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1.
Magn Reson Imaging ; 56: 86-89, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30336200

RESUMO

We have applied diffusion and relaxation Nuclear Magnetic Resonance experiments to investigate the translational and rotational mobility of adsorbents on quartz and calcite mineral surfaces. On both surfaces it was found that water is the dominant molecule. On the quartz surface the majority of water molecules have a relatively high degree of both rotational and translational mobility, while a minor fraction of water molecules, and all hydrocarbon molecules, have a significantly lower mobility. On the calcite surface the translational mobility is very low for all the adsorbed molecules, while there is a large diversity in rotational mobility, indicating that the hydrocarbon molecules are strongly attached to the surface, but that some part of each molecule still have a large degree of rotational mobility. Diffusion and relaxation experiments give a detailed description of both the molecular mobility of adsorbed species on these mineral surfaces, which leads to new insight with respect to aging processes on a molecular level.


Assuntos
Hidrocarbonetos/química , Espectroscopia de Ressonância Magnética/métodos , Minerais/química , Petróleo , Água/química , Adsorção , Difusão , Imageamento por Ressonância Magnética , Pós , Quartzo/química , Rotação , Software
2.
Environ Sci Technol ; 50(15): 8290-5, 2016 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-27379686

RESUMO

Coplanar and noncoplanar polychlorinated biphenyls (PCBs) are known to have different routes and degree of toxicity. Here, the effects of noncoplanar PCB 52 and coplanar PCB 77 present at 2 mol % in a model system consisting of POPC liposomes (50% hydrated) are investigated by solid-state (13)C and (31)P NMR at 298 K. Both PCBs intercalate horizontally in the outer part of the bilayer, near the segments of the acyl chain close to the glycerol group. Despite similar membrane locations, the coplanar PCB 77 shows little effect on the bilayer properties overall, except for the four nearest neighboring lipids, while the effect of PCB 52 is more dramatic. The first ∼2 layers of lipids around each PCB 52 in the bilayer form a high fluidity lamellar phase, whereas lipids beyond these layers form a lamellar phase with a slight increase in fluidity compared to a bilayer without PCB 52. Further, a third high mobility domain is observed. The explanation for this is the interference of several high fluidity lamellar phases caused by interactions of PCB 52 molecules in different leaflets of the model bilayer. This causes formation of high curvature toroidal region in the bilayer and might induce formation of channels.


Assuntos
Bicamadas Lipídicas , Bifenilos Policlorados
3.
Biophys Chem ; 207: 74-81, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26408828

RESUMO

The interaction of coenzyme Q10 (CoQ10) in a monolayer of 1,2-dipalmitoyl-sn-glysero-3-phospho-L-choline (DPPC), in a monolayer of 1,2-dierucoyl-sn-glysero-3-phospho-L-choline (DEPC), in a monolayer of 1-palmitoyl-2-oleoyl-sn-glysero-3-phospho-L-serine (POPS) and in a monolayer of total lipid extract from pig brain (PB) has been investigated by using the Langmuir monolayer technique. Surface pressure (π)-mean molecular area (mma) isotherms have been measured for pure lipid monolayers and lipid monolayers with 0.5, 1.0, 2.0, 5.0 and 10.0 mol% CoQ10 concentrations. At the biological concentration (1.0-3.0 mol%) of CoQ10, intercalation of CoQ10 occurs in the lipid acyl chains of DPPC, POPS and PB monolayers. Above the biological concentration of CoQ10, the CoQ10 molecule induces domain formation in the monolayers of DPPC, POPS and PB lipids. The DEPC monolayer behavior deviates from the other lipids in this study. At 2.0 mol% the CoQ10 promotes very dense lipid packing, and the CoQ10 molecule is located parallel to the DEPC acyl chains at all concentrations.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Fosfatidilserinas/química , Ubiquinona/análogos & derivados , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Animais , Encéfalo/metabolismo , Fosfatidilserinas/metabolismo , Propriedades de Superfície , Suínos , Ubiquinona/química , Ubiquinona/metabolismo
4.
Langmuir ; 29(35): 11055-61, 2013 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-23937632

RESUMO

Thin films of water between glass plates were investigated in this study with regard to water structure and dynamics in the temperature range of 278-313 K. We further investigated how addition of 1-butanol (0.05 and 0.5 M) affects the range and properties of the surface-induced water structures. From the observation of two (1)H nuclear magnetic resonance (NMR) water resonances and two relaxation components, it was found that the interfacial water exists in a two-state mixture in dynamic equilibrium, with the respective structures interpreted as being high-density water (HDW) and low-density water (LDW). In the absence of 1-butanol, the LDW state is more pronounced, with a further shift in equilibrium toward the LDW state with an increase in temperature. However, in water film samples containing 1-butanol, the HDW state dominates at low temperatures while the LDW state becomes more visible at higher temperatures. Furthermore, the addition of 1-butanol significantly increased the extent of the surface-induced water structures. NMR relaxation shows that the dynamics of water in the HDW state is significantly affected by the presence of 1-butanol and further indicates that the distribution of values for the enthalpy of activation associated with translational motion of water molecules in the HDW state is narrower in the 0.05 M 1-butanol sample than in the 0.5 M 1-butanol sample.

5.
Eur J Pharm Sci ; 47(2): 394-401, 2012 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-22750081

RESUMO

The interactions of the racemic mixture of articaine as well as pure (R)-articaine and pure (S)-articaine with monolayers of glycerophospholipids and brain lipids have been studied using the Langmuir monolayer technique. Articaine was added to the glycerophospholipids dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylserine (DPPS), 1-palmitoyl-2-oleoylphosphatidylserine (POPS) and total lipid extract from pig brain (TLPB). The amount of articaine in the monolayers was 30 mol%. The intercalation of each of the two enantiomers of articaine into a glycerophospholipid/brain lipid monolayers composed of chiral phospholipids will be diastereoisomeric in nature, hence different intercalation pattern for the two enantiomers can be expected. All the articaine species are found to intercalate into the DPPC monolayer and to increase the monolayer stability, this is most pronounced for the (R)-enantiomer. Intercalation of the articaine species into the DPPS monolayer increases the MMA and hardly affects the stability of the DPPS monolayer. In this monolayer, the articaine species intercalates into the head group region of the small and negatively charged serine head group, this is pronounced for the (R)-enantiomer. Our results indicate that by introducing an unsaturated acyl chain in the monolayer as in POPS, the monolayer discriminates between the articaine species. The (R)-enantiomer is located deep in the acyl chain region, whereas the (S)-enantiomer is found at or close to the head group. The data also might indicate that the (R)-enantiomer in the racemic mixture forms dimers in the POPS monolayer. Both articaine species as well as the racemic mixture intercalate into the monolayer of TLPB. Intercalation into this monolayer did not show any distinct difference in intercalation mode of the articaine species, probably due to camouflaging effect of large head groups like gangliosides and/or formation of lipid rafts in the monolayer. However, the (R)-enantiomer appears to intercalate better into the TLPB monolayer than the (S)-enantiomer. With proper standardization the Langmuir monolayer technique is a powerful method to discriminate between (R)- and (S)-enantiomer articaine interaction with model membranes.


Assuntos
Anestésicos Locais/metabolismo , Carticaína/metabolismo , Metabolismo dos Lipídeos , Anestésicos Locais/química , Animais , Encéfalo/metabolismo , Carticaína/química , Membrana Celular/metabolismo , Fosfatidilserinas/metabolismo , Fosforilcolina/metabolismo , Estereoisomerismo , Suínos
6.
Langmuir ; 28(16): 6569-76, 2012 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-22462515

RESUMO

Knowledge about how temperature affects the internal structure and dynamics of surfactant aggregates can lead to a better understanding of their behavior in complex environments and processes. (13)C chemical shifts of the cationic surfactant tetradecytrimethylammonium bromide (TTAB) in micellar solution and when adsorbed on silica particles are recorded in the temperature range 8-78 °C, and give information on the conformation of the alkyl chain carbons. Adsorbed TTAB has conformational disorder similar to free TTAB at about 70 °C, with an increase in the rate of conformational changes occurring above 50 °C. Furthermore, no significant change in TTAB adsorption density was observed in the temperature range studied, and the results indicate a bilayer arrangement of the adsorbed surfactants. The number of gauche conformers increases linearly with temperature for the alkyl chain carbons in TTAB micelles. However, the total increase in gauche conformers is significantly smaller for micellar than for adsorbed TTAB within the temperature range studied. The fraction of micellized TTAB molecules in solution is found to increase with temperature.

7.
J Colloid Interface Sci ; 363(1): 362-70, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21840530

RESUMO

In this study, (1)H NMR is used to investigate properties of sodium dodecyl sulfate (SDS), tetradecyl trimethyl ammonium bromide (TTAB), and dodecyl trimethyl ammonium bromide (DTAB) adsorbed on kaolin by NMR T(1) and T(2) measurements of the water proton resonance. The results show that adsorbed surfactants form a barrier between sample water and the paramagnetic species present on the clay surface, thus significantly increasing the proton T(1) values of water. This effect is attributed to the amount of adsorbed surfactants and the arrangement of the surfactant aggregates. The total surface area covered by the cationic (DTAB and TTAB) and anionic (SDS) surfactants could be estimated from the water T(1) data and found to correspond to the fractions of negatively and positively charged surface area, respectively. For selected samples, the amount of paramagnetic species on the clay surface was reduced by treatment with hydrofluoric (HF) acid. For these samples, T(1) and T(2) measurements were taken in the temperature range 278-338 K, revealing detailed information on molecular mobility and nuclear exchange for the sample water that is related to surfactant behavior both on the surface and in the aqueous phase.


Assuntos
Caulim/química , Tensoativos/química , Água/química , Adsorção , Ácido Fluorídrico/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Tamanho da Partícula , Prótons , Propriedades de Superfície
8.
Langmuir ; 27(8): 4690-9, 2011 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-21413712

RESUMO

Detailed knowledge about the dynamics and structure of liquids in the vicinity of a solid surface is important in several fields of research. In this study a homogeneous model system of colloidal and nonporous silica particles with a narrow particle size distribution was used to examine such properties of adsorbed water and 1-heptanol. Doublet (1)H water resonances ("Pake doublets") indicate a preferred spatial orientation for the water molecules, as well as a lower molecular density in the surface-induced water structures compared to bulk water. These surface-induced structures are found to extend at least 8 nm from the silica surface. T(1) relaxation measurements at several temperatures indicate weaker H-bonding in the adsorbed water compared to bulk water. T(2) relaxation measurements at several temperatures reveal the presence of two water phases and give quantitative information on the mobility of water molecules and proton exchange processes. The presence of 1-heptanol changes the water characteristics, primarily in the water phase closer to the surface, where water molecules experience decreased translational and increased rotational freedom. In the absence of water, adsorbed 1-heptanol forms surface aggregates encompassing several molecular layers, where the first adsorbed layer shows severe restrictions in mobility and subsequent layers are more mobile.

9.
J Biol Inorg Chem ; 15(2): 213-23, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19768472

RESUMO

Cisplatin [cis-diamminedichloridoplatinum(II)] is used in chemotherapy where platinum-DNA adducts initiate tumor cell death. It is possible that side effects such as neurotoxicity and cellular cisplatin resistance can be due to interaction of cisplatin with lipids and the phospholipid bilayer. In this study, (13)C, (31)P, and (15)N solid-state NMR spectra of 1-palmitoyl-2-oleoyl phosphatidylserine (POPS) bilayers, POPS bilayers with 10 mol% cisplatin, and POPS bilayers with 30 mol% cisplatin were acquired. In addition, (15)N{(31)P} rotational echo double resonance spectra of POPS bilayers with 30 mol% cisplatin were acquired. The data demonstrate that the serine head group of phosphatidylserine binds to the aquated form of cisplatin and that cisplatin release of ammine takes place. It appears that the cisplatin release of ammine is followed by another cisplatin-POPS complex formation, possibly with cisplatin binding to one of the oxygen atoms of the POPS phosphate moiety.


Assuntos
Cisplatino/química , Bicamadas Lipídicas/química , Fosfatidilserinas/química , Cisplatino/síntese química , Bicamadas Lipídicas/síntese química , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Fosfatidilserinas/síntese química
10.
Acta Odontol Scand ; 67(1): 1-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18941950

RESUMO

OBJECTIVE: Local anesthetics are the most commonly used drugs in dentistry, with a wide range of effects, including antimicrobial activity. High antimicrobial effects have recently been reported on oral microbes from articaine hydrochloride, revealed by the minimum inhibitory concentration and minimal bactericidal concentration. Additionally, articaine has recently been used as an alkaline component in endodontic materials with a proposed antibacterial activity. However, the detailed mechanisms of action have not been discussed. MATERIAL AND METHODS: We determined the Langmuir surface pressure/molecular area isotherms of prokaryotic lipid monolayers, as well as the phospholipid phase transitions, by employing differential scanning calorimetry on unilamellar prokaryotic liposomes (bilayers). RESULTS: Articaine hydrochloride was found to interact with the prokaryotic membrane lipids in both monolayers and bilayers. An increase of the phospholipid molecular area of acidic glycerophospholipids as well as a decrease in phase transition temperature and enthalpy were found with increasing articaine hydrochloride concentration. The thermodynamic changes by adding articaine hydrochloride to prokaryotic membrane lipids are potentially related to the effects observed from antimicrobial peptides resulting from membrane insertion, aggregate composition, pore formation, and lysis. CONCLUSION: Interaction of articaine hydrochloride with prokaryotic membrane lipids is indicated. Hence, further research is necessary to gain insight into where these compounds exert their effects at the molecular level.


Assuntos
Antibacterianos/química , Carticaína/química , Membrana Celular/química , Lipídeos de Membrana/química , Fosfolipídeos/química , Anestesia Dentária , Anestésicos Locais/química , Varredura Diferencial de Calorimetria , Relação Dose-Resposta a Droga , Lipossomos , Transição de Fase , Células Procarióticas , Temperatura de Transição
11.
Eur J Pharm Sci ; 34(2-3): 140-8, 2008 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-18448315

RESUMO

Cisplatin (cis-diamminedichloroplatinum(II)) is used in chemotherapy and it is well established that cisplatin forms platinum-DNA adducts that initiate tumor cell death. Drawbacks are side effects such as neurotoxicity and cellular cisplatin resistance and it is possible that part of these effects are linked to cisplatin interaction with lipids and the phospholipid bilayer. 13C magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of total lipid extract from pig brain with and without cisplatin show that the phosphatidylserine (PS) carboxyl resonance disappears in presence of cisplatin and that a new resonance of similar intensity appears at 185.5 ppm. Thus, indicating cisplatin interaction with the PS head-group. Static and MAS 31P NMR spectra of lipid extract with and without cisplatin show that the phospholipids to a large extent reside in a bilayer environment in pure lipid extract, and that the presence of cisplatin promotes isotropic and/or hexagonal lipid phases.


Assuntos
Antineoplásicos/farmacologia , Química Encefálica , Cisplatino/farmacologia , Animais , Antineoplásicos/farmacocinética , Cisplatino/farmacocinética , Portadores de Fármacos , Bicamadas Lipídicas , Lipossomos , Espectroscopia de Ressonância Magnética , Fosfatidilserinas/química , Suínos
12.
Eur J Pharm Sci ; 33(4-5): 399-408, 2008 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-18343644

RESUMO

Articaine hydrochloride, 4-methyl-3-(2-[propylamino]propionamido)-2-thiophenecarboxylic acid, methyl ester hydrochloride, is a local anaesthetic commonly used in dentistry, and is classified as an amide local anaesthetic. Solid-state (13)C and (31)P NMR were used to investigate the uncharged articaine species (sample pH 10.0) when interacting with distearoylphosphatidylcholine (DSPC) model membranes. The DSPC phospholipid bilayer was studied at four different molar ratios of articaine, 10, 25, 40, and 55 mol%, respectively. The articaine concentration-dependent decrease in the DSPC bilayer gel-to-liquid-crystalline phase-transition temperature demonstrates substantial articaine interaction with this bilayer. A DSPC bilayer contains a large hydrophobic core and the (13)C and (31)P NMR spectra of the 40 mol% articaine-containing sample demonstrate a disturbance in the molecular packing of the polar bilayer region that extends into the hydrophobic region, evidenced by carbon 2 and 3 of the stearoyl acyl chains. Observed (31)P and (13)C NMR spectral changes when articaine is increased from 40 to 55 mol%, suggest formation of articaine aggregates and decrease in DSPC bilayer perturbation at the latter articaine level.


Assuntos
Anestésicos Locais/química , Carticaína/química , Bicamadas Lipídicas/química , Fosfatidilcolinas/química , Isótopos de Carbono , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Transição de Fase , Isótopos de Fósforo
13.
Biophys Chem ; 134(1-2): 47-55, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18241977

RESUMO

Phospholipid bilayer interaction of olanzapine (OLZ), a thienobenzodiazepine derivative and an antipsychotic agent, has been studied with (13)C and (31)P solid-state NMR. A dipalmitoyl phosphatidylcholine (60%)/1-palmitoyl-2-oleoyl phosphatidylserine (40%) bilayer (DPPC(60%)/POPS(40%)) with 50 wt.% H(2)O, with and without 10 mol% OLZ have been investigated. The results reveal that both the serine and the choline head groups are affected by OLZ interaction with the bilayer. The OLZ interaction with the serine and the choline head groups appears to be caused by electrostatic attraction to the serine head group carboxyl and repulsion of the choline head group positively charged nitrogen. (31)P MAS NMR experiments show the appearance of two new (31)P resonances both for the PS and the PC phosphorous in the presence of OLZ. Static (31)P NMR spectra demonstrate a decrease in chemical shift anisotropy (CSA) of the OLZ containing bilayer when in the liquid-crystalline phase and an increase in CSA when in the gel state.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Benzodiazepinas/química , Bicamadas Lipídicas/química , Fosfatidilserinas/química , Isótopos de Carbono/química , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Olanzapina , Transição de Fase , Isótopos de Fósforo/química , Temperatura
15.
Chemistry ; 13(11): 3169-76, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17203494

RESUMO

A series of functionalized mesoporous silicas with cagelike pore topology has been synthesized and screened for size-selective catalytic transformations. The aluminum-catalyzed Meerwein-Ponndorf-Verley (MPV) reduction of differently sized aromatic aldehydes (benzaldehyde and 1-pyrenecarbox-aldehyde) has been investigated as a test reaction. The catalysts were synthesized in a two-step grafting sequence comprising pore-size engineering of mesoporous silicas (SBA-1, SBA-2, SBA-16) with long-chain alkyl dimethylaminosilanes and surface organoaluminum chemistry with triethylaluminum [{Al(CH(2)CH(3))3}2]. Size-selective reaction behavior was found for small pore SBA-1 materials, and the selectivity could be efficiently tuned by selecting a silylating reagent of appropriate size. The results are compared with the catalytic performance of a large-pore periodic mesoporous organosilica PMO[SBA-1] and the nonporous high-surface-area silicas Aerosil 300/380.

16.
Biophys Chem ; 120(3): 178-87, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-16356624

RESUMO

The polyunsaturated fatty acid docosahexaenoic acid (DHA, 22:6, n-3) is found at a level of about 50% in the phospholipids of neuronal tissue membranes and appears to be crucial to human health. Dipalmitoyl phosphatidylcholine (DPPC, 16:0/16:0 PC) and the DHA containing 1-stearoyl-2-docosahexenoyl phosphatidylserine (SDPS) were used to make DPPC (60%)/SDPS (40%) bilayers with and without 10 mol% chlorpromazine (CPZ), a cationic, amphiphilic phenothiazine. Resonances that are present in 13C NMR spectrum of the DPPC (60%)/SDPS (40%) sample and that disappear in presence of 10% CPZ most probably are due to the special interface environment, e.g. the hydrophobic mismatch, at the interface of DPPC and SDPS microdomains in the DPPC/SDPS bilayer. In itself the appearance of resonances at novel chemical shift values is a clear demonstration of a unique chemical environment in the DPPC (60%)/SDPS (40%) bilayer. The findings of the study presented here suggest CPZ bound to the phosphate of SDPS will slow down and partially inhibit such a DHA acyl chain movement in the DPPC/SDPS bilayer. This would affect the area occupied by a SDPS molecule (in the bilayer) and probably the thickness of the bilayer where SDPS molecules reside as well. It is quite likely that such CPZ caused changes can affect the function of proteins embedded in the bilayer.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Clorpromazina/química , Ácidos Docosa-Hexaenoicos/química , Bicamadas Lipídicas/química , Microdomínios da Membrana/química , Fosfatidilserinas/química , Isótopos de Carbono , Espectroscopia de Ressonância Magnética , Estrutura Molecular
17.
Biophys Chem ; 117(2): 101-9, 2005 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-15921844

RESUMO

The polyunsaturated fatty acid docosahexaenoic acid (DHA, c22:6, n-3) is found at a level of about 50% in the phospholipids of neuronal tissue membranes and appears to be crucial to human health. Dipalmitoyl phosphatidylcholine (DPPC, 16:0/16:0 PC), 1-palmitoyl-2-oleoyl phosphatidylserine (POPS) and the DHA containing 1-stearaoyl-2-docosahexenoyl phosphatidylserine (SDPS) were used to make DPPC (60%)/POPS (29%)/SDPS (11%) bilayers with and without 10 mol% chlorpromazine (CPZ), a cationic, amphiphilic phenothiazine. The T1 relaxation measurements make it clear that the saturated acyl chains carbons (palmitic, stearic and most of the oleic chain) and the choline head group are not affected by CPZ addition. The observed increased signal intensity and T1-values of DHA indicate reduced mobility of C4 and C5 due to CPZ binding. 31P NMR spectra confirm that CPZ binding to the phosphatidylserines in the bilayer enhances phospholipid head group mobility.


Assuntos
Clorpromazina/química , Ácidos Docosa-Hexaenoicos/química , Espectroscopia de Ressonância Magnética/métodos , Fosfatidilserinas/química , Isótopos de Carbono , Cristalografia por Raios X , Bicamadas Lipídicas/química , Modelos Moleculares , Estrutura Molecular , Isótopos de Fósforo
18.
Biochim Biophys Acta ; 1682(1-3): 28-37, 2004 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15158753

RESUMO

Chlorpromazine (CPZ), a cationic, amphiphilic phenothiazine derivative is widely used as an antipsychotic drug because it antagonizes dopaminergic receptors. (13)C and (31)P solid-state NMR techniques were employed on phospholipid bilayers with and without CPZ. Phosphatidylserine from pig brain (PBPS), 1-palmitoyl-2-oleoyl phosphatidylserine (POPS), synthetic 1,2-dipalmitoyl phosphatidylcholine (DPPC) and chlorpromazineHCl were used to make phospholipid bilayers containing two types of phospholipids: DPPC (60%)/PBPS (40%) as well as POPS and PBPS bilayers without and with 10% CPZ. CPZ is found to prefer binding to the phosphate of phosphatidylserine, but also binding to the carboxyl of the serine head group in the DPPC/PBPS/CPZ bilayer is present. (31)P-NMR spectra indicate an effect of acyl chain unsaturation on the anisotropic motion of the charged serine head group. This implies that the serine head group anisotropic motion is restricted by intermolecular rather than intramolecular effects. The degree of phospholipid acyl chain unsaturation determines part of the CPZ bilayer interaction. The PBPS bilayer has the 22:6 acyl chain at 34 mol% and the C(4)?C(5) group of this acyl appears to be a determinant for CPZ bilayer interdigitation.


Assuntos
Clorpromazina/metabolismo , Fosfatidilserinas/metabolismo , Isótopos de Carbono , Clorpromazina/química , Lipossomos/química , Lipossomos/metabolismo , Espectroscopia de Ressonância Magnética , Fosfatidilserinas/química , Isótopos de Fósforo , Temperatura
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