1
|
Scattering Techniques and Ganglioside Aggregates: Laser Light, Neutron, and X-Ray Scattering. Methods Mol Biol 2019. [PMID: 29926404 DOI: 10.1007/978-1-4939-8552-4_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Scattering techniques are applied to studying the structural features of ganglioside aggregates in solution. Here it is described how different probing radiations allow to access different structural and dynamical parameters on different lengthscales. Besides a brief but comprehensive description of the scattering measurements, several practical suggestions are given concerning the experiments and the data analysis.
Collapse
|
2
|
Rondelli V, Brocca P, Tranquilli N, Fragneto G, Del Favero E, Cantù L. Building a biomimetic membrane for neutron reflectivity investigation: Complexity, asymmetry and contrast. Biophys Chem 2017; 229:135-141. [PMID: 28499578 DOI: 10.1016/j.bpc.2017.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 11/25/2022]
Abstract
The preparation and investigation of model membranes is deserving growing interest both for the physics of complex systems, and for biology. The need of simplified models should preserve mimicking the qualifying characteristics of biological membranes, and keep non-invasive and detailed description. As a main feature, biological membranes are non-homogeneous in the disposition of components, both in the lateral and in the transverse direction. We prepared asymmetric supported membranes containing GM1 ganglioside in biomimetic proportion according to different protocols. Then, we studied their internal structure by neutron reflectometry, providing few-Angstrom sensitivity in the cross direction meanwhile avoiding radiation damage. This technique can also be profitably applied to study interactions at the membrane surface. The best protocol has proven to be the Langmuir-Blodgett/Langmuir-Schaefer depositions. Notably, also the simpler and most accessible protocol of vesicle fusion was found to be suitable for straightforward and good quality deposition of compositionally asymmetric membranes.
Collapse
Affiliation(s)
- Valeria Rondelli
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy.
| | - Paola Brocca
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
| | - Nicola Tranquilli
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
| | - Giovanna Fragneto
- Institut Laue-Langevin, 71 Avenue des Martyrs, BP 156, 38000 Grenoble Cedex, France
| | - Elena Del Favero
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
| | - Laura Cantù
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
| |
Collapse
|
3
|
Gubaidullin AT, Litvinov IA, Samigullina AI, Zueva OS, Rukhlov VS, Idiyatullin BZ, Zuev YF. Structure and dynamics of concentrated micellar solutions of sodium dodecyl sulfate. Russ Chem Bull 2016. [DOI: 10.1007/s11172-016-1278-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
4
|
Del Favero E, Brocca P, Rondelli V, Motta S, Raudino A, Cantu' L. Optimizing the crowding strategy: sugar-based ionic micelles in the dilute-to-condensed regime. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9157-9164. [PMID: 25035176 DOI: 10.1021/la501963y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the present study, we explore the effect of concentration on micelles made by different gangliosides, which are ionic biological glycolipids bearing multisugar headgroups with huge steric hindrance. Moreover, strong preferential interactions exist among like-conformer headgroups that can keep the ganglioside micelles in a trapped configuration. We extend the well-known ionic-amphiphiles paradigm, where local condensation and micelle crowding are matched by forming larger aggregates at increasing concentration. In fact, we force the balance between interparticle and intraparticle interactions while allowing for like conformers to modulate rebalancing. In the vast experimental framework, obtained by Small Angle X-ray scattering (SAXS) experiments, a theoretical model, accounting for a collective conformational transition of the bulky headgroups, is developed and successfully tested. It allows us to shed some light on the nature and coupling of the intermolecular forces involved in the interactions among glycolipid micelles. Energy minimization leads to complex behavior of the aggregation number on increasing concentration, fully consistent with the experimental landscape. From a biological perspective, this result could be reflected in the properties of ganglioside-enriched rafts on cell membranes, with a nonlinear structural response to approaching bodies such as charged proteins.
Collapse
Affiliation(s)
- Elena Del Favero
- Department of Medical Biotechnologies and Traslational Medicine, University of Milano, LITA , Via F.lli Cervi 93, 20090 Segrate, Milano, Italy
| | | | | | | | | | | |
Collapse
|
5
|
Cantu' L, Del Favero E, Brocca P, Corti M. Multilevel structuring of ganglioside-containing aggregates: from simple micelles to complex biomimetic membranes. Adv Colloid Interface Sci 2014; 205:177-86. [PMID: 24188828 DOI: 10.1016/j.cis.2013.10.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/11/2013] [Accepted: 10/13/2013] [Indexed: 10/26/2022]
Abstract
We revisit the structural investigation we performed over the years on gangliosides, biological amphiphiles typically found in the cell membranes of the nervous system of mammalians. Their molecular features, a large and charged saccharidic headgroup connected to a sticky and extended ceramide double tail, strongly dictate their aggregation properties and place ganglioside aggregates at the borderline between the curved world and the flatland. All along we found that unexpected interesting behaviours were induced by the hierarchical propagation of such extreme monomer properties, from the aggregate scale to the mesoscopic phases. In fact, even small changes in the monomer geometry or hindrance result in dramatic aggregate reshaping, due to collective amplification. Surface packing optimization requires preferential mutual orientation of headgroups, giving rise to trapped solid-disordered configurations. The interplay between interparticle and intraparticle interactions gives rise to unexpected behaviours and counterintuitive phase's landscape. In situ modification of monomer properties, operated by enzymatic digestion of aggregated ganglioside headgroups, either causes collective rearrangement or is overwhelmed by collective trapping, depending on their surface density. This aspect is interesting as gangliosides are not evenly distributed in cell membranes, but only in the outer leaflet, where they p]articipate in rafts, functional microdomains enriched in special lipids including cholesterol. We recently found that ganglioside GM1 forces a preferential distribution of cholesterol, constituting a collective structural pair across the membrane. In summary, ganglioside assemblies, through cooperativity, reach a structural complexity comparable or even bigger and more adaptive than that of a protein.
Collapse
|
6
|
Gangliosides and the multiscale modulation of membrane structure. Chem Phys Lipids 2011; 164:796-810. [DOI: 10.1016/j.chemphyslip.2011.09.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 09/12/2011] [Accepted: 09/13/2011] [Indexed: 02/07/2023]
|
7
|
Šachl R, Rosenbaum E, Sellstedt M, Almqvist F, Johansson LBÅ. Locations and reorientations of multi-ring-fused 2-pyridones in ganglioside G(M1) micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1662-1667. [PMID: 21210677 DOI: 10.1021/la104051z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Fluorescent multi-ring-fused 2-pyridones, with chemical resemblance to other biologically active 2-pyridone systems, were solubilized in spherical micelles formed by the ganglioside G(M1) and studied with respect to their spatial localization and rotational mobility. For this, electronic energy transfer between the multi-ring-fused 2-pyridone (donor) and BODIPY-FL-labeled G(M1) was determined, as well as their fluorescence depolarization. From the obtained efficiency of energy transfer to the acceptor group (BODIPY-FL), either localized in the polar or in the nonpolar part of the ganglioside, it has been possible to estimate the most likely localization of the multi-ring-fused 2-pyridones. The center of mass of the studied multi-ring-fused 2-pyridones are located at approximately 33 Å from the micellar center of mass, which corresponds to the internal hydrophobic-hydrophilic interfacial region. At this location, the reorienting rates of the multi-ring-fused 2-pyridones are surprisingly slow with typical correlation times of 35-55 ns. No evidence was found for the formation of ground and excited state dimers, even when two monomers were forced to be near each other via a short covalent linker.
Collapse
Affiliation(s)
- Radek Šachl
- Department of Chemistry, Umeå University, SE-90 187 Umeå, Sweden
| | | | | | | | | |
Collapse
|
8
|
Del Favero E, Brocca P, Motta S, Rondelli V, Sonnino S, Cantu′ L. Nanoscale structural response of ganglioside-containing aggregates to the interaction with sialidase. J Neurochem 2011; 116:833-9. [DOI: 10.1111/j.1471-4159.2010.07031.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
9
|
Gavella M, Kveder M, Lipovac V. Modulation of ROS production in human leukocytes by ganglioside micelles. Braz J Med Biol Res 2010; 43:942-9. [DOI: 10.1590/s0100-879x2010007500092] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Accepted: 09/02/2010] [Indexed: 11/21/2022] Open
Affiliation(s)
- M. Gavella
- Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Croatia
| | | | - V. Lipovac
- Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Croatia
| |
Collapse
|
10
|
Gavella M, Kveder M, Lipovac V, Jurasin D, Filipovi-Vincekovic N. Antioxidant properties of ganglioside micelles. Free Radic Res 2009; 41:1143-50. [PMID: 17886036 DOI: 10.1080/10715760701618245] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Antioxidant activity of gangliosides GM1 and GT1b in the Fenton type of reaction was investigated by EPR spectroscopy using DMPO as a spin trap. Hydroxyl radical spin adduct signal intensity was significantly reduced in the presence of gangliosides at their micellar concentrations. Mean micellar hydrodynamic diameter was not changed, whereas significant changes in negative Zeta potential values were observed as evidenced by Zetasizer Nano ZS. This study showed that the primary mode of ganglioside action was not due to direct scavenging of OH., but rather to the inhibition of hydroxyl radical formation. This phenomenon is related to the ability of ganglioside micelles to bind oppositely charged ferrous ions, thus reducing their concentration and consequently inhibiting OH. formation.
Collapse
Affiliation(s)
- Mirjana Gavella
- Laboratory of Cell Biochemistry, Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Zagreb, Croatia.
| | | | | | | | | |
Collapse
|
11
|
Sachl R, Mikhalyov I, Hof M, Johansson LBA. A comparative study on ganglioside micelles using electronic energy transfer, fluorescence correlation spectroscopy and light scattering techniques. Phys Chem Chem Phys 2009; 11:4335-43. [PMID: 19458836 DOI: 10.1039/b821658d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ganglioside (G(M1)) micelles have been studied by means of three different techniques: fluorescence correlation spectroscopy (FCS), electronic energy transfer, as monitored by time-resolved fluorescence spectroscopy, as well as static and dynamic light scattering. The aggregation numbers obtained, 168 +/- 4, remain constant over a wide range of G(M1) concentrations (0.764-156 muM), are very consistent when using different donor-acceptor energy transfer pairs and have served as reference values in tests of the FCS method. It is recommended to calibrate the focal volume by using known dye concentrations. For this the rhodamine dye, 5-TAMRA, turns out to be most suitable. It is also shown that FCS provides correct values of the aggregation numbers, provided that the focal volume is calibrated by using updated values of the diffusion constant of Rhodamine 6G. These results also support recent methodological advances in FCS.
Collapse
Affiliation(s)
- Radek Sachl
- Department of Chemistry, Biophysical Chemistry, Umeå University, S-901 87, Umeå, Sweden
| | | | | | | |
Collapse
|
12
|
Cantu' L, Corti M, Brocca P, Del Favero E. Structural aspects of ganglioside-containing membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1788:202-8. [PMID: 19063860 DOI: 10.1016/j.bbamem.2008.11.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 11/04/2008] [Accepted: 11/04/2008] [Indexed: 11/15/2022]
Abstract
The demand for understanding the physical role of gangliosides in membranes is pressing, due to the high number of diverse and crucial biological functions in which they are involved, needing a unifying thread. To this purpose, model systems including gangliosides have been subject of extensive structural studies. Although showing different levels of complication, all models share the need for simplicity, in order to allow for physico-chemical clarity, so they keep far from the extreme complexity of the true biological systems. Nonetheless, as widely agreed, they provide a basic hint on the structural contribution specific molecules can pay to the complex aggregate. This topic we address in the present review. Gangliosides are likely to play their physical role through metamorphism, cooperativity and demixing, that is, they tend to segregate and identify regions where they can dictate and modulate the geometry and the topology of the structure, and its mechanical properties. Strong three-dimensional organisation and cooperativity are exploited to scale up the local arrangement hierarchically from the nano- to the mesoscale, influencing the overall morphology of the structure.
Collapse
Affiliation(s)
- Laura Cantu'
- Department of Chemistry, Biochemistry and Biotechnologies for Medicine, University of Milano, Segrate (Mi), Italy.
| | | | | | | |
Collapse
|
13
|
Baldelli Bombelli F, Berti D, Milani S, Lagi M, Barbaro P, Karlsson G, Brandt A, Baglioni P. Collective headgroup conformational transition in twisted micellar superstructures. SOFT MATTER 2008; 4:1102-1113. [PMID: 32907145 DOI: 10.1039/b800210j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Predictions on amphiphilic self-assemblies traditionally rely on considerations on molecular shape and charge of the surfactant. In the case of functional surfactants a more sophisticated toolbox becomes necessary to design amphiphiles encoding chemical functionalities that provide additional responsive properties to their self-assemblies. Here we report on a comprehensive and combined structural-spectroscopic characterization of 1,2-dilauroyl-phosphatidyl-adenosine (DLPA) micelles in phosphate buffer. The temperature dependence, more precisely the thermal history of the sample, is explicitly taken into account. The experimental data, supplemented with MD simulations, indicate the presence of two possible states at room temperature, characterized by distinctly different structural properties that depend on the thermal history of the sample. The twisted superstructures, produced by aging DLPA micelles through intermicellar assembly of locally cylindrical aggregates at room temperature, collapse upon warming at 35 °C, yielding aligned filaments and/or wormlike structures. The initial superstructures cannot be recovered by thermal inversion. The reason for this behaviour is that the thermal activation causes a redistribution of syn-anti conformations of adenosine headgroups, as indicated by spectroscopic results (NMR, CD, FTIR), which is then collectively frozen thanks to molecular constraints present in the aggregate.
Collapse
Affiliation(s)
| | - Debora Berti
- Department of Chemistry and CSGI, University of Florence, Sesto Fiorentino, Florence, Italy.
| | - Silvia Milani
- Department of Chemistry and CSGI, University of Florence, Sesto Fiorentino, Florence, Italy.
| | - Marco Lagi
- Department of Chemistry and CSGI, University of Florence, Sesto Fiorentino, Florence, Italy.
| | | | - Göran Karlsson
- Department of Physical and Analytical Chemistry, Uppsala University, Sweden
| | | | - Piero Baglioni
- Department of Chemistry and CSGI, University of Florence, Sesto Fiorentino, Florence, Italy.
| |
Collapse
|