Ca2+-Mediated Interaction between Dextran Sulfate and Dimyristoyl-sn-Glycero-3-Phosphocholine Surfaces Studied by 2H Nuclear Magnetic Resonance

Huster, Daniel; Arnold, Klaus

doi:10.1016/s0006-3495(98)77579-4

Cited by 40 publications

(43 citation statements)

References 42 publications

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“…Moreover, the data suggest that PA, and heparin, in particular, continue to possess a negative net charge even in 100 mM Ca 2þ solution (27). Because heparins also require the presence of divalent cations in the bulk to affect the channel (27), we considered the possibility that heparins bind to the membrane, in agreement with the calcium-bridge mechanism suggested in the literature (8,30,41).…”

Section: Liposomessupporting

confidence: 57%

Interaction of Heparins and Dextran Sulfates with a Mesoscopic Protein Nanopore

Teixeira

Merzlyak

Valeva

et al. 2009

Biophysical Journal

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A mechanism of how polyanions influence the channel formed by Staphylococcus aureus alpha-hemolysin is described. We demonstrate that the probability of several types of polyanions to block the ion channel depends on the presence of divalent cations and the polyanion molecular weight and concentration. For heparins, a 10-fold increase in molecular weight decreases the half-maximal inhibitory concentration, IC(50), nearly 10(4)-fold. Dextran sulfates were less effective at blocking the channel. The polyanions are significantly more effective at reducing the conductance when added to the trans side of this channel. Lastly, the effectiveness of heparins on the channel conductance correlated with their influence on the zeta-potential of liposomes. A model that includes the binding of polyanions to the channel-membrane complex via Ca(2+)-bridges and the asymmetry of the channel structure describes the data adequately. Analysis of the single channel current noise of wild-type and site-directed mutant versions of alpha-hemolysin channels suggests that a single polyanion enters the pore due to electrostatic forces and physically blocks the ion conduction path. The results might be of interest for pharmacology, biomedicine, and research aiming to design mesoscopic pore blockers.

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Section: Liposomessupporting

confidence: 57%

Interaction of Heparins and Dextran Sulfates with a Mesoscopic Protein Nanopore

Teixeira

Merzlyak

Valeva

et al. 2009

Biophysical Journal

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“…The positive side of the dipole is pushed out into the aqueous phase (Scherer and Seelig 1989), and, due to electrostatic interaction with the negatively charged phosphate groups of DNA, the aggregate is formed. However, in the presence of negatively charged polyelectrolytes, the cation binding of the lipid -polyelectrolyte complex is drastically enhanced, as shown by Huster and Arnold (1998) for DMPC/dextran sulfates (DS)/calcium system. In addition to the formation of calcium bridges between lipid's phosphate groups and the sulfate groups of DS, the authors suggest the accumulation of calcium in the diffuse double layer at the lipid-DS plane, according to the Gouy-Chapman theory.…”

Section: Dscmentioning

confidence: 99%

Interaction of short-fragmented DNA with dipalmitoylphosphatidylcholine bilayers in presence of zinc

Uhrı́ková¹,

Pullmannová²,

Bastos³

et al. 2009

gpb

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The structure and temperature behaviour of the DNA+dipalmitoylphosphatidylcholine (DPPC) bilayer as a function of ZnCl 2 concentration were examined using differential scanning calorimetry (DSC), small-angle neutron scattering (SANS) and small-angle X-ray diffraction (SAXD). Experiments revealed the coexistence of two lamellar phases in the mixture: the L PC phase, formed due to Zn 2+ binding to the DPPC bilayers, and the condensed lamellar phase L DNA+PC with DNA strands packed between the DPPC bilayers. With increasing concentration of zinc, the temperature of the gel -liquid-crystal phase transition of DPPC increases in both phases, and the volume fraction of L DNA+PC phase decreases. In the gel state (at 20°C), the repeat distance of L DNA+PC phase is constant, d DNA+PC ~ 8.3 nm, up to 20 mmol/l of ZnCl 2 , and increases for higher concentrations of the salt. The periodicity of the L PC lamellar phase decreases substantially with the increasing concentration of the salt in the mixture. In the liquid-crystalline state, concentrations above 20 mmol/l ZnCl 2 promote the dissolution of the L DNA+PC phase into DPPC + Zn 2+ unilamellar vesicles and DNA is neutralized by Zn 2+ ions. The screening of Zn 2+ charge and the formation of a diffuse double layer due to increasing ionic strength of solution are responsible for the observed changes.

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“…Positively charged stretches of amino acids can bind directly to the head groups of phospholipids as in the case of myosin and other proteins with polybasic clusters (Doberstein and Pollard, 1992;Reizes et al, 1994;Areas et al, 1998;Heo et al, 2006). Alternatively or in addition, negatively charged amino acids, such as in the highly phosphorylated Nopp140 repeats, can interact with phospholipids via calcium bridges as in the case of synaptogamin I, PKC␤, and dextran sulfate (Huster and Arnold, 1998;Zhang et al, 1998;Huster et al, 1999;Nalefski et al, 2001). Because the lumen of the ER and the nuclear envelope is highly enriched in calcium and because R-rings contain calcium channels, such as the IP 3 receptor (Isaac et al, 2001), we tested if Nopp140 is a calcium-binding protein by using a blot overlay technique (Maruyama et al, 1984).…”

Section: A Role For Calcium In R-ring Biogenesismentioning

confidence: 99%

The Nucleolar Channel System of Human Endometrium Is Related to Endoplasmic Reticulum and R-Rings

Kittur¹,

Zapantis

Aubuchon

et al. 2007

MBoC

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The nucleolar channel system (NCS) is a well-established ultrastructural hallmark of the postovulation endometrium. Its transient presence has been associated with human fertility. Nevertheless, the biogenesis, composition, and function of these intranuclear membrane cisternae are unknown. Membrane systems with a striking ultrastructural resemblance to the NCS, termed R-rings, are induced in nuclei of tissue culture cells by overexpression of the central repeat domain of the nucleolar protein Nopp140. Here we provide a first molecular characterization of the NCS and compare the biogenesis of these two enigmatic organelles. Like the R-rings, the NCS consists of endoplasmic reticulum harboring the marker glucose-6-phosphatase. R-ring formation initiates at the nuclear envelope, apparently by a calcium-mediated Nopp140-membrane interaction, as supported by the calcium-binding ability of Nopp140, the inhibition of R-ring formation by calcium chelators, and the concentration of Nopp140 and complexed calcium in R-rings. Although biogenesis of the NCS may initiate similarly, the reduced presence of complexed calcium and Nopp140 suggests the involvement of additional factors. INTRODUCTIONFor close to half a century, the nucleolar channel system (NCS) has been known as an ultrastructural hallmark of the postovulation human endometrium (Dubrauszky and Pohlmann, 1960;Clyman, 1963;Moricard and Moricard, 1964;Terzakis, 1965). It consists of several layers of tubular membrane cisternae in the nuclei of endometrial epithelial cells and is often associated with the nuclear envelope and nucleoli, hence the name (for a review see Spornitz, 1992). This organelle appears during a 3-to 4-d window in the midsecretory phase of the menstrual cycle when the endometrium is receptive to implantation of the fertilized egg (Clyman, 1963;Gordon, 1975). Oral contraceptives and intrauterine devices interfere with the timing and/or overall appearance of the NCS (Wynn, 1967;Feria-Velasco et al., 1972;Azadian-Boulanger et al., 1976;van Santen et al., 1988;Dockery et al., 1997). Several cases of unexplained primary infertility have been characterized by the absence or delayed development of NCSs as the only ultrastructural alteration in endometrial epithelial cells (Kohorn et al., 1972;Gore and Gordon, 1974;Dockery et al., 1996). This and other correlative evidence suggests a role for the NCS in the preparation of the uterine surface for embryo implantation and points to the NCS as a long sought after marker for human receptivity. Nevertheless, despite this tantalizing data and the detailed ultrastructural description of the NCS, it has resisted molecular characterization. Here we provide first insights as to the composition of this enigmatic organelle.On the basis of their remarkable ultrastructural resemblance to the NCS, we previously characterized membrane systems, R-rings, that are induced in nuclei of tissue culture cells by overexpression of the nucleolar protein Nopp140 (Isaac et al., 1998;Isaac et al., 2001). Nopp140 functions as a chaper...

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Ca2+-Mediated Interaction between Dextran Sulfate and Dimyristoyl-sn-Glycero-3-Phosphocholine Surfaces Studied by 2H Nuclear Magnetic Resonance

Cited by 40 publications

References 42 publications

Interaction of Heparins and Dextran Sulfates with a Mesoscopic Protein Nanopore

Interaction of Heparins and Dextran Sulfates with a Mesoscopic Protein Nanopore

Interaction of short-fragmented DNA with dipalmitoylphosphatidylcholine bilayers in presence of zinc

The Nucleolar Channel System of Human Endometrium Is Related to Endoplasmic Reticulum and R-Rings

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