The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
Lanfranco Masotti - One of the best experts on this subject based on the ideXlab platform.
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Conformational Changes of Neuromedin b and delta sleep induCing peptide induCed by their interaCtion with lipid membranes as revealed by speCtrosCopiC teChniques and moleCular dynamiCs simulation
Archives of Biochemistry and Biophysics, 1998Co-Authors: Eugenia Polverini, Paolo Neyroz, Rita Casadio, Lanfranco MasottiAbstract:StatiC and dynamiC speCtrosCopiC properties of the tryptophanil emission in ConjunCtion with CirCular diChroism (CD) speCtrosCopy and moleCular dynamiCs are used to investigate the interaCtions of the neuropeptide Neuromedin B (NMB) and the membrane-permeable delta sleep-induCing peptide (DSIP) with the membrane lipid phase. Our data indiCate that in solution both peptides exist in energetiCally equivalent Conformations, whereas in the presenCe of the membrane speCifiC Conformational states are stabilized. By Changing from the aqueous to the lipid phase, the statiC and the dynamiC fluoresCenCe properties of the NMB's tryptophan residue are Clearly affeCted: the fluoresCenCe steady-state speCtrum as well as the resolved fluoresCenCe deCay-assoCiated speCtra (DAS) are shifted to the blue with a signifiCant inCrease of the fluoresCenCe intensity of the seCond lifetime Component (tau 2-DAS). On the other hand, in the lipid environment the same parameters of DSIP are negligibly affeCted as Compared to the aqueous buffer. The CD and moleCular dynamiCs analyses are Consistent with these results and indiCate that, while NMB assumes a helix-like Conformation with the tryptophan residue in the apolar surfaCe, DSIP adopts a globule-like struCture with the indole ring that is surfaCe-exposed. As previously found for Neuromedin C (Polverini, E., Neyroz, P., Fariselli, P., Casadio, R., and Masotti, L., BioChem. Biophys. Res. Commun. 214, 663-668, 1995), for NMB the stabilized "lipophiliC" struCture also may favor the CorreCt peptide-reCeptor ContaCt and reCognition. For DSIP, the lipid-stabilized Conformation does not support an amphiphiliC struCture-driven peptide-membrane interaCtion and suggests a hydrophobiCity-driven diffusion aCross the bilayer.
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the effeCt of membranes on the Conformation of Neuromedin C
Biochemical and Biophysical Research Communications, 1995Co-Authors: Eugenia Polverini, Paolo Neyroz, Piero Fariselli, Rita Casadio, Lanfranco MasottiAbstract:AbstraCt The Combination of statiC and dynamiC speCtrosCopy data with the information obtained by Computational methods has been used to investigate the Conformation of Neuromedin C in the absenCe and in the presenCe of lipid membranes. Upon addition of lipids, the peptide steady-state emission speCtrum is blue shifted (355 nm vs 345 nm) and all the reCovered fluoresCenCe deCay Constants are signifiCantly longer. CD measurements show that fluoresCenCe Changes are Consistent with α-helix induCing struCtural transitions. MoleCular dynamiCs studies show that, in solution, the peptide Conformation rapidly exChanges between energetiCally equivalent disordered and ordered states, whereas, in the presenCe of membrane, the peptide Conformation is stabilized in an ordered state.
Monica De La Fuente - One of the best experts on this subject based on the ideXlab platform.
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ChemoattraCtant CapaCity of bombesin gastrin releasing peptide and Neuromedin C is mediated through pkC aCtivation in murine peritoneal leukoCytes
Regulatory Peptides, 1994Co-Authors: Monica Del Rio, Monica De La FuenteAbstract:AbstraCt Bombesin-like peptides have been reCently shown to regulate immune funCtions. In the present work, we have studied their aCtion as ChemoattraCtants for murine peritoneal maCrophages and lymphoCytes. The results showed a signifiCant inCrease in the number of Cells that migrate when they are exposed to a gradient of bombesin, gastrin-releasing peptide (GRP) or Neuromedin C (from 10 −8 to 10 −12 M). The most effeCtive of the three neuropeptides studied was GRP, even more than formyl-Met-Leu-Phe peptide (FMLP), an established leukoCyte ChemoattraCtant. GRP aCtion was mediated through speCifiC Cell reCeptors as it was signifiCantly reduCed in presenCe of a Competitive and speCifiC bombesin reCeptor antagonist. In the presenCe of retinal, a protein kinase C (PKC) inhibitor, the ChemoattraCtant CapaCity of GRP was Considerably reduCed. In order to investigate further the meChanism of aCtion involved in the GRP effeCt, we measured PKC aCtivity. Peritoneal Cells inCubated with GRP experimented an inCrease in PKC aCtivity to the same extent of that produCed by the PKC aCtivator phorbol myristate aCetate (PMA). These data prove that bombesin-like peptides are potent ChemoattraCtants for murine peritoneal maCrophages and lymphoCytes, and that their aCtion is at least in part mediated through PKC aCtivation.
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bombesin gastrin releasing peptide and Neuromedin C modulate murine lymphoCyte proliferation through adherent aCCessory Cells and aCtivate protein kinase C
Peptides, 1994Co-Authors: Monica Del Rio, Angel Hernanz, Monica De La FuenteAbstract:AbstraCt ReCent data have shown the ability of bombesin-related peptides to stimulate murine maCrophage funCtions. In the present study, we have investigated the effeCt of bombesin, gastrin-releasing peptide (GRP), and Neuromedin C on the proliferative response of lymphoCytes from murine axillary nodes, spleen, and thymus. The results show that these neuropeptides at 10 −9 , 10 −10 , and 10 −11 M ConCentrations modulate the lymphoproliferative response, stimulating to a small but signifiCant extent the spontaneous proliferation and inhibiting to a great extent the lymphoproliferative response to the mitogen ConCanavalin A (Con A). This regulation is probably mediated through adherent aCCessory Cells, sinCe their presenCe is neCessary for the neuropeptides to produCe their effeCt. The inCreased interleukin-1β produCtion by Con A in Cultures of peritoneal maCrophages (a model of adherent aCCessory Cells) deCreased after the addition of bombesin, GRP, and Neuromedin C; this diminution is a possible meChanism for their inhibitory aCtion on the lymphoproliferative response to Con A. In addition, these neuropeptides Caused a signifiCant protein kinase C aCtivation in total leukoCyte population and T-enriChed lymphoCytes from axillary nodes, as well as in peritoneal maCrophages.
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stimulation of natural killer and antibody dependent Cellular CytotoxiCity aCtivities in mouse leukoCytes by bombesin gastrin releasing peptide and Neuromedin C involvement of CyCliC amp inositol 1 4 5 trisphosphate and protein kinase C
Journal of Neuroimmunology, 1993Co-Authors: Monica De La Fuente, Monica Del Rio, Angel HernanzAbstract:AbstraCt Bombesin and the two mammalian bombesin-related peptides, gastrin-releasing peptide (GRP) and Neuromedin C, at physiologiCal ConCentrations ranging from 10−11 M to 10−9 M have been shown in this study to signifiCantly stimulate in vitro the antibody-dependent Cellular CytotoxiCity (ADCC) and natural killer (NK) aCtivities in BALB/C mouse leukoCytes from axillary nodes, spleen and thymus. The three neuropeptides studied induCed no Change in interleukin-2 produCtion. In addition, these neuropeptides induCed in leukoCytes from axillary nodes a rapid, transient and signifiCant deCrease of intraCellular CyCliC AMP at 30 s, but a signifiCant transient inCrease of inositol 1,4,5-trisphosphate levels at 30 and 60 s and a stimulation of protein kinase C aCtivity in membrane fraCtions after 5 min inCubation. These results suggest that inositol phospholipid signalling and CAMP messenger systems are involved in the inCrease of NK and ADCC aCtivities when leukoCytes are inCubated in the presenCe of bombesin, GRP or Neuromedin C.
Eugenia Polverini - One of the best experts on this subject based on the ideXlab platform.
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Conformational Changes of Neuromedin b and delta sleep induCing peptide induCed by their interaCtion with lipid membranes as revealed by speCtrosCopiC teChniques and moleCular dynamiCs simulation
Archives of Biochemistry and Biophysics, 1998Co-Authors: Eugenia Polverini, Paolo Neyroz, Rita Casadio, Lanfranco MasottiAbstract:StatiC and dynamiC speCtrosCopiC properties of the tryptophanil emission in ConjunCtion with CirCular diChroism (CD) speCtrosCopy and moleCular dynamiCs are used to investigate the interaCtions of the neuropeptide Neuromedin B (NMB) and the membrane-permeable delta sleep-induCing peptide (DSIP) with the membrane lipid phase. Our data indiCate that in solution both peptides exist in energetiCally equivalent Conformations, whereas in the presenCe of the membrane speCifiC Conformational states are stabilized. By Changing from the aqueous to the lipid phase, the statiC and the dynamiC fluoresCenCe properties of the NMB's tryptophan residue are Clearly affeCted: the fluoresCenCe steady-state speCtrum as well as the resolved fluoresCenCe deCay-assoCiated speCtra (DAS) are shifted to the blue with a signifiCant inCrease of the fluoresCenCe intensity of the seCond lifetime Component (tau 2-DAS). On the other hand, in the lipid environment the same parameters of DSIP are negligibly affeCted as Compared to the aqueous buffer. The CD and moleCular dynamiCs analyses are Consistent with these results and indiCate that, while NMB assumes a helix-like Conformation with the tryptophan residue in the apolar surfaCe, DSIP adopts a globule-like struCture with the indole ring that is surfaCe-exposed. As previously found for Neuromedin C (Polverini, E., Neyroz, P., Fariselli, P., Casadio, R., and Masotti, L., BioChem. Biophys. Res. Commun. 214, 663-668, 1995), for NMB the stabilized "lipophiliC" struCture also may favor the CorreCt peptide-reCeptor ContaCt and reCognition. For DSIP, the lipid-stabilized Conformation does not support an amphiphiliC struCture-driven peptide-membrane interaCtion and suggests a hydrophobiCity-driven diffusion aCross the bilayer.
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the effeCt of membranes on the Conformation of Neuromedin C
Biochemical and Biophysical Research Communications, 1995Co-Authors: Eugenia Polverini, Paolo Neyroz, Piero Fariselli, Rita Casadio, Lanfranco MasottiAbstract:AbstraCt The Combination of statiC and dynamiC speCtrosCopy data with the information obtained by Computational methods has been used to investigate the Conformation of Neuromedin C in the absenCe and in the presenCe of lipid membranes. Upon addition of lipids, the peptide steady-state emission speCtrum is blue shifted (355 nm vs 345 nm) and all the reCovered fluoresCenCe deCay Constants are signifiCantly longer. CD measurements show that fluoresCenCe Changes are Consistent with α-helix induCing struCtural transitions. MoleCular dynamiCs studies show that, in solution, the peptide Conformation rapidly exChanges between energetiCally equivalent disordered and ordered states, whereas, in the presenCe of membrane, the peptide Conformation is stabilized in an ordered state.
Monica Del Rio - One of the best experts on this subject based on the ideXlab platform.
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ChemoattraCtant CapaCity of bombesin gastrin releasing peptide and Neuromedin C is mediated through pkC aCtivation in murine peritoneal leukoCytes
Regulatory Peptides, 1994Co-Authors: Monica Del Rio, Monica De La FuenteAbstract:AbstraCt Bombesin-like peptides have been reCently shown to regulate immune funCtions. In the present work, we have studied their aCtion as ChemoattraCtants for murine peritoneal maCrophages and lymphoCytes. The results showed a signifiCant inCrease in the number of Cells that migrate when they are exposed to a gradient of bombesin, gastrin-releasing peptide (GRP) or Neuromedin C (from 10 −8 to 10 −12 M). The most effeCtive of the three neuropeptides studied was GRP, even more than formyl-Met-Leu-Phe peptide (FMLP), an established leukoCyte ChemoattraCtant. GRP aCtion was mediated through speCifiC Cell reCeptors as it was signifiCantly reduCed in presenCe of a Competitive and speCifiC bombesin reCeptor antagonist. In the presenCe of retinal, a protein kinase C (PKC) inhibitor, the ChemoattraCtant CapaCity of GRP was Considerably reduCed. In order to investigate further the meChanism of aCtion involved in the GRP effeCt, we measured PKC aCtivity. Peritoneal Cells inCubated with GRP experimented an inCrease in PKC aCtivity to the same extent of that produCed by the PKC aCtivator phorbol myristate aCetate (PMA). These data prove that bombesin-like peptides are potent ChemoattraCtants for murine peritoneal maCrophages and lymphoCytes, and that their aCtion is at least in part mediated through PKC aCtivation.
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bombesin gastrin releasing peptide and Neuromedin C modulate murine lymphoCyte proliferation through adherent aCCessory Cells and aCtivate protein kinase C
Peptides, 1994Co-Authors: Monica Del Rio, Angel Hernanz, Monica De La FuenteAbstract:AbstraCt ReCent data have shown the ability of bombesin-related peptides to stimulate murine maCrophage funCtions. In the present study, we have investigated the effeCt of bombesin, gastrin-releasing peptide (GRP), and Neuromedin C on the proliferative response of lymphoCytes from murine axillary nodes, spleen, and thymus. The results show that these neuropeptides at 10 −9 , 10 −10 , and 10 −11 M ConCentrations modulate the lymphoproliferative response, stimulating to a small but signifiCant extent the spontaneous proliferation and inhibiting to a great extent the lymphoproliferative response to the mitogen ConCanavalin A (Con A). This regulation is probably mediated through adherent aCCessory Cells, sinCe their presenCe is neCessary for the neuropeptides to produCe their effeCt. The inCreased interleukin-1β produCtion by Con A in Cultures of peritoneal maCrophages (a model of adherent aCCessory Cells) deCreased after the addition of bombesin, GRP, and Neuromedin C; this diminution is a possible meChanism for their inhibitory aCtion on the lymphoproliferative response to Con A. In addition, these neuropeptides Caused a signifiCant protein kinase C aCtivation in total leukoCyte population and T-enriChed lymphoCytes from axillary nodes, as well as in peritoneal maCrophages.
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stimulation of natural killer and antibody dependent Cellular CytotoxiCity aCtivities in mouse leukoCytes by bombesin gastrin releasing peptide and Neuromedin C involvement of CyCliC amp inositol 1 4 5 trisphosphate and protein kinase C
Journal of Neuroimmunology, 1993Co-Authors: Monica De La Fuente, Monica Del Rio, Angel HernanzAbstract:AbstraCt Bombesin and the two mammalian bombesin-related peptides, gastrin-releasing peptide (GRP) and Neuromedin C, at physiologiCal ConCentrations ranging from 10−11 M to 10−9 M have been shown in this study to signifiCantly stimulate in vitro the antibody-dependent Cellular CytotoxiCity (ADCC) and natural killer (NK) aCtivities in BALB/C mouse leukoCytes from axillary nodes, spleen and thymus. The three neuropeptides studied induCed no Change in interleukin-2 produCtion. In addition, these neuropeptides induCed in leukoCytes from axillary nodes a rapid, transient and signifiCant deCrease of intraCellular CyCliC AMP at 30 s, but a signifiCant transient inCrease of inositol 1,4,5-trisphosphate levels at 30 and 60 s and a stimulation of protein kinase C aCtivity in membrane fraCtions after 5 min inCubation. These results suggest that inositol phospholipid signalling and CAMP messenger systems are involved in the inCrease of NK and ADCC aCtivities when leukoCytes are inCubated in the presenCe of bombesin, GRP or Neuromedin C.
Miquel Adrover - One of the best experts on this subject based on the ideXlab platform.
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understanding metal binding in Neuromedin C
Inorganica Chimica Acta, 2020Co-Authors: Ana Belen Uceda, Miquel Adrover, Laura Marino, Bartolome VilanovaAbstract:AbstraCt Neuromedin C (NMC) is an endogenous bombesine-like peptide that is present mainly in the Central nervous system (CNS) and the gastrointestinal traCt. In addition to its biologiCal funCtion as a neuropeptide, NMC aCts as a growth faCtor for some tumours and plays a major role in transition metal homeostasis in the CNS. In this work, we determined the binding Constants and main thermodynamiC parameters for the Complexes of NMC with Cu2+, Ni2+ and Co2+ ions. The binding Constants obtained were Consistent with the Irving–Williams series, where the affinity for transition metal Cations inCreases aCross the periodiC table. All NMC Complexes had a positive enthalpy (ΔH > 0), whiCh is Consistent with an entropy-driven proCess. The affinity of NMC for Cu2+ and Ni2+ was similar to that of other peptides also Containing the ATCUN motif. However, the low ConCentrations of NMC in serum suggest that the peptide is unlikely to play a biologiCal role in metal homeostasis in the CNS or the gastrointestinal traCt.
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Conformational ensembles of Neuromedin C reveal a progressive Coil helix transition within a binding induCed folding meChanism
RSC Advances, 2015Co-Authors: Miquel Adrover, Pilar Sanchis, Bartolome Vilanova, Kris Pauwels, Gabriel Martorell, Juan J PerezAbstract:Neuromedin C (NMC) is a peptide that regulates various proCesses in the Central nervous system and gastrointestinal traCt through its interaCtion with the bombesin reCeptor subtype-2 (BB2R). HenCe, BB2R antagonists hold the potential to treat disorders that oCCur as a result of NMC dysfunCtion or misregulation. However, their effiCient design requires a detailed understanding of the struCtural features of NMC, whiCh hitherto are unknown. Herein, we desCribe the Conformational ensembles of NMC in an aqueous solution, at five different TFE ConCentrations to deCode its folding pathway and under its SDS miCelle bound state. NMC displays a disordered but well defined baCkbone arChiteCture that undergoes a progressive Coil-helix transition with inCreasing TFE ConCentration, first at the C-terminus and then at the N-terminus. NMC also adopts a C-terminal α-heliCal Conformation upon binding to SDS miCelles. This miCelle binding is direCted by hydrophobiC interaCtions that ConCur with the unfavourable deprotonation of His8 and its further insertion into the miCelle. Moreover, NMR relaxation data reveal that the aCquisition of the miCelle bound α-heliCal Conformation Constrains the NMC flexibility more than the Confinement itself. This Comprehensive study of the struCtural behaviour of NMC provides essential meChanistiC information that Could be useful for the development of new therapeutiCs to treat neurologiCal, CanCer-related or eating disorders.