HeLa cell membranes

The following aspects of viral glycoproteins have been reviewed glycoprotein and protein precursors to plasma membranes in vesicular stomatitis virus infected HeLa cells,membrane glycoproteins of enveloped viruses, membrane assembly, including the synthesis and intracellular processing of vesicular stomatitis virus, and the structure and replication of a-viruses. ... 

Treatment of HeLa cells with trypsin results in the liberation from the surface membrane of carbohydrate and protein. This does not affect the viability of the cells (Weiss, 1958) although as much as 22% reduction of dry mass was observed in experiments where only 20-60% of the total sugars were released (Shen and Ginsburg, 1968). The trypsin-accessible glycoproteins of the HeLa cell membrane do not, therefore, play a major structural role and would be among su-perstructural protein units described by the Danielli model. 

Trimethylaminodiphenylhexatriene chloride (TMADPH Fig. 7.45) is a fluorescent quaternary ammonium molecule that appears to permeate cell membranes [595]. TMADPH fluoresces only when it is in the bilayer, and not when it is dissolved in water. Therefore, its location in cells can be readily followed with an imaging fluorescence microscope. One second after TMADPH is added to the extracellular solution bathing HeLa cell types, the charged molecule fully equilibrates between the external buffer and the extracellular (outer) leaflet bilayer. Washing the cells for one minute removes >95% of the TMADPH from the outer leaflet. If the cells are equilibrated with TMADPH for 10 min at 37°C, followed by a one-minute wash that removed the TMADPH from the outer leaflet, the fluorescent molecule is... 

The same FRET pair was used to create a probe to monitor cathe-psins in HeLa cells [94], Since cathepsins are important in proteolysis within endosomes, it was in this case crucial to make the probe membrane-permeant. For this purpose a nona-arginine peptide was coupled to the N terminus to allow for endocytotic uptake. 

Fig. 12 CNTs act as a vector for drug delivery into living cells. After incubation of HeLa cells with AlexaFluor594-labeled SWNTs for 12 h at 37 °C, living cells were observed under confocal fluorescence microscope for a CNT uptake study, (a) Images show dual confocal detection of AlexaFluor594-SWNT (red) internalized into cells with the membrane stained by AlexaFluor488 (green), (b) Series of images of different z-focal scanning planes down through cells. (Adapted from [61])...

Radical polymerization of maleic anhydride and fullerene was used to obtain a new material, the photodynamic properties of which have been studied in vitro and in vivo. HeLa and bone tumor cell growth were inhibited by treatment with fullerene and light, so the polymer was tested on mice affected by bone tumor. After injection and irradiation, tumor size and weight were reduced and the mouse survival time was extended (Jiang and Li, 2007). The photodynamic properties of a supramolecular cucurbit[8]uril-fullerene complex have been studied by the same authors (Jiang and Li, 2006) who attributed HeLa cell death mainly to the damage of membrane phosphohpids and proteins. 

When the surface of the purified HeLa cell nucleus is observed by AFM (Fig. 5a), relatively smooth surface is seen, although many small projections and cavities can be identified (Fig. 5b). When the isolated nuclei are successively subjected to the detergent treatment and high-salt treatment on the glass substrate to remove the nuclear membrane and nucleoplasm, fibrous structures appear (Fig. 5c, d). A close examination by AFM classified the existence of granular structures ( 80 nm width)... 

Figure 7. A series of monoclonal antibodies raised against nuclear proteins. HeLa cells fixed with 4% paraformaldehyde were immunostained with monoclonal antibodies raised against nuclear proteins. The intracellular localization of these antigens are (a) dot inside the nucleolus, (b) whole nucleolus, (c) nuclear foci, (d) nucleoplasm, (e) the edge of the nucleus, (f) cytoplasm, (g) cytoskeleton, (h) plasma membrane, (i) mitochondria, (j) nucleus and cytoplasm, (k) nucleus and the paranuclear structure, and (1) paranuclear structure and nucleoplasm...

Exposure of HeLa cells to butyrate had no effect on the activity of GM3-sialidase when GM3 specifically labeled in the sialic acid residue was used as substrate (Fig. 3a). We were unable to detect any "ecto"-sialidase activity in either control or butyrate-treated cells (14) although others have postulated that such an enzyme is important in regulating plasma membrane gangliosides (15,16). In contrast, the activity of the specific sialyl transferase involved in GM3 biosynthesis increased over 20-fold following butyrate treatment (Fig. 3b). The effect was specific as activities of the other glycosphingolipid transferases that could be measured in HeLa cells were not altered in butyrate-treated cells (4,8,17). 

Peptide-induced membrane pcrmcabilization. (A) Stable EGFP expressing HeLa cells 315... 

Robbins, A.R., and R.M. Baker. (Na, K)ATPase activity in membrane preparations of ouabain-resistant HeLa cells. Biochemistry 16 5163-5168, 1977. 

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