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I. S. Severina - One of the best experts on this subject based on the ideXlab platform.

  • Soluble Guanylate Cyclase in molecular mechanisms underlying the therapeutic action of drugs
    Biochemistry (Moscow) Supplement Series B: Biomedical Chemistry, 2012
    Co-Authors: N. V. Pyatakova, I. S. Severina
    Abstract:

    The influence of ambroxol (a mucolytic agent) on the activity of human platelet soluble Guanylate Cyclase and rat lung soluble Guanylate Cyclase and activation of both enzymes by NO-donors (sodium nitroprusside (SNP) and Sin-1) were investigated. Ambroxol in the range of concentrations from 0.1 to 10 μM had no effect on the basal activity of both enzymes. Ambroxol inhibited in a concentration-dependent manner the SNP-induced human platelet soluble Guanylate Cyclase and rat lung soluble Guanylate Cyclase with the IC_50 values of 3.9 and 2.1 μM, respectively. Ambroxol did not influence the stimulation of both enzymes by protoporphyrin IX. The influence of artemisinin (an antimalarial agent) on human platelet soluble Guanylate Cyclase activity and the enzyme activation by NO-donors were investigated. Artemisinin (0.1−100 μM) had no effect on the basal activity of the enzyme. Artemisinin inhibited in a concentration-dependent manner the SNP-induced activation of human platelet Guanylate Cyclase with the IC_50 value of 5.6 μM. Artemisinin (10 μM) also inhibited (by 71 ± 4.0%) the activation of the enzyme by a thiol-dependent NO-donor, the derivative of furoxan, 3,4-dicyano-1,2,5-oxadiazolo-2-oxide (10 μM), but did not influence the stimulation of soluble Guanylate Cyclase by protoporphyrin IX. It was concluded that the signaling system NO-soluble Guanylate Cyclase-cGMP is involved in the molecular mechanism of the therapeutic action of ambroxol and artemisinin.

  • Soluble Guanylate Cyclase in the molecular mechanism underlying the therapeutic action of drugs
    Biomeditsinskaia khimiia, 2012
    Co-Authors: N V Piatakova, I. S. Severina
    Abstract:

    The influence of ambroxol--a mucolytic drug--on the activity of human platelet soluble Guanylate Cyclase and rat lung soluble Guanylate Cyclase and activation of both enzymes by NO-donors (sodium nitroprusside and Sin-1) were investigated. Ambroxol in the concentration range from 0.1 to 10 microM had no effect on the basal activity of both enzymes. Ambroxol inhibited in a concentration-dependent manner the sodium nitroprusside-induced human platelet soluble Guanylate Cyclase and rat lung soluble Guanylate Cyclase with the IC50 values 3.9 and 2.1 microM, respectively. Ambroxol did not influence the stimulation of both enzymes by protoporphyrin IX. The influence of artemisinin--an antimalarial drug--on human platelet soluble Guanylate Cyclase activity and the enzyme activation by NO-donors were investigated. Artemisinin (0.1-100 microM) had no effect on the basal activity of the enzyme. Artemisinin inhibited in a concentration-dependent manner the sodium nitroprusside-induced activation of human platelet Guanylate Cyclase with an IC50 value 5.6 microM. Artemisinin (10 microM) also inhibited (by 71 +/- 4.0%) the activation of the enzyme by thiol-dependent NO-donor the derivative of furoxan, 3,4-dicyano-1,2,5-oxadiazolo-2-oxide (10 microM), but did not influence the stimulation of soluble Guanylate Cyclase by protoporphyrin IX. It was concluded that the sygnalling system NO-soluble Guanylate Cyclase-cGMP is involved in the molecular mechanism of the therapeutic action of ambroxol and artemisinin.

  • Potentiation of NO-dependent activation of soluble Guanylate Cyclase by polyamines
    Biochemistry (Moscow) Supplement Series B: Biomedical Chemistry, 2007
    Co-Authors: I. S. Severina, N. V. Pyatakova, A. Ya. Shchegolev
    Abstract:

    The influence of polyamines (putrescine, spermidine, and spermine) on the activity of human platelet soluble Guanylate Cyclase and the stimulation of the enzyme by sodium nitroprusside (SNP), YC-1 and their combination was investigated. All these polyamines stimulated the Guanylate Cyclase activity and potentiated its activation by sodium nitroprusside. The stimulatory effects of sodium nitroprusside and putrescine (or spermine) were addidive; spermidine produced a synergistic activation and increased the additive effect. All the polyamines inhibited the enzyme activation by YC-1 and decreased the synergistic activation of SNP-stimulated Guanylate Cyclase activity by YC-1 with nearly the same potency. The ability of the investigated polyamines to potentiate and to increase synergistically (similar to to YC-1, but less effective) NO-dependent activation of soluble Guanylate Cyclase represents a new biochemical effect of these compounds; this effect should be taken into consideration, especially due to the endogenous nature of polyamines. The data obtained suggest, that specific biological functions of polyamines in the processes of growth and differentiation of cells may be also related to the ability of compounds to activate soluble Guanylate Cyclase and to increase intracellular cGMP level.

  • Potentiation of NO-dependent activation of soluble Guanylate Cyclase by polyamines
    Biomeditsinskaia khimiia, 2007
    Co-Authors: I. S. Severina, N V Piatakova, A. Ya. Shchegolev
    Abstract:

    The influence of polyamines (putrescine, spermidine, spermine) on the activity of human platelet soluble Guanylate Cyclase and stimulation of the enzyme by sodium nitroprusside, YC-1 and their combination was investigated. All polyamines used stimulated the Guanylate Cyclase activity and potentiated its activation by sodium nitroprusside. The stimulatory effects of sodium nitroprusside and putrescine (or spermine) were additive; spermidine produced a synergistic activation and increased the additive effect. All polyamines investigated inhibited the activation of the enzyme by YC-1 and decreased the synergistic activation of sodium nitroprusside-stimulated Guanylate Cyclase activity by YC-1 with approximately the same efficiency. The revealed ability of polyamines investigated to potentiate and synergistically increase (similar to YC-1, but less effective) NO-dependent activation of soluble Guanylate Cyclase represents a new biochemical effect of these compounds, which should be taken into consideration, especially due to the endogenous nature of polyamines. The data obtained suggest, that the specific functions of polyamines in the processes of cell growth and diffentiation may be also related to the ability of these compounds to activate soluble Guanylate Cyclase and increase cGMP level.

  • Ambroxol as an inhibitor of nitric oxide-dependent activation of soluble Guanylate Cyclase.
    European journal of pharmacology, 2000
    Co-Authors: I. S. Severina, Olga G Bussygina, N. V. Pyatakova, Y V Khropov, R A Krasnoperov
    Abstract:

    The influence of ambroxol on the activity of human platelet soluble Guanylate Cyclase and rat lung soluble Guanylate Cyclase was investigated. Ambroxol in the concentration range from 0.1 to 10 microM had no effect on the basal activity of both enzymes and slightly enhanced it at 50 and 100 microM. Ambroxol inhibited in a concentration-dependent manner the sodium nitroprusside-induced activation of both enzymes. The IC(50) values for inhibition by ambroxol of sodium nitroprusside-stimulated human platelet soluble Guanylate Cyclase and rat lung soluble Guanylate Cyclase were 3.9 and 2.1 microM, respectively. Ambroxol did not influence the stimulation of soluble Guanylate Cyclase by protoporphyrin 1X. Thus, it is possible that the molecular mechanism of the therapeutic action of ambroxol involves the inhibition of nitric oxide (NO)-dependent activation of soluble Guanylate Cyclase.

Karl-wilhelm Koch - One of the best experts on this subject based on the ideXlab platform.

  • Target Recognition of Guanylate Cyclase By Guanylate Cyclase-Activating Proteins
    Advances in Experimental Medicine and Biology, 2002
    Co-Authors: Karl-wilhelm Koch
    Abstract:

    Guanylate Cyclase-activating proteins (GCAPs) control the activity of membrane bound Guanylate Cyclases in vertebrate photoreceptor cells. They form a permanent complex with Guanylate Cyclase 1 (ROS-GC1) at low and high Ca2+-concentrations. Five different target regions of GCAP-1 have been identified in ROS-GC1 at rather distant sites. These findings could indicate a multipoint attachment site for GCAP-1 or, alternatively, the presence of transient binding sites with short contact to GCAP-1. In addition some data are consistent with the operation of one or more transducer units, that represent regulatory regions without being direct binding sites. A permanent ROS-GCI/GCAP-1 complex is physiologically significant, since it allows a very short response time of Cyclase activity when the intracellular Ca2+-concentration changes. Thereby, activation of Cyclase participates in speeding up the recovery of the photoresponse after illumination and restores the circulating dark current.

  • Photoreceptor Guanylate Cyclase and Its Regulation by Calcium
    Signal Transduction in Photoreceptor Cells, 1992
    Co-Authors: Karl-wilhelm Koch, H. G. Lambrecht
    Abstract:

    Photoreceptor Guanylate Cyclase is highly sensitive to nanomolar calcium concentrations. This effect is mediated by a soluble regulatory protein. Guanylate Cyclase and its calcium dependent modulator protein have been purified from bovine rod outer segments and identified as a 112 kDa protein and a 26 kDa protein, respectively. Estimation of the molar quantities revealed that both proteins are present in equimolar amounts.

  • Purification and identification of photoreceptor Guanylate Cyclase.
    The Journal of biological chemistry, 1991
    Co-Authors: Karl-wilhelm Koch
    Abstract:

    Abstract Photoreceptor Guanylate Cyclase was solubilized and purified from bovine rod outer segments with 50-150-fold increase in specific activity using the nonionic detergent n-dodecyl-beta-D-maltoside. Guanylate Cyclase activities correlated with the enrichment of a protein with an apparent Mr = 112,000. The purified enzyme showed specific activities of 100-700 nmol of cGMP produced/min/mg protein and exhibited positive cooperativity with respect to MnGTP (Hill coefficient n = 1.6 +/- 0.1). The apparent Km was 274 +/- 67 microM, and the turnover number was determined to be 0.2-1.3 cGMP produced/s. The molar ratio of the 112-kDa protein to rhodopsin corresponds to 1:104. This indicates that the amount of Guanylate Cyclase in rod photoreceptors is nearly equimolar to the amount of the phosphodiesterase.

Chung-ho Chang - One of the best experts on this subject based on the ideXlab platform.

  • Proteolytic activation of membrane-bound Guanylate Cyclase
    Biochemical pharmacology, 2001
    Co-Authors: Zi-jiang Chen, Dong-li Song, Zhen-hua Miao, Chung-ho Chang
    Abstract:

    Abstract Membrane-bound Guanylate Cyclase-A (GC-A), the receptor for atrial natriuretic factor (ANF), has been shown to be regulated by its kinase-like domain. To resolve the nature of this regulation, we measured the effects of various proteases on the activity of Guanylate Cyclase in rat lung membranes, and on the activity of the bacterial-expressed catalytic domain (GC-c) and on a recombinant peptide composed of both the kinase-like and catalytic domain (GC-kc) of Guanylate Cyclase. Pronase increased rat Guanylate Cyclase activity in a biphasic manner with a maximal effect at about 10–20 μg per assay tube. Thermolysin had effects similar to those of pronase on the activity of Guanylate Cyclase in rat lung membranes. In the case of bacterial-expressed proteins, pronase increased the activity of GC-kc, but not GC-c. These results indicate that GC-A contains an autoinhibitory site on its kinase-like domain, and that removal of the autoinhibitory site by limited proteolysis leads to enzyme activation. GC-A was poorly activated by ANF and ATP after the rat lung membrane was pretreated with pronase, suggesting that ANF/ATP and pronase activate Guanylate Cyclase through the same mechanism. It is suggested that the binding of ANF and ATP to GC-A may induce a conformational change of the receptor that releases the inhibitory constraint on enzyme activity leading to enzyme activation.

  • Resveratrol Activates Membrane‐bound Guanylate Cyclase in PC12 Cells
    Pharmacy and Pharmacology Communications, 2000
    Co-Authors: Zi-jiang Chen, Danian Che, Chung-ho Chang
    Abstract:

    Resveratrol, found in wine and grapes, has cardioprotective and anticarcinogenic properties. The Guanylate Cyclase-cyclic GMP (cGMP) system is known to mediate the effects of vasoactive hormone and ligands such as atrial natriuretic factor and nitric oxide. It is possible that resveratrol exerts its effects by activating Guanylate Cyclase. This study was conducted to examine whether resveratrol can affect the Guanylate Cyclase-cGMP system in PC12 cells. The results showed that resveratrol dose-dependently increased cGMP levels. It inhibited membrane-bound Guanylate Cyclase activity stimulated by atrial natriuretic factor, but had no effect on soluble Guanylate Cyclase activity stimulated by sodium nitroprusside. It also directly stimulated membrane-bound Guanylate Cyclase activity in PC12 cell membranes. These results show that resveratrol increases cGMP formation by activating membrane-bound, but not soluble, Guanylate Cyclase.

  • Mutational Inactivation of the Catalytic Domain of Guanylate Cyclase-A Receptor
    Hypertension, 1995
    Co-Authors: Zhen-hua Miao, Dong-li Song, Janice G. Douglas, Chung-ho Chang
    Abstract:

    Abstract Guanylate Cyclase-A, the receptor for atrial natriuretic factor, contains a protein kinase–like domain and a catalytic domain in the intracellular region. To investigate the active site (the catalytic cavity) of Guanylate Cyclase-A, we amplified the catalytic domain plus three amino acids from the kinase-like domain of Guanylate Cyclase-A (GC-c) with polymerase chain reaction (PCR) and expressed it in Escherichia coli . During the screening of the PCR-cloned gene products with Guanylate Cyclase assay, a mutant that lacks enzyme activity was identified. Results of cDNA sequencing revealed that Leu 817 was replaced by an Arg residue in the mutated protein. The mutated GC-c bound to GTP-agarose as well as the wild-type protein, indicating that the binding capability of mutated GC-c to GTP is not significantly affected by the Arg substitution. Gel-filtration column chromatography showed that, like the wild-type GC-c, the mutated protein also formed a high-molecular-weight complex. Since mutation of Leu 817 to Arg abolishes the catalytic activity, Leu 817 is likely located near the active site of Guanylate Cyclase-A. These results demonstrate that the carboxyl fragment of Guanylate Cyclase-A is an ideal system for studying the active site of Guanylate Cyclase-A.

  • Melittin potentiates Guanylate Cyclase activation stimulated by atrial natriuretic factor and ATP.
    The Journal of biological chemistry, 1993
    Co-Authors: Chung-ho Chang, Dong-li Song
    Abstract:

    Abstract The biologically relevant receptor for atrial natriuretic factor (ANF) has been shown to be membrane-bound Guanylate Cyclase. While Guanylate Cyclase is known to be activated by ANF and ATP, the molecular mechanism of the enzyme activation remains unclear. We now show that melittin, the main peptide toxin of bee venom, activates membrane-bound Guanylate Cyclase and potentiates ANF- and ATP-stimulated Guanylate Cyclase activity in rat lung membranes. Melittin stimulated basal Guanylate Cyclase activity by increasing the Vmax without significantly affecting the Km of the substrate, GTP. However, melittin enhances ANF- and ATP-stimulated enzyme activity by altering both the Vmax and the EC50 of ANF and ATP. Although melittin activates Guanylate Cyclase in crude membranes, it has little effect on the activity of the purified enzyme. The effect of melittin on Guanylate Cyclase activation in rat lung membranes is attenuated by the Ca2+ chelator, EGTA. These results suggest that the effects of melittin on Guanylate Cyclase activation may require the participation of accessory proteins or nonprotein factors. Therefore, melittin would be a valuable tool for exploring the molecular mechanisms of ANF-mediated Guanylate Cyclase activation.

Dong-li Song - One of the best experts on this subject based on the ideXlab platform.

  • Proteolytic activation of membrane-bound Guanylate Cyclase
    Biochemical pharmacology, 2001
    Co-Authors: Zi-jiang Chen, Dong-li Song, Zhen-hua Miao, Chung-ho Chang
    Abstract:

    Abstract Membrane-bound Guanylate Cyclase-A (GC-A), the receptor for atrial natriuretic factor (ANF), has been shown to be regulated by its kinase-like domain. To resolve the nature of this regulation, we measured the effects of various proteases on the activity of Guanylate Cyclase in rat lung membranes, and on the activity of the bacterial-expressed catalytic domain (GC-c) and on a recombinant peptide composed of both the kinase-like and catalytic domain (GC-kc) of Guanylate Cyclase. Pronase increased rat Guanylate Cyclase activity in a biphasic manner with a maximal effect at about 10–20 μg per assay tube. Thermolysin had effects similar to those of pronase on the activity of Guanylate Cyclase in rat lung membranes. In the case of bacterial-expressed proteins, pronase increased the activity of GC-kc, but not GC-c. These results indicate that GC-A contains an autoinhibitory site on its kinase-like domain, and that removal of the autoinhibitory site by limited proteolysis leads to enzyme activation. GC-A was poorly activated by ANF and ATP after the rat lung membrane was pretreated with pronase, suggesting that ANF/ATP and pronase activate Guanylate Cyclase through the same mechanism. It is suggested that the binding of ANF and ATP to GC-A may induce a conformational change of the receptor that releases the inhibitory constraint on enzyme activity leading to enzyme activation.

  • Mutational Inactivation of the Catalytic Domain of Guanylate Cyclase-A Receptor
    Hypertension, 1995
    Co-Authors: Zhen-hua Miao, Dong-li Song, Janice G. Douglas, Chung-ho Chang
    Abstract:

    Abstract Guanylate Cyclase-A, the receptor for atrial natriuretic factor, contains a protein kinase–like domain and a catalytic domain in the intracellular region. To investigate the active site (the catalytic cavity) of Guanylate Cyclase-A, we amplified the catalytic domain plus three amino acids from the kinase-like domain of Guanylate Cyclase-A (GC-c) with polymerase chain reaction (PCR) and expressed it in Escherichia coli . During the screening of the PCR-cloned gene products with Guanylate Cyclase assay, a mutant that lacks enzyme activity was identified. Results of cDNA sequencing revealed that Leu 817 was replaced by an Arg residue in the mutated protein. The mutated GC-c bound to GTP-agarose as well as the wild-type protein, indicating that the binding capability of mutated GC-c to GTP is not significantly affected by the Arg substitution. Gel-filtration column chromatography showed that, like the wild-type GC-c, the mutated protein also formed a high-molecular-weight complex. Since mutation of Leu 817 to Arg abolishes the catalytic activity, Leu 817 is likely located near the active site of Guanylate Cyclase-A. These results demonstrate that the carboxyl fragment of Guanylate Cyclase-A is an ideal system for studying the active site of Guanylate Cyclase-A.

  • Melittin potentiates Guanylate Cyclase activation stimulated by atrial natriuretic factor and ATP.
    The Journal of biological chemistry, 1993
    Co-Authors: Chung-ho Chang, Dong-li Song
    Abstract:

    Abstract The biologically relevant receptor for atrial natriuretic factor (ANF) has been shown to be membrane-bound Guanylate Cyclase. While Guanylate Cyclase is known to be activated by ANF and ATP, the molecular mechanism of the enzyme activation remains unclear. We now show that melittin, the main peptide toxin of bee venom, activates membrane-bound Guanylate Cyclase and potentiates ANF- and ATP-stimulated Guanylate Cyclase activity in rat lung membranes. Melittin stimulated basal Guanylate Cyclase activity by increasing the Vmax without significantly affecting the Km of the substrate, GTP. However, melittin enhances ANF- and ATP-stimulated enzyme activity by altering both the Vmax and the EC50 of ANF and ATP. Although melittin activates Guanylate Cyclase in crude membranes, it has little effect on the activity of the purified enzyme. The effect of melittin on Guanylate Cyclase activation in rat lung membranes is attenuated by the Ca2+ chelator, EGTA. These results suggest that the effects of melittin on Guanylate Cyclase activation may require the participation of accessory proteins or nonprotein factors. Therefore, melittin would be a valuable tool for exploring the molecular mechanisms of ANF-mediated Guanylate Cyclase activation.

Scott A. Waldman - One of the best experts on this subject based on the ideXlab platform.

  • Adenine nucleotide regulation of particulate Guanylate Cyclase from rat lung
    Biochimica et Biophysica Acta, 1991
    Co-Authors: Helene Gazzano, H.irene Wu, Scott A. Waldman
    Abstract:

    Abstract Adenine nucleotides activate basal particulate Guanylate Cyclase in rat lung membranes. Activation is specific for adenine and not guanine, cytidine or uridine nucleotides. The concentration of adenine nucleotides yielding half-maximum activation of particulate Guanylate Cyclase is 0.1 mM and this nucleotide activates the enzyme by increasing maximum velocity 11-fold without altering affinity for substrate. Activation is specific for particulate Guanylate Cyclase, since soluble enzyme is inhibited by adenine nucleotides. Similarly, activation is specific for magnesium as the enzyme substrate cation cofactor, since adenine nucleotides inhibit particulate Guanylate Cyclase when manganese is used. Adenine nucleotide regulation of particulate Guanylate Cyclase may occur by a different molecular mechanism compared to other activators, since the effects of these nucleotides are synergistic with those of detergent, hemin and atrial natriuretic peptides. Cystamine inhibits adenine nucleotide activation of particulate Guanylate Cyclase at concentrations having minimal effects on basal enzyme activity suggesting a role for critical sulfhydryls in mechanisms underlying nucleotide regulation of particulate Guanylate Cyclase. Purification and quantitative recovery of particulate Guanylate Cyclase by substrate affinity chromatography results in the loss of adenine nucleotide regulation. These data suggest that adenine nucleotides may be important in the regulation of basal and activated particulate Guanylate Cyclase and may be mediated by an adenine nucleotide-binding protein which is separate from that enzyme.