Interaction of polycations with cell-surface negative charges of epithelial cells

Singh, Ashok K.; Kasinath, Balakuntalam S.; Lewis, Edmund J.

doi:10.1016/0167-4838(92)90257-e

Cited by 71 publications

(43 citation statements)

References 12 publications

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“…A likely explanation of the above observations is that, since transferrin has a lower affinity for manganese than for iron (Tan & Woodworth, 1969;Scheuhammer & Cherian, 1985), some manganese, but not iron, can dissociate from transferrin in the extracellular medium or after binding to membrane receptors and can be taken up as ionic Mn2+, a process which is facilitated by extracellular KCI but inhibited by NaCl. When receptors for transferrin are (Morgan, 1988; (Jan & Chien, 1973;Cafiso, McLaughlin, McLaughlin & Winiski, 1989;Singh, Kasinath & Lewis, 1992 The inhibition produced by amiloride and NaCl suggests that Mn2+ transport is competing with a Na+ transport process since amiloride is known to inhibit many such processes (Benos, Warnock & Smith, 1992 port, the sensitivity of low affinity Mn2+ transport to the various inhibitors examined in this investigation is very similar to that of the antiport (Flatman, 1991;Gunther, 1993). Hence, one may conclude that Mn2+ can be transported into rabbit erythroid cells by the same mechanism.…”

Section: Mna+ Uptake From Nacl Solutionsupporting

confidence: 53%

Mechanisms of manganese transport in rabbit erythroid cells.

Chua

Stonell

Savigni

et al. 1996

The Journal of Physiology

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1. The mechanisms of manganese transport into erythroid cells were investigated using rabbit reticulocytes and mature erythrocytes and 54Mn‐labelled MnCl2 and Mn2‐transferrin. In some experiments iron uptake was also studied. 2. Three saturable manganese transport mechanisms were identified, two for Mn2+ (high and low affinity processes) and one for transferrin‐bound manganese (Mn‐Tf). 3. High affinity Mn2+ transport occurred in reticulocytes but not erythrocytes, was active only in low ionic strength media such as isotonic sucrose and had a Km of 0.4 microM. It was inhibited by metabolic inhibitors and several metal ions. 4. Low affinity Mn2+ transport occurred in erythrocytes as well as in reticulocytes and had Km values of approximately 20 and 50 microM for the two types of cells, respectively. The rate of Mn2+ transport was maximal in isotonic KCl, RbCl or CsCl, and was inhibited by NaCl and by amiloride, valinomycin, diethylstilboestrol and other ion transport inhibitors. The direction of Mn2+ transport was reversible, resulting in Mn2+ efflux from the cells. 5. The uptake of transferrin‐bound manganese occurred only with reticulocytes and depended on receptor‐mediated endocytosis of Mn‐Tf. 6. The characteristics of the three saturable manganese transport mechanisms were similar to corresponding mechanisms of iron uptake by erythroid cells, suggesting that the two metals are transported by the same mechanisms. 7. It is proposed that high affinity manganese transport is a surface representation of the process responsible for the transport of manganese across the endosomal membrane after its release from transferrin. Low affinity transport probably occurs by the previously described Na(+)‐Mg2+ antiport, and may function in the regulation of intracellular manganese concentration by exporting manganese from the cells.

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Section: Mna+ Uptake From Nacl Solutionsupporting

confidence: 53%

Mechanisms of manganese transport in rabbit erythroid cells.

Chua

Stonell

Savigni

et al. 1996

The Journal of Physiology

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“…The surface is negatively charged due to carboxylic groups of the sialic acid of glycoproteins, the sulfate groups of proteoglycans, and the phosphate groups of glycerophosphates. [14] The polyanions on the cell surface are loosely fixed, maintaining a significant degree of conformational freedom and behaving more like soluble polymers rather than like a rigid polymer matrix.…”

Section: Discussionmentioning

confidence: 99%

Influence of Complexing Polyanions on the Thermostability of Basic Proteins

Ivinova

Izumrudov

Muronetz

et al. 2003

Macromolecular Bioscience

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Lysozyme (Lyz), chymotrypsinogen (Cht), and glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) were used as model proteins capable of forming water‐soluble polyelectrolyte complexes with linear synthetic polyanions. The complex formation with sodium poly(methacrylate) (PMA), sodium poly(acrylate) (PAA), sodium poly(anetholsulfonate) (PAS), and potassium poly(vinylsulfate) (PVS) markedly reduced the temperature of protein denaturation, Tmax, as determined by differential scanning calorimetry (DSC). The effect of sodium poly(styrenesulfonate) (PSS) on Lyz was so drastic that the protein melting peak was not observed at all during DSC measurements. The temperature shift, most pronounced for Lyz, increased upon substitution of the polyanions according to the following series: PMA < PVS < PAA < PAS < PSS. Decomposition of the complexes by addition of either sodium chloride or poly(N‐ethyl‐4‐vinylpyridinium) cation completely restored the initial Tmax of the protein (except for PSS and PAS). The complex formation slightly affected the enzyme activity up to temperatures close to Tmax of the polyanion–protein complex. On further heating, the activity of the complex decreased steeply, whereas the free enzyme maintained a high activity. The data obtained strongly suggest that the protein–polyelectrolyte interactions in solution, while leaving the thermostability and activity of the proteins practically unaffected over a rather wide temperature range, result in the effective denaturation of proteins once a certain critical temperature is achieved. This finding appears to be crucial for further development of immobilized enzymes in biotechnology and essential for understanding mechanisms and principles of the functioning of proteins immobilized on charged matrices in vivo.Temperature dependence of partial heat capacity ΔCp of free Lyz and Lyz in the mixtures with PMA.magnified imageTemperature dependence of partial heat capacity ΔCp of free Lyz and Lyz in the mixtures with PMA.

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“…Preincubation of 293 cells with Polybrene, a ϳ7,500-Da polycation that has been previously used to neutralize anionic charges on the cell surface (63), completely abrogated the disadvantages of short-shafted Ad5S and Ad5/9S vectors in cell binding, resulting in binding rates comparable to those for Ad5L and Ad5/9L (Fig. 8A).…”

Section: Construction Of Chimeric Ad Vectorsmentioning

confidence: 92%

Dependence of Adenovirus Infectivity on Length of the Fiber Shaft Domain

Shayakhmetov

Lieber

2000

J Virol

178

166

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One of the objectives in adenovirus (Ad) vector development is to target gene delivery to specific cell types. Major attention has been given to modification of the Ad fiber knob, which is thought to determine virus tropism. However, among the human Ad serotypes with different tissue tropisms, not only the knob but also the length of the fiber shaft domain varies significantly. In this study we attempted to delineate the role of fiber length in coxsackievirus-adenovirus receptor (CAR)-and non-CAR-mediated infection. A series of Ad serotype 5 (Ad5) capsid-based vectors containing long or short fibers with knob domains derived from Ad5, Ad9, or Ad35 was constructed and tested in adsorption, internalization, and transduction studies. For Ad5 or Ad9 knobpossessing vectors, a long-shafted fiber was critical for efficient adsorption/internalization and transduction of CAR/␣v integrin-expressing cells. Ad5 capids containing short CAR-recognizing fibers were affected in cell adsorption and infection. In contrast, for the chimeric vectors possessing Ad35 knobs, which enter cells by a CAR/␣v integrin-independent pathway, fiber shaft length had no significant influence on binding or infectibility on tested cells. The weak attachment of short-shafted Ad5 or Ad9 knob-possessing vectors seems to be causally associated with a charge-dependent repulsion between Ad5 capsid and acidic cell surface proteins. The differences between short-and long-shafted vectors in attachment or infection were abrogated by preincubation of cells with polycations. This study demonstrates that the fiber-CAR interaction is not the sole determinant for tropism of Ad vectors containing chimeric fibers. CAR-and ␣v integrin-mediated infections are influenced by other factors, including the length of the fiber shaft.Most recombinant adenovirus (Ad) vectors currently used for in vitro and in vivo gene transfer are based on serotype 5 (Ad5). Efficient transduction with these vectors requires the presence of appropriate cell receptors for binding and/or internalization. High-affinity binding of Ad5 is mediated through the coxsackievirus and Ad receptor (CAR) (6, 7, 68). Ad5 internalization requires an additional interaction of RGD motifs on the penton base with ␣v␤3 and/or ␣v␤5 integrins on the cell surface (32,39,48,71).Safety and efficacy of in vivo applications of Ad vectors require targeting to specific tissues, which is precluded by the widespread distribution of CAR and ␣v integrins. On the other hand, a number of tissues, which represent important targets for gene therapy, are refractory to Ad5 infection due to the lack of these receptors (11,64,70,73). Therefore, modification of tropism is one of the central tasks in Ad vector development. One strategy to retarget Ad5 vectors involves complexing the Ad capsid with bispecific antibodies (18, 70) or peptide ligands (17, 58). Another approach is genetic modification of the Ad5 fiber knob (43), which is aimed toward the incorporation of specific peptide ligands into the Ad5 knob with simultaneous abrogat...

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Interaction of polycations with cell-surface negative charges of epithelial cells

Cited by 71 publications

References 12 publications

Mechanisms of manganese transport in rabbit erythroid cells.

Mechanisms of manganese transport in rabbit erythroid cells.

Influence of Complexing Polyanions on the Thermostability of Basic Proteins

Dependence of Adenovirus Infectivity on Length of the Fiber Shaft Domain

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