid oxidase is not present in the mouse liver.

Since there are conflict reports on the presence of D-amino-acid oxidase in the mouse liver, this problem was examined. D-Amino-acid oxidase activity was not detected in the homogenates of the mouse liver, lung, or heart, whereas it was detected in the homogenates of the mouse kidney and brain. Western blotting showed that a protein which reacted with the antiserum against pig D-amino-acid oxidase was present in the homogenates of the mouse kidney and brain but not in those of the liver or heart. Northern hybridization using a D-amino-acid oxidase cDNA probe detected a hybridizing signal in poly(A)+ RNAs extracted from the mouse kidney and brain but not in those from the liver, heart, or lung. Reverse transcription-polymerase chain reaction using three primer pairs always amplified D-amino-acid oxidase cDNA fragments of expected sizes in the mouse kidney and brain but very rarely did so in the liver, heart, or lung. The results indicate that D-amino-acid oxidase is not present in the mouse liver in a measurable amount.

Animals↗
PubMed2001

Electron spin resonance characterization of the NAD(P)H oxidase in vascular smooth muscle cells.

Endogenously produced reactive oxygen species are important for intracellular signaling mechanisms leading to vascular smooth muscle cell (VSMC) growth. It is therefore critical to define the potential enzymatic sources of ROS and their regulation by agonists in VSMCs. Previous studies have investigated O2*- production using lucigenin-enhanced chemiluminescence. However, lucigenin has been recently criticized for its ability to redox cycle and its propensity to measure cellular reductase activity independent from O2*-. To perform a definitive characterization of VSMC oxidase activity, we used electron spin resonance trapping of O2*- with DEPMPO. We confirmed that the main source of O2*- from VSMC membranes is an NAD(P)H oxidase and that the O2*- formation from mitochondria, xanthine oxidase, arachidonate-derived enzymes, and nitric oxide synthases in VSMC membranes was minor. The VSMC NAD(P)H oxidase(s) are able to produce more O2*- when NADPH is used as the substrate compared to NADH (the maximal NADPH signal is 2.4- +/- 0.4-fold higher than the NADH signal). The two substrates had similar EC(50)'s ( approximately 10-50 microM). Stimulation with angiotensin II and platelet-derived growth factor also predominantly increased the NADPH-driven signal (101 +/- 8% and 83 +/- 1% increase above control, respectively), with less of an effect on NADH-dependent O2*- (17 +/- 3% and 36 +/- 5% increase, respectively). Moreover, incubation of the cells with diphenylene iodonium inhibited predominantly NADPH-stimulated O2*-. In conclusion, electron spin resonance characterization of VSMC oxidase activity supports a major role for an NAD(P)H oxidase in O2*- production in VSMCs, and provides new evidence concerning the substrate dependency and agonist-stimulated activity of this key enzyme.

Acridines↗