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249 results on '"Rapaport, Hanna"'

10. Intracellular spatially-targeted chemical chaperones increase native state stability of mutant SOD1 barrel

Author

Ribeiro, Sara S., primary, Gnutt, David, additional, Azoulay-Ginsburg, Salome, additional, Fetahaj, Zamira, additional, Spurlock, Ella, additional, Lindner, Felix, additional, Kuz, Damon, additional, Cohen-Erez, Yfat, additional, Rapaport, Hanna, additional, Israelson, Adrian, additional, Gruzman, Arie-lev, additional, and Ebbinghaus, Simon, additional

Published
2023
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22. Two-dimensional ordered beta-sheet lipopeptide monolayers

Author

Cavalli, Silvia, Handgraaf, Jan-Willem, Tellers, Emily E., Popescu, Daniela C., Overhand, Mark, Kjaer, Kristian, Valser, Vladimir, Sommerdijk, Nico A.J.M., Rapaport, Hanna, and Kros, Alexander

Subjects
Monomolecular films -- Structure, Monomolecular films -- Chemical properties, Peptides -- Chemical properties, Peptides -- Structure, Hydrophobic effect -- Analysis, Fourier transform infrared spectroscopy -- Usage, Chemistry
Abstract

A series of amphiphilic lipopeptides (ALPs), consisting of an alternating hydrophilic and hydrophobic amino acid residue sequence coupled to a phospholipids tail, was designed to form supramolecular assemblies composed of beta-sheet monolayers decorated by lipid tails at the air-water interface. In situ grazing-incidence X-ray diffraction (GIXD) revealed that lipopeptides six to eight amino acids in length form a new type of 2-dimensional (2D) self-organized monolayers that exhibit beta-sheet ribbons segregated by lipid tails.

Published
2006

24. Design and characterization of crystalline thin film architectures at the air-liquid interface: simplicity to complexity

Author

Kuzmenko, Ivan, Rapaport, Hanna, Kjaer, Kristian, Als-Nielsen, Jens, Weissbuch, Isabelle, Lahav, Meir, and Leiserowitz, Leslie

Subjects
Biochemistry -- Research, Thin films -- Physiological aspects, Solution (Chemistry) -- Physiological aspects, Molecules -- Research, Chemistry
Abstract

Research has been conducted on the ordered films at the air-solution interface. The crystallite multilayers composed of water-insoluble molecules and multilayers generated by the reaction between the water-insoluble species with the subphase solutes have been investigated and described.

Published
2001

27. Crystalline cyclic peptide nanotubes at interfaces

Author

Rapaport, Hanna, Kim, Hui Sun, Kjaer, Kristian, Howes, Paul B., Cohen, Sidney, Als-Nielsen, Jens, Ghadiri, M. Reza, Leiserowitz, Leslie, and Lahav, Meir

Subjects
Peptides -- Research, Phospholipids -- Research, Biological transport -- Research, Molecular structure -- Research, Chemistry
Abstract

A study was conducted to clearly characterize some of the structural factors governing the supramolecular organization of the three cyclic peptides belonging to the class of self-assembling peptide nanotubes. The experiment was performed by using grazing incidence X-ray diffraction of Langmuir films of the peptides. Grazing incidence X-ray diffraction and scanning force microscopy were also used to observe the effect of the phospholipid L-alpha-phosphatidic acid dipalmitoyl on the aggregation behavior of two of the peptides.

Published
1999

28. Monitoring the nucleation of crystalline films of cholesterol on water and in the presence of phospholipid

Author

Lafont, Sylvaine, Rapaport, Hanna, Somjen, Giora J., Renault, Anne, Howes, Paul B., Kjaer, Kristian, Als-Nielsen, Jens, Leiserowitz, Leslie, and Lahav, Meir

Subjects
Cholesterol -- Analysis, Phospholipids -- Analysis, Nucleation -- Analysis, Crystallization -- Analysis, Chemicals, plastics and rubber industries
Abstract

A study using surface-sensitive techniques determined the nucleation of two-dimensional crystals of pure cholesterol and its mixtures with dipalmitoylphosphatidylcholine at the air-water interface. Based on grazing-incidence X-ray diffraction measurements, there is a transition from a monolayer to a highly crystalline rectangular phase, with thickness of two layers. Moreover, atomic force microscopy revealed that films transferred onto solid support possesses elongated and faceted crystallites with thickness of approximately 10 layers. Lastly, the phospholipid additive lowered the crystallinity of the cholesterol in two mixtures.

Published
1998

29. Structural characterization of valinomycin and nonactin at the air-solution interface by grazing incidence X-ray diffraction

Author

Rapaport, Hanna, Kuzmenko, Ivan, Kjaer, Kristian, Howes, Paul, Bouwman, Wim, Als-Nielsen, Jens, Leiserowitz, Leslie, and Lahav, Meir

Subjects
Ionophores -- Research, Chemistry
Abstract

Grazing incidence X-ray diffraction can be used to reveal structural features of two-dimensional films of the ionophores valinomycin (VM) and nonactin (NA) when complexed with a number of different cations at air-aqueous solution interfaces. Lateral pressure, the presence of a matrix compound and the type of counterions present in solution can be used to control the 2D crystallization of the complexed ionophores and their tendency to stack. The ordered films at the air-solution interface show basically the same packing as the 3D counterpart.

Published
1997

32. From nucleation to engineering of crystalline architectures at air-liquid interfaces

Author

Rapaport, Hanna, Kuzmenko, Ivan, Berfeld, Mary, Kjaer, Kristian, Als-Nielsen, Jens, Popovitz-Biro, Ronit, Weissbuch, Isabelle, Lahav, Meir, and Leiserowitz, Leslie

Subjects
Chemical research -- Analysis, Chemistry, Physical and theoretical -- Research, Chemicals, plastics and rubber industries
Abstract

Issues concerning the investigation of three regimes of molecular organization at the air-solution interface by the use of grazing incidence X-ray diffraction are discussed.

Published
2000

39. Elasticity of crystalline beta-sheet monolayers

Author

Isenberg, Hila, Kjaer, Kristian, and Rapaport, Hanna

Subjects
Monomolecular films -- Properties, Elasticity -- Measurement, X-rays -- Diffraction, X-rays -- Usage, Chemistry
Abstract

Experimental evidence of beta-sheet elastic-like behavior that was detected by grazing incidence X-ray diffraction measurements, performed along surface X-ray diffraction measurements is presented. Results show the presence of two characteristic compressibility regions for crystalline [P.sub.Glu]-5 assemblies below and above pi approximately 3 mN/m respectively.

Published
2006

41. Membrane Determinants Affect Fibrillation Processes of β-Sheet Charged Peptides

Author

Arad, Elad, Malishev, Ravit, Rapaport, Hanna, and Jelinek, Raz

Abstract

Assembly of fibrillar peptide structures is dependent both upon their intrinsic propensities toward β-structure formation, as well as on structural modulation by external molecular factors. β-sheet structures may either be designed to form useful assemblies or be the undesired consequence of protein denaturation to toxic amyloid structures in several neurodegenerative diseases. Membrane bilayers have been implicated as primary initiators and modulators of amyloid fibrillation and the reasons for this effect are yet to be elucidated. Here, we employed a set of three charged peptides having the tendency to form β-sheet fibrils, to investigate the effect of zwitterionic and negatively charged bilayer vesicles on their assembly structures. Microscopic and spectroscopic experiments revealed intimate relationship between peptide/membrane charges and fibrillation properties. Electrostatic attraction was apparent between oppositely charged peptides and vesicles; however, such interactions did not appear to significantly modulate fibril morphologies of either the net anionic peptide or the cationic one. Yet, a dramatic structural effect was observed when the nominal zwitterionic peptide underwent fibrillation in the presence of negatively charged vesicles. Assemblies of this peptide display a net positive charge, which facilitated the counterionic interactions with the vesicles. Furthermore, these interactions templated a unique twisted fiber morphology demonstrating the dramatic effect membrane-mediated interactions exert on fibril morphologies.

Published
2024
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42. Decoupling Charge and Side Chain Effects in Hierarchical Organization of Cationic PFX Peptide and Alginate

Author

Yosefi, Gal, Kass, Itamar, Rapaport, Hanna, and Bitton, Ronit

Abstract

We have successfully created self-assembled membranes by combining positively charged (Pro-X-(Phe-X)5-Pro) PFX peptides with negatively charged alginate. These PFX/alginate membranes were formed by three different peptides that contain either X = Arginine (R), Histidine (H), or Ornithine (O) as their charged amino acid. The assemblies were compared to membranes that were previously reported by us composed of X = lysine (K). This study enabled us to elucidate the impact of amino acids’ specific interactions on membrane formation. SEM, SAXS, and cryo-TEM measurements show that although K, R, H, and O may have a similar net charge, the specific traits of the charged amino acid is an essential factor in determining the hierarchical structure of alginate/PFX self-assembled membranes.

Published
2024
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43. Antitumor Effect of Lonidamine-Polypeptide-Peptide Nanoparticles in Breast Cancer Models

Author

Cohen-Erez, Ifat, Issacson, Carol, Lavi, Yael, Shaco-Levy, Ruthy, Milam, Jammi, Laster, Brenda, Gheber, Levi A., and Rapaport, Hanna

Abstract

Biomaterials folded into nanoparticles (NPs) can be utilized as targeted drug delivery systems for cancer therapy. NPs may provide a vehicle for the anticancer drug lonidamine (LND), which inhibits glycolysis but was suspended from use at the clinical trial stage because of its hepatotoxicity due to poor solubility and pharmacokinetic properties. The NPs prepared by coassembly of the anionic polypeptide poly gamma glutamic acid (γ-PGA) and a designed amphiphilic and positively charged peptide (designated as mPoP-NPs) delivered LND to the mitochondria in cell cultures. In this study, we demonstrate that LND-mPoP-NP effective drug concentrations can be increased to reach therapeutically relevant concentrations. The self-assembled NP solution was subjected to snap-freezing and lyophilization and the resultant powder was redissolved in a tenth of the original volume. The NP size and their ability to target the proximity of the mitochondria of breast cancer cells were both maintained in this new formulation, C-LND-mPoP-NPs. Furthermore, these NPs exhibited 40% better cytotoxicity, relative to the nonlyophilized LND-mPoP-NPs and led to tumor growth inhibition with no adverse side effects upon intravenous administration in a xenograft breast cancer murine model.

Published
2024
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50. Assembly of triple-standard beta-sheet peptides at interfaces

Author

Rapaport, Hanna, Moller, Gunter, Knobler, Charles M., Jensen, Torben R., Kjaer, Kristian, Tirrell, David A., and Leiserowitz, Leslie

Subjects
Molecular dynamics -- Research, Peptides -- Chemical properties, Chemistry
Abstract

Generation of an ordered 2D molecular assembly composed of triple-standard amphipilic peptides arrayed at the air-water interface is described. The study demonstrates simple design principles for the preparation of ordered macromolecular assemblies at the air-water interface.

Published
2002

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