Protein and cell

A new branch of biology using experiments and computation to gain an understanding of biological systems (e.g. a cell), taking into account complex interactions of genes, proteins, and cell elements. 

Chattopadhaya and co-workers [162] recently reported another approach used to avoid some of the drawbacks associated with the use of FPs. The authors described a small molecule-based procedure that makes use of the unique reactivity between the cysteine residue at the N-terminus of a target protein and cell-permeable, thioester-based small molecule probes resulting in site-specific, covalent tagging of proteins. 

Patterson GH, Lippincott-Schwartz J (2002) A photoactivatable GFP for selective photolabeling of proteins and cells. Science 297 1873-1877... 

In summary, it appears that the apoptosis pathway can be regulated at various levels (the aforementionned description is far from being exhaustive), while many proteins and cell systems involved in this regulation remain to be discovered. Whereas the cascade of intracellular events implicated in experimentally-induced apoptosis has become more and more elucidated, it is worth noting that only few direct evidences arguing for the presence of an actual apoptosis in the brain of pa-... 

Compared with microporous and mesoporous materials, the larger, interconnected voids in macroporous materials potentially provide easier molecule transportation through the materials. This is of particular interest for the transport of large biomolecules (e.g., proteins and cells). The pore sizes in macroporous materials are usually from tens to hundreds of nanometers, and the pores are typically... 

When cells are suspended in a biological fluid or culture medium, both serum proteins and cells interact with the surface substrate. Serum protein adsorption behavior on SAMs has been examined with various analytical methods, including SPR [58-61], ellipsometry [13, 62, 63], and quartz QCM [64—66]. These methods allow in situ, highly sensitive detection of protein adsorption without any fluorescence or radioisotope labeling. SPR and QCM are compatible with SAMs that comprise alkanethiols. In our laboratory, we employed SPR to monitor protein adsorption on SAMs. 

Ostuni E, Yan L, Whitesides GM (1999) The interaction of proteins and cells with self-assembled monolayers of alkanethiolates on gold and silver. Colloids Surf B 15 3-30... 

Barrias CC, Martins MCL, Almeida-Porada G, Barbosa MA, Granja PL (2009) The correlation between the adsorption of adhesive proteins and cell behaviour on hydroxyl-methyl mixed self-assembled monolayers. Biomaterials 30 307-316... 

Fraker, P.J., and Speck Jr., J.C. (1978) Protein and cell membrane iodinations with a sparingly soluble chlo-roamide, l,3,4,6-tetrachloro-3a,6a-diphenylglycouril. Biochem. Biophys. Res. Comm. 80, 849-857. 

Sukhanova A et al (2004) Biocompatible fluorescent nanocrystals for immunolabeling of membrane proteins and cells. Anal Biochem 324 60-67... 

Palo, R. T., Sunnerheim, K., and Theander, 0.(1985). Seasonal variation of phenols, crude protein and cell wall content of birch Betulapendula Roth.) in relation to ruminant in vitro digestibility. Oecohgia 65,314—318. 

Molecular Recognition of Organized Systems by Protein and Cells... 

Mechanism of Action An antibacterial UTI agent that inhibits the synthesis of bacterial DNA, RNA, proteins, and cell walls by altering or inactivating ribosomal proteins. Therapeutic Effect Bacteriostatic (bactericidal at high concentrations). Pharmacokinetics Microcrystalline form rapidly and completely absorbed macrocrystalline form more slowly absorbed. Food increases absorption. Protein binding 40%. Primarily concentrated in urine and kidneys. Metabolized in most body tissues. Primarily excreted in urine. Removed by hemodialysis. Half-life 20-60 min. 

The increasing demand for synthetic biomaterials, especially polymers, is mainly due to their availability in a wide variety of chemical compositions and physical properties, their ease of fabrication into complex shapes and structures, and their easily tailored surface chemistries. Although the physical and mechanical performance of most synthetic biomaterials can meet or even exceed that of natural tissue (see Table 5.15), they are often rejected by a number of adverse effects, including the promotion of thrombosis, inflammation, and infection. As described in Section 5.5, biocompatibility is believed to be strongly influenced, if not dictated, by a layer of host proteins and cells spontaneously adsorbed to the surfaces upon their implantation. Thus, surface properties of biomaterials, such as chemistry, wettability, domain structure, and morphology, play an important role in the success of their applications. 

Weinberg, R.A. The retinoblastoma protein and cell cycle control (1995) Cell 81, 323-330... 

In this connection, it is to be noted that polyamine-modified po y(HEMA) surfaces exhibit surprisingly reduced interaction with blood proteins and cells (e.g. erythrocyte, platelet, lymphocyte etc.), as will be discussed in Sects. 4.3 and 4.4. The present author considers that there are probably closely related mechanisms between the suppressing effect of the poly(DIPAM) or (Methacrol)-modi-fied SPU and that of the polyamine-modified poly(HEMA) surfaces, with regard to their mode of interaction with the biological elements. 

Xenon is an odourless, colourless, non-explosive gas present in the atmospheres of both Earth and Mars in concentrations of approximately 0.08 ppm. Its density is approximately three times and its viscosity twice that of nitrous oxide. Like other noble gases, such as helium and argon, its outer electron shell contains the maximum number of electrons (8) making the molecule highly stable chemically. Despite this, its anaesthetic activity indicates that xenon binds to cell proteins and cell membrane constituents. 

Dash, P.R., Read, M.L., Fisher, K.D., et al. (2000). Decreased binding to proteins and cells of polymeric gene delivery vectors surface modified with a multivalent hydrophilic polymer and retargeting through attachment of transferrin. J. Biol. Chem., 275, 3793-3802. 

When strength-of-materials considerations are not signilicant design features of an anticipated device, one can use strategies that seek to prevent the adsorption of proteins and cells. As Table 6.1 illustrated, a strategy to accomplish this would be to use hydrophilic polymers. The interaction of proteins and surfaces is a complex subject and depends on the nature of the protein, associations with other proteins, time, shear, and other factors including the chemistry of the surface. 

Many derivatives of fluorescein containing a reactive group at the C-5 position are commercially available [11], Fluorescein isothiocyanate, for example, is widely used as protein tag [12]. These substances have essentially the same spectroscopic properties as the parent compound with the additional capability of binding covalently to proteins. Because of their high emission quantum yields, fluorescein conjugates are extensively used as tracers for microinjection in living cells to gather information on the structure and function of cells, localization of proteins, and cell-to-cell and intracellular diffusion [13-17]. 

With the development of neutral hydrophilic methacrylates in Prague, originally for contact lens applications in the early 60 s113>, considerable interest was generated in the application of these materials in the cardiovasular environment. The qualitative argument was that such soft, water-rich surfaces must be relatively non-traumatic to proteins and cells. The development of neutral hydrophilic polysaccharide-based particles for protein chromatography in the late 60 s provided evidence that such surfaces do indeed show minimal binding of proteins. 

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