Volume 7 (2002) pp 839-843 |
Title |
PLANAR, CYLINDRICAL AND SPHERICAL ELECTRICAL DOUBLE
LAYERS IN BIOLOGICAL SYSTEMS. THE EFFECT OF
COUNTERION SIZE |
Authors |
Klemen Bohinc1,Aleš Iglič1, Tomaž Slivnik1 and Veronika Kralj-Iglič 2 |
Abstract |
The effect of counterion size on the electrical properties of an
electrolyte solution in contact with charged planar, cylindrical and spherical
surfaces is considered. Electrostatic interaction is considered by means of the
mean electrostatic field, while the finite size of particles constituting the
electrolyte solution is considered via the excluded volume effect within the
lattice statistics. Different sizes of counterion are described by different values
of the lattice constant. It is shown that the excluded volume effect considerably
decreases the calculated number density of counterions near the charged surface.
This effect is more pronounced in cylindrical geometry than in spherical
geometry, and less pronounced than in planar geometry. |
Address and Contact Information |
1Faculty of Electrical Engineering, Tržaška 25, SI-1000 Ljubljana, Slovenia,
2Institute of Biophysics, Faculty of Medicine, Lipičeva 2, SI-1000 Ljubljana,
Slovenia |
|
Volume 7 (2002) pp 845-848 |
Title |
MOLECULAR MARKERS OF INBRED RADISH (Raphanus sativus var.
Radicola Pers.) LINES |
Authors |
Tatiana V. Matveeva*, Anna V. Simonova and Ludmila A. Lutova |
Abstract |
An approach which could be used for quick searches for RAPD
markers is described for groups of radish lines with certain morphological traits.
The lines are characterized by various morpho-physiological abnormalities,
including tumor formation (lines 12, 19, and 21) and non-terminal development
of the flower meristem as a variant of tumor growth (line 6). We found four
markers which differentiate tumor radish lines 12, 19, and 21 from the others,
and two which differentiate line 6. |
Address and Contact Information |
St. Petersburg State University, 199034 St. Petersburg, Russia
* Corresponding author, E-mail: radishlet@yahoo.com |
|
Volume 7 (2002) pp 849-858 |
Title |
ALTERNATIVE METHODS OF PLANT TRANSFORMATION -
A SHORT REVIEW |
Authors |
Monika Rakoczy-Trojanowska* |
Abstract |
Several methods of transformation are currently available for
delivering exogenous DNA to plant cells. Agrobacterium-mediated
transformation, microprojectile bombardment and direct protoplast
transformation are routinely used today. However, each of them has certain
disadvantages, which led to research into the development of novel alternative
systems such as infiltration, electroporation of cells and tissues, electrophoresis
of embryos, microinjection, pollen-tube pathway, silicon carbide- and liposomemediated
transformation. The low efficiency of transformation is considered to
be the main reason for the limited popularity of the alternative transformation
methods, other than infiltration and silicon carbide-mediated transformation,
which seem to be the most promising ones for practice. |
Address and Contact Information |
Department of Plant Genetics, Breeding and Biotechnology, Agricultural
University, Nowoursynowska 166, 02-787 Warszawa, Poland
* E-mail: RAKOCZY@ALPHA.SGGW.WAW.PL |
|
Volume 7 (2002) pp 859-876 |
Title |
In Vivo PHOSPHORYLATION OF Drosophila melanogaster NUCLEAR
LAMINS DURING BOTH INTERPHASE AND MITOSIS |
Authors |
Ryszard Rzepecki1,2* and Paul A. Fisher1 |
Abstract |
To study phosphorylation of D. melanogaster nuclear lamins in vivo,
we used Kc tissue culture cells. Kc cells contain products of both lamin genes,
the lamin Dm0 gene encoding constitutive polypeptides expressed in almost all
cell types and the developmentally regulated lamin C gene. We grew K c cells in
low phosphate medium and labelled them with [32P]H3PO4. To obtain mitotic
cells we used vinblastine to arrest cells in metaphase. Cells were collected,
washed, lysed and resultant extracts fractionated in the presence of protein
phosphatase inhibitors. D. melanogaster proteins were then denatured by boiling
in SDS plus DTT, followed by immunoaffinity chromatography and SDS-PAGE
purification. As anticipated, we found that a CNBr fragment derived from the Nterminal
part of lamin Dm0-derivatives (amino acid residues 2-158; fragment A)
was phosphorylated during both interphase and mitosis. Interphase but not
mitotic phosphorylation was found on an internal CNBr fragment (derived from
the end of the central rod domain and the first part of the C-terminal lamin tail;
amino acid residues 385-548; fragment D). Interphase only phosphorylation was
also detected on another CNBr fragment derived from the extreme C-terminal
portion of lamin Dm0-derivatives (amino acid residues 549-622; fragment E).
To supplement these data, we used 2-D tryptic peptide mapping followed by
phosphorImager analysis. We routinely detected at least seven 'spots' derived
from interphase lamins but only a single mitotic lamin phosphopeptide. |
Address and Contact Information |
1The Department of Pharmacological Sciences, University Medical Center, The
State University of New York at Stony Brook, Stony Brook, NY 11794-8651,
USA,
2Institute of Biochemistry and Molecular Biology, University of Wrocław,
Przybyszewskiego Street 63/77, 51-148 Wrocław, Poland * Corresponding author, E-mail: rzepecki@ibmb.uni.wroc.pl, tel. (04871) 375 63 08
|
|
Volume 7 (2002) pp 877-883 |
Title |
METHYLATION OF THE ARGININE-GLYCINE-RICH REGION IN
THE FRAGILE X MENTAL RETARDATION PROTEIN FMRP
DIFFERENTIALLY AFFECTS RNA BINDING |
Authors |
Robert B. Denman |
Abstract |
The C-terminal end of the fragile X mental retardation protein
contains a stretch of amino acid residues that are enriched in arginine and
glycine. Recent studies using recombinant FMRPs have demonstrated that this
region participates in RNA binding in vitro, with calculated Kds ranging from 1-
10 nM depending on the RNA. It is known that other arginine-glycine-rich
proteins are subject to site-specific methylation by protein arginine
methyltransferases (PRMTs) that are particularly abundant in most cells. We
have demonstrated that the interaction of homoribopolymer mimetic RNAs with
human FMRP (hFMRP) made in PRMT-containing cell-free lysates is more
sensitive to increasing salt concentrations than recombinant hFMRP expressed in
bacteria. We have also shown that blocking methylation with adenosine-2', 3'-
dialdehyde (AdOx) alters homoribopolymer binding and hFMRP target mRNA
binding; both increases and decreases are observed as a function of methylation.
These data suggest that changes in PRMT activity that occur during
development, or arise via signal transduction may be a means of regulating the
binding of hFMRP to mRNA in vivo. |
Address and Contact Information |
New York State Institute for Basic Research, Department of Molecular Biology,
Laboratory of Biochemical Molecular Neurobiology, 1050 Forest Hill Road
Staten Island, NY 10314 |
|
Volume 7 (2002) pp 885-888 |
Title |
EVIDENCE FOR THE HYDROLYSIS OF TOPICAL APPLIED
LIPOSOMAL LIPIDS IN HUMAN STRATUM CORNEUM |
Authors |
Sebastian Zellmer |
Abstract |
Liposomes were incubated with an extract of human plantar stratum
corneum. The liposomal lipids were hydrolysed, if composed of soy-bean
phosphatidylcholine or phosphatidylglycerol. Rigid lipids were not degraded.
The temperature optimum of the hydrolysis was between 30-35°C. CaCl2
enhanced, while EDTA reduced the rate of hydrolysis, indicating that the
hydrolysis is due to a phospholipase A2. |
Address and Contact Information |
Labsoft Diagnostics AG, Robert-Franz-Ring 21, 06108 Halle, Germany
* E-mail: zellmer@labsoft.de |
|
Volume 7 (2002) pp 889-894 |
Title |
USE OF THE POST-INSERTION METHOD FOR THE FORMATION
OF LIGAND-COUPLED LIPOSOMES |
Authors |
Theresa M. Allen, Puja Sapra and Elaine Moase |
Abstract |
A new technique is described for the formation of ligand-targeted
liposomes that can be used with whole antibodies, antibody fragments, peptides
or other ligands. The ligands are coupled to polyethylene glycol micelles and
then transferred in a simple incubation step from the micelles into the outer
monolayer of pre-formed, drug-loaded liposomes. This versatile method allows a
combinatorial approach to the design of targeted liposomes that minimises
manufacturing complexities, allowing a variety of ligands to be inserted into a
variety of pre-formed liposomes containing a variety of drugs. This allows the
ligand-targeted therapeutics to be tailored to the needs of individual patients. |
Address and Contact Information |
Department of Pharmacology, University of Alberta, Edmonton, Alberta,
Canada T6G 2H7 |
|
Volume 7 (2002) pp 895-903 |
Title |
THE ROLE OF LIPID PHASE STRUCTURE IN THE INTERACTION
OF LACTATE DEHYDROGENASE WITH PHOSPHATIDYLSERINE.
ACTIVITY STUDIES |
Authors |
Grzegorz Terlecki1*, Elżbieta Czapińska1 and Jan Gutowicz2** |
Abstract |
Lactate dehydrogenase is one of the enzymes of the glycolytic path. It
has been shown to be able to bind in vitro to cellular membranes. The presence
of anionic phospholipids induces changes in the catalytic properties of the
enzyme similar to those found when the enzyme is bound to natural membranes.
In this study, a nonionic detergent (Tween 20), at concentrations not affecting
the catalytic activity of LDH, was used to study the role of the lipid supramolecular
structure in the interaction between pig skeletal muscle lactate
dehydrogenase and phosphatidylserine. Tween 20 changes the equilibrium of
concentrations between the lipid supra-molecular forms. The detergent at the
used concentration values did not alter the activity of the enzyme when it was
used on its own, but did diminish the level of inhibition induced by the studied
phospholipid. The obtained results showed that the interaction is reversible and
that the bilayer structure of the lipid is essential for the inhibition. |
Address and Contact Information |
1Department of Medical Biochemistry, Wrocław Medical University, Wrocław,
Poland,
2Department of Physico-Chemistry of Microorganisms, Institute of
Microbiology, University of Wrocław, Wrocław, Poland
*E-mail: terlecki@biochem.am.wroc.pl
**Corresponding author, E-mail: gutowicz@microb.uni.wroc.pl |
|
Volume 7 (2002) pp 905-910 |
Title |
FURTHER EVIDENCE FOR THE IMPORTANCE OF LIPID BILAYERS
IN THE INTERACTION BETWEEN LACTATE DEHYDROGENASE
AND PHOSPHATIDYLSERINE |
Authors |
Grzegorz Terlecki1* and Jan Gutowicz2** |
Abstract |
Lactate dehydrogenase (LDH) is one of the glycolytic enzymes,
which have been proved to have the capability to reverse non-specific adsorption
on cellular membranous structures in vitro, as well as on the structural proteins
of the contractile system of muscle cells. It has been suggested that this binding
may play a physiological role, as it alters the enzyme's kinetic properties. Our
previous studies on this enzyme showed that its interaction with some anionic
phospholipids reveals similar characteristics and similar effect on the activity of
the enzyme to those wich had been observed for the interaction with
membranous structures. Disruption of the lipid bilayers by nonionic detergent
(Tween 20) restored the enzyme activity inhibited by the presence of
phosphatidylserine (PS) liposomes. In this study, we used the measurement of
enzyme tryptophanyl fluorescence spectra to monitor the interaction and
possible changes in the enzyme conformation. The investigation provided
further evidence of the importance of the bilayer structure in this interaction.
Similarly to the effect on the activity of the enzyme, the addition of Tween 20
diminishes the quenching of the LDH tryptophanyl fluorescence, and finally
completely restores the fluorescence. |
Address and Contact Information |
1Department of Medical Biochemistry, Wrocław Medical University, Wrocław,
Poland,
2Department of Physico-Chemistry of Microorganisms, Institute of
Microbiology, University of Wrocław, Wrocław, Poland
*E-mail: terlecki@biochem.am.wroc.pl
**Corresponding author, E-mail: gutowicz@microb.uni.wroc.pl |
|
Volume 7 (2002) pp 911-917 |
Title |
PHYSICAL MAPPING OF rDNA IN DENDRANTHEMA
NANKINGENSE AND ITS CLOSE RELATED SPECIES BY
FLUORESCENT IN SITU HYBRIDIZATION |
Authors |
Wenkui Wang1*, Silan Dai1 and Maoxue Li2 |
Abstract |
Distribution of 18S-26S rDNA on the chromosomes of Dendranthema
nankingense and its two close-related species D. nankingense and D.
lavendulifolium was studied by fluorescent in situ hybridization with a JHD 2-
15A DNA clone. Six rDNA loci were found in D. nankingense, eight in D.
lavendulifolium, and twelve in D. indicum. The rDNA loci number and pattern
were applied to analyze the phylogenetic relationship of the three closely related
species |
Address and Contact Information |
1College of Landscape Architecture, Beijing Forestry University, Beijing
100083, P.R. China,
2College of Life Sciences, Peking University, Beijing
100871, P.R. China
* Corresponding author |
|
Volume 7 (2002) pp 919-922 |
Title |
LIPID-BASED ANTIFUNGAL AGENTS: A CONCISE OVERVIEW |
Authors |
Sevtap Arikan |
Abstract |
The development of lipid formulations of antifungal drugs has been a
remarkable progress in the systemic antifungal arena. The lipid-based
amphotericin B formulations; amphotericin B lipid complex (ABLC),
amphotericin B colloidal dispersion (ABCD), and liposomal amphotericin B (LAMB)
have been in clinical use since the 1990s. They are significantly less
nephrotoxic than the parent compound and can be safely used at higher doses.
The primary cost of these formulations is significantly high and the extent of
data related to their head-to-head comparison remains limited. The lipid
formulation of nystatin, liposomal nystatin, is another lipid-based polyene under
development. Available data concerning the in vitro activity, pharmacokinetic
profile, in vivo efficacy, and safety of these formulations are summarized in this
overview. |
Address and Contact Information |
Hacettepe University Medical School, Department of Microbiology and Clinical
Microbiology, Mycology Laboratory, 06100 Ankara, Turkey |
|
Volume 7 (2002) pp 923-927 |
Title |
CONSTRUCTION OF STABLE ANIONIC LIPOSOME-PLASMID
PARTICLES USING THE HEATING METHOD: A PRELIMINARY
INVESTIGATIONs |
Authors |
M. Reza Mozafari1, Celia J. Reed2, Christopher Rostron1, Cengiz Kocum3 and Erhan
Piskin3 |
Abstract |
Recent advances in liposome technology have resulted in the
production of effective drug delivery formulations, although toxicity concerns
remain. In order to overcome this problem we prepared anionic liposomes
without using any volatile organic solvent or detergent. Liposomes prepared by
this heating method (HM-liposomes) were characterised in terms of
morphology, stability and DNA incorporation efficiency. Scanning tunnelling
microscopy (STM) and optical microscopy were used to study the
morphological characteristics and size distribution of HM-liposomes.
Microscopic studies revealed formation of spherical bilayered structures with
stabilities of at least eight months and also enabled measuring the diameter and
the bilayer thickness of the vesicles. Plasmid DNA encapsulation efficiencies of
up to 70.3% were determined for HM-liposomes. |
Address and Contact Information |
1School of Pharmacy and Chemistry,
2School of Biomolecular Sciences,
Liverpool John Moores University, Liverpool, L3 3AF, England, UK.
3Hacettepe University, Chemical Engineering Department, Beytepe (06532),
Ankara, Turkey
* Corresponding author, E-mail: pacmmoza@livjm.ac.uk |
|
Volume 7 (2002) pp 929-935 |
Title |
ANTIOXIDATIVE ACTIVITY OF SOME PHENOXY AND
ORGANOPHOSPHOROUS COMPOUNDS |
Authors |
Dorota Bonarska, Halina Kleszczyńska and Janusz Sarapuk |
Abstract |
Experiments were performed in order to check whether biological
activity of some organophosphorous compounds widely applied as herbicides:
2,4-dichlorophenoxyacetic acid (1) and its sodium salt (2), Nphosphonomethylglycine
acid (3) and its sodium salt (4), diethyl 1-butylamino-
1-cyclohexanephosphonate (5) and diethyl 9-butylamino-9-fluorenephosphonate
(6) followed from their oxidative activity. The compounds studied differed in
their polarity and hydrophobicity. On the contrary, it was found that all
herbicides protected erythrocyte membranes against partial peroxidation induced
by UV irradiation. The effect was somewhat differentiated and followed the
sequence: 5 > 1 > 2 > 6 > 3 > 4.
The observed differences between the antioxidative activities of the compounds
are probably related to differences in their ability to incorporate into the lipid
phase of the erythrocyte membrane. Once incorporated, they change fluidity of
the membranes. The extent of the changes was determined in fluorescence
measurements. Polarization and anisotropy coefficients of erythrocyte
membranes modified by micromolar concentrations of herbicides at different
temperatures were measured for that purpose. Generally, they followed the
sequence found for antioxidative activity of the herbicides studied, which
confirms the assumption of close correlation between the depth of incorporation
of a herbicide into the erythrocyte membrane and its protective efficiency. |
Address and Contact Information |
Department of Physics and Biophysics, Agricultural University,
Norwida 25, 50-375 Wrocław, Poland |
|
Volume 7 (2002) pp 938 |
Late Abstract> |
Abstracts List |
INFLUENCE OF PIPERIDINE CHLORIDES DERIVATIVES ON THERMOTROPIC BEHAVIOUR OF PHOSPHATIDYLCHOLINE AND PHOSPHATIDYLCHOLINE/ CHOLESTEROL BILAYERS
Bożenna Różycka-Roszak, Edyta Woźniak and Zofia Dega-Szafran - p938
|
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|
Volume 7 (2002) pp 940 |
Erratum and Late Abstracts |
Abstracts List |
ERRATUM - p940
RATE CONSTANTS OF THE REACTION OF HYDROXYL RADICALS (°OH) WITH ALCOHOL DEHYDROGENASE (ADH) AND GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE (GAPDH)
Aleksandra Kowalczyk, Aneta Dudek and Mieczysław Puchała - p941
ELECTROPHYSIOLOGICAL STUDY ON THE MECHANISM OF MODULATION OF GABAERGIC SYNAPTIC CURRENTS BY HYDROGEN IONS
Maria Mandat, Ewa D. Żarnowska, Katarzyna Mercik and. Jerzy W. Mozrzymas - p942
INTEGRITY OF SPERMATOZOA AND THEIR MITOCHONDRIAL ENERGETIC STATUS IN RELATION TO MOTILITY OF SPERMATOZOA
Małgorzata Piasecka, Jerzy Kawiak, Zbigniew Szych, Maria Laszczyńska, Alicja Kozanecka and Blanka Kołodziej - p943
CHARACTERISATION OF INTEGRIN CONTENT IN HUMAN NORMAL AORTIC VALVES AND IN VALVES AFFECTED BY CALCIFIC AORTIC STENOSIS
Małgorzata Przybyło, Ewa Stępień, Roman Pfitzner, Anna Lityńska and Jerzy
Sadowski - p944
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