Éva Kiss - Academia.edu (original) (raw)

Papers by Éva Kiss

Acta pharmaceutica Hungarica, Nov 15, 2021

Express Polymer Letters, 2022

Electrophoresis, 1996

to calculate the capacity factor in micellar electrokinetic chromatography (MEKC), where t,, to, ... more to calculate the capacity factor in micellar electrokinetic chromatography (MEKC), where t,, to, and t,, are the migration time of the analyte, the flow marker, and the micelles, respectively. The K and K' values that were obtained from simulated data as well as from MEKC analysis of different peptides (in 100 mM sodium dodecyl sulfate/O.l N sodium borate buffer at pH 11.0) were calculated and compared. The K' value is equal to zero for an analyte remaining in the aqueous phase whereas it is equal to one for an analyte always staying in the micellar phase. By applying K' a finite capacity factor can be obtained for an analyte, indicating its partition between the two moving phases (aqueous and micellar) even in those cases when t, equals tmc. The slope of the curve K' as a function of t, is constant through the whole migration window and therefore peak compression does not occur when applying K' to calculate the capacity factor. A given difference in K' corresponds the same difference in migration times and this value does not depend on the position within the migration window. Since K' is a normalized parameter it is easy to evaluate the significance of a given difference in capacity factor or to estimate the relative position of an analyte with a given capacity factor in the migration window by applying K'. Therefore, K' seems to be an adequate parameter to calculate the capacity factor in MEKC and, similar to K , it also refers to the hydrophobicity of the analyte.

A pályázat végrehajtása során elért eredményeket az alábbi csoportosítás szerint tárgyaljuk: 1. K... more A pályázat végrehajtása során elért eredményeket az alábbi csoportosítás szerint tárgyaljuk: 1. Különböző elválasztás-technikai módszerek fejlesztése és karakterizálása 1.1-MEKC : elválasztást befolyásoló paraméterek vizsgálata 1.2-CE : elválasztást befolyásoló paraméterek vizsgálata 1.3-HPLC:hidrofóbitás vizsgálata IAM és RP-HPLC oszlopokon 2. Elválasztás-technikai módszerek alkalmazása különböző típusú molekulakönyvtárak jellemzésére: modell vegyületek hidrofóbitásának kísérleti és számítógépes úton történő meghatározása 2.1benzylidén cikloalkanon származékok 2.2-izokromanonok 3. Molekulakönyvtárak fizikia-kémiai és biológiai karakterizálása 3.1-peptidomimetikumok (tumor és neurogén gyulladásgátlók, retenciós időkhidrofóbicitás) 3.2-angiogenezisre ható peptidek (stabilitás vizsgálata HPLC-vel, kapszulázáshoz) 3.3-ionos folyadékok CORE Metadata, citation and similar papers at core.ac.uk

Collection of Czechoslovak Chemical Communications, Jul 1, 2022

Microbial biotechnology, Mar 19, 2021

We developed a cost sensitive isotope labelling procedure using a fed-batch fermentation method a... more We developed a cost sensitive isotope labelling procedure using a fed-batch fermentation method and tested its efficiency producing the 15 N-, 13 C-and 15 N/ 13 C-labelled variants of an amyloidogenic miniprotein (E5: EEEAVRLYIQWLKEGGPSSGRPPPS). E5 is a surface active protein, which forms amyloids in solution. Here, we confirm, using both PM-IRRAS and AFM measurements, that the air-water interface triggers structural rearrangement and promotes the amyloid formation of E5, and thus it is a suitable test protein to work out efficient isotope labelling schemes even for such difficult sequences. E. coli cells expressing the recombinant, ubiquitin-fused miniprotein were grown in minimal media containing either unlabelled nutrients, or 15 N-NH 4 Cl and/or 13 C-D-Glc. The consumption rates of NH 4 Cl and D-Glc were quantitatively monitored during fermentation and their ratio was established to be 1:5 (for NH 4 Cl: D-Glc). One-and twostep feeding schemes were custom-optimized to enhance isotope incorporation expressing five different E5 miniprotein variants. With the currently optimized protocols we could achieve a 1.5-to 5-fold increase of yields of several miniproteins coupled to a similar magnitude of cost reduction as compared to flask labelling protocols.

Macromolecules, Dec 1, 2006

The surface properties of three water-soluble and amphiphilic PEO-PPO-PEO triblock copolymers of ... more The surface properties of three water-soluble and amphiphilic PEO-PPO-PEO triblock copolymers of different composition (Pluronic 6100, 6400, and 6800) are investigated by tensiometry and sum-frequency vibrational spectroscopy. We compared the concentration dependence of the structure of surface layers prepared by three different methods: (i) adsorption from aqueous solution, (ii) dropwise spreading from an organic solution onto a surface of constant area, and (iii) compression of the spread film in a Langmuir trough. The surface density and conformation of the polymers were deduced from the vibrational band intensities of the methyl groups of the central hydrophobic PPO block and from the surface tension isotherms. A transition range related to a conformational change was observed by tensiometry for the adsorbed and the compressed Langmuir films of Pluronics with short PEO blocks, whereas the Pluronic with longest PEO blocks displays a gradual change of surface pressure without the sign of a phase transition. This difference reveals the effect of the relative lengths of the hydrophilic and hydrophobic blocks on the structural changes in the surface layers of block copolymers. A clear indication of the influence of the hydrophilic blocks on the structure of the whole molecule at the interface was also observed in the sum-frequency experiments. Above a given concentration the Pluronic with longest PEO chains exhibited lower sum-frequency intensities and methyl symmetric/asymmetric amplitude ratios than the other Pluronic compounds for all of the layers formed by the various methods. The differences in the surface properties of the dropwise spread layers and of the compressed Langmuir layers exposed the importance of the kinetic aspects of polymer monolayer formation. In the case of the spread films the possible large degree of nonequilibrium chain entanglements might hinder the accomplishment of preferred orientation and conformation of the polymer chains.

Journal of Medicinal Chemistry, 2021

Most therapeutic agents used for treating brain malignancies face hindered transport through the ... more Most therapeutic agents used for treating brain malignancies face hindered transport through the blood−brain barrier (BBB) and poor tissue penetration. To overcome these problems, we developed peptide conjugates of conventional and experimental anticancer agents. SynB3 cell-penetrating peptide derivatives were applied that can cross the BBB. Tuftsin derivatives were used to target the neuropilin-1 transport system for selectivity and better tumor penetration. Moreover, SynB3-tuftsin tandem compounds were synthesized to combine the beneficial properties of these peptides. Most of the conjugates showed high and selective efficacy against glioblastoma cells. SynB3 and tandem derivatives demonstrated superior cellular internalization. The penetration profile of the conjugates was determined on a lipid monolayer and Transwell co-culture system with noncontact HUVEC-U87 monolayers as simple ex vivo and in vitro BBB models. Importantly, in 3D spheroids, daunomycin-peptide conjugates possessed a better tumor penetration ability than daunomycin. These conjugates are promising tools for the delivery systems with tunable features.

International journal of molecular sciences, Jan 22, 2018

In rheumatoid arthritis (RA), anti-citrullinated protein/peptide antibodies (ACPAs) are responsib... more In rheumatoid arthritis (RA), anti-citrullinated protein/peptide antibodies (ACPAs) are responsible for disease onset and progression, however, our knowledge is limited on ligand binding affinities of autoantibodies with different citrulline-peptide specificity. Citrulline-peptide-specific ACPA IgGs were affinity purified and tested by ELISA. Binding affinities of ACPA IgGs and serum antibodies were compared by surface plasmon resonance (SPR) analysis. Bifunctional nanoparticles harboring a multi-epitope citrulline-peptide and a complement-activating peptide were used to induce selective depletion of ACPA-producing B cells. values of affinity-purified ACPA IgGs varied between 10 and 10 M and inversely correlated with disease activity. Based on their cross-reaction with citrulline-peptides, we designed a novel multi-epitope peptide, containing Cit-Gly and Ala-Cit motifs in two-two copies, separated with a short, neutral spacer. This peptide detected antibodies in RA sera with 66% sen...

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014

Biodegradable poly(lactic-co-glycolic acid)(PLGA 50:50) nanoparticles (NPs) were prepared and cha... more Biodegradable poly(lactic-co-glycolic acid)(PLGA 50:50) nanoparticles (NPs) were prepared and characterized in terms of size, composition, zeta potential and colloidal stability. Surface modification of PLGA NPs where primary amino groups were introduced to the Pluronic surface layer was developed. This method allows modulation of the charge character of the nanoparticle surface and provides functional groups for chemical reactions useful for targeting while retaining the aggregation stability of the system. The nanoparticles showed significant interaction with model membrane system (DPPC and DPPC+DPPG lipid layers) depending on the amount and type of Pluronic applied for stabilization of NPs. A new antitubercular drug candidate was encapsulated into the PLGA NPs. The cellular uptake and the intracellular efficacy against Mycobacterium tuberculosis (Mtb) of the drug and the drug loaded nanoparticulate systems were investigated. These formulations were successfully taken up by MonoMac6 human monocyte cells and highly enhanced the availability and efficacy of the drug against Mtb which was demonstrated in comparative in vitro experiments.

Macromolecules, 2006

Journal of Colloid and Interface Science, 2008

Interaction of bovine serum albumin (BSA) with poly(lactic acid) (PLA) layers mixed with poly(eth... more Interaction of bovine serum albumin (BSA) with poly(lactic acid) (PLA) layers mixed with poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers (Pluronic) at air/solution interfaces was studied by the Langmuir balance technique. Wettability of the mixed PLA-Pluronic system was characterized in the form of a transferred one-layer Langmuir-Blodgett film, and considerable hydrophilization was obtained for all of the Pluronics (6400, 6800, 10500, and 12700) applied here. The density of PEO chains in the monolayer and hence the coverage of PLA was controlled by the composition and the compression of the mixed monolayers. Tensiometric investigations revealed that a significant reduction of BSA adsorption/penetration was achieved by applying the Pluronic 6800 and 12700 with long PEO blocks for hydrophilization of PLA. Interaction of BSA with the modified PLA monolayer depended on the density and length of the PEO chains. The surface morphological characteristics of the films determined by atomic force microscopy were in good correlation with the results of BSA interaction. The average roughness of the polymer LB layer was high due to BSA penetration into the PLA film, while smooth surfaces with small roughness were obtained when the PLA layer was modified by Pluronic 6800.

ELECTROPHORESIS, 1996

In addition to the expression, k′ = (tm−to)/to (1–tm/tmc), we propose the expression k″ = (tm−to)... more In addition to the expression, k′ = (tm−to)/to (1–tm/tmc), we propose the expression k″ = (tm−to)/(tmc−to) to calculate the capacity factor in micellar electrokinetic chromatography (MEKC), where tm, to, and tmc are the migration time of the analyte, the flow marker, and the micelles, respectively. The k′ and k″ values that were obtained from simulated data as well as from MEKC analysis of different peptides (in 100 mM sodium dodecyl sulfate/0.1 N sodium borate buffer at pH 11.0) were calculated and compared. The k″ value is equal to zero for an analyte remaining in the aqueous phase whereas it is equal to one for an analyte always staying in the micellar phase. By applying k″ a finite capacity factor can be obtained for an analyte, indicating its partition between the two moving phases (aqueous and micellar) even in those cases when tm equals tmc. The slope of the curve k″ as a function of tm is constant through the whole migration window and therefore peak compression does not occ...

... HORVATI KATA (Eoetvoes Lorand Univ., Budapest, Hun) BOSZE SZILVIA (Res. Group Of Peptide Chem... more ... HORVATI KATA (Eoetvoes Lorand Univ., Budapest, Hun) BOSZE SZILVIA (Res. Group Of Peptide Chemistry, Hungarian Acad. Sci.) BOSZE SZILVIA (Eoetvoes Lorand Univ., Budapest, Hun) SZABO NORA (Koranyi National Inst. Tb And Pulmonology, Budapest, Hun) KISS EVA ...