Living cells

An applied field of biology that involves the use of living organisms and bioprocesses in engineering, technology, medicine and other fields requiring bioproducts. (http://en.wikipedia.org/wiki/Biotechnology) It is the products and exploitation from other fundamental sciences.Traditional Biotechnology Traditional biotechnology refers to a number of ancient ways of using living organisms to make new products or modify existing ones. In its broadest definition, traditional biotechnology can be traced back to human's transition from hunter-gatherer to farmer.

29p zingzing09 24-04-2013 63 8   Download

Polyphosphate polymer (polyP) plays a very important role in every living cell. Synthesis of this linear polymer of phosphate (Pi) residues is catalyzed by the polyphosphate kinase (PPK) enzyme.

16p nutifooddau 27-01-2019 18 2   Download

P-glycoprotein (Pgp), a membrane pump often responsible for the multidrug resistance of cancer cells, undergoes conformational changes in the presence of substrates/modulators, or upon ATP depletion, reflected by its enhanced reactivity with the UIC2 monoclonal antibody. When the UIC2-shift was elicited by certain modulators (e.g. cyclosporin A or vinblastine, but not with verapamil or Tween 80), the subsequent binding of other monoclonal anti-Pgp Ig sharing epitopes with UIC2 (e.g. MM12.10) was abolished [Nagy, H., Goda, K., Arceci, R., Cianfriglia, M., ´ Mechetner, E. & Szabo Jr, G.

6p system191 01-06-2013 62 7   Download

BTG/Tob family proteins, which are characterized by similarities in their N-terminal BTG/Tob homology domains, control cell growth negatively. Among the BTG/ Tob family members, BTG2/TIS21/PC3 proteins have been reported to have short lives and to be degraded by the proteasome. However, the mechanisms regulating the stabilities of other BTG/Tob family proteins have not yet been clarified.

9p research12 01-06-2013 31 4   Download

The osmoregulated periplasmic glucans (OPGs) produced byRhodobacter sphaeroides, a free-living organism, were isolated by trichloracetic acid treatment and gel permeation chromatography. Compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance.R. sphaeroidespredominantly synthesizes acyclic glucan containing 18 glucose residues that canbe substituted by one to seven succinyl esters residues at the C6position of some of the glucose residues, and by one or two acetyl resi-dues....

9p research12 29-04-2013 37 1   Download

Traditional analyses of the control and regulation of steady-state concentrations and fluxes assume the activities of the enzymes to be constant. In living cells, a hierar-chical control structure connects metabolic pathways to signal-transduction and gene-expression. Consequently, enzyme activities are not generally constant. This would seem to compromise analyses of control and regulation at the metabolic level.

10p research12 23-04-2013 49 2   Download

Reactionof certainpeptides andproteinswithsingletoxygen (generated by visible light in the presence of rose bengal dye) yields long-lived peptide and protein peroxides. Incubation of these peroxides with glyceraldehyde-3-phosphate dehy-drogenase, in the absence of addedmetal ions, results in loss of enzymatic activity. Comparative studies with a range of peroxides have shown that this inhibition is concentration, peroxide, and time dependent, with H2O2less ecient than some peptide peroxides.

10p research12 23-04-2013 39 4   Download

The expression of the major protein kinase C substrate MARCKS (myristoylatedalanine-richCkinase substrate) is controlled by the stability of its mRNA. While the MARCKS mRNA is long living in quiescent fibroblasts (t1/2¼14 h), its half-life time is drastically reduced (t1/2¼2 h) in cells treated with phorbol esters to activate protein kinase C (PKC) or treatedwith growth factors. In a first step to study the underlying mechanism we identified both acis-element on the MARCKS mRNA and the cor-responding trans-acting factors. ...

16p tumor12 20-04-2013 40 3   Download

A new baculovirus-based fluorescence resonance energy transfer (Bv-FRET) assay for measuringmultimerization of cell surface molecules in living cells is described. It has been demonstrated that gonadotropin-releasing hormone recep-tor (GnRH-R) was capable of forming oligomeric com-plexes in the plasma membrane under normal physiological conditions. The mouse gonadotropin-releasing hormone receptor GnRH-R was used to evaluate the efficiency and potential applications of this assay.

9p fptmusic 12-04-2013 58 4   Download

We found that Notched-fin eelpout, which lives off the north east coast of Japan, expresses an antifreeze protein (AFP). The liver of this fish contains DNAs that encode at least 13 type III AFP isoforms (denoted nfeAFPs). The primary sequences of the nfeAFP isoforms were categor-ized into SP- and QAE-sephadex binding groups, and the latter were fur-ther divided into two subgroups, QAE1 and QAE2 groups. Ice crystals observed in HPLC-pure nfeAFP fractions are bipyramidal in shape with different ratios ofc andaaxes, suggesting that all the isoforms are able to bind ice....

11p awards 05-04-2013 44 3   Download

Why are there so many dimeric proteins and enzymes? While for hetero-dimers a functional explanation seems quite reasonable, the case of homo-dimers is more puzzling. The number of homodimers found in all living organisms is rapidly increasing. A thorough inspection of the structural data from the available literature and stability (measured from denatura-tion–renaturation experiments)

0p awards 05-04-2013 40 2   Download

In view of the increasing number of reported concentration oscillations in living cells, methods are needed that can identify the causes of these oscillations. These causes always derive from the influences that concentrations have on reaction rates. The influences reach over many molecular reaction steps and are defined by the detailed molecular topology of the network. So-called
autoinfluence paths, which quantify the influence of one molecular species upon itself through a particular path through the network, can have positive or negative values....

11p awards 05-04-2013 46 5   Download

In living organisms, Ca 2+ signalling is central to cell physi-ology. The Ca 2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N¢,N¢-tetraaceticacid (BAPTA) hasbeenwidelyusedas a probe to test the role of calcium in a large variety of cell functions. Here we show that inmost cell types BAPTAhas a potent actin and microtubule depolymerizing activity and that this activity is completely independent of Ca 2+ chela-tion. Thus, the depolymerizing effect of BAPTA is sharedby a derivative (D-BAPTA) showing a dramatically reduced calcium chelating activity....

10p awards 05-04-2013 30 4   Download

Riftia pachyptila(Vestimentifera) is a giant tubeworm living around the volcanic deep-sea vents of the East Pacific Rise. This animal is devoid of a digestive tract and lives in an intimate symbiosis with a sulfur-oxidizing chemoauto-trophic bacterium. This bacterial endosymbiont is localized in the cells of a richly vascularized organ of the worm: the trophosome.

10p awards 05-04-2013 46 3   Download

Sponges (phylum Porifera) live in a symbiotic relationship with microorganisms, primarily bacteria. Until now, mole-cular proof for the capacity of sponges to recognize fungi in the surroundingaqueousmilieuhas not beenavailable.Here we demonstrate, for the demospongeSuberites domuncula (Porifera, Demospongiae, Hadromerida), a cell surface receptor that recognizes (1fi3)-b-D-glucans, e.g. curdlan or laminarin. This receptor, the (1fi3)-b-D-glucan-binding protein, was identified and its cDNA analysed.

14p dell39 03-04-2013 37 5   Download

Proteins from organisms living in extreme conditions are of particular interest because of their potential for being templates for redesign of enzymes both in biotechnological and other industries. The crystal struc-ture of a proteinase K-like enzyme from a psychrotroph Serratiaspecies has been solved to 1.8 A˚ .

11p dell39 27-03-2013 39 3   Download

Rheumatoid arthritis (RA) is a systemic, chronic inflammatory disease that affects 0.5–1% of the population. RA causes progressive joint destruction that leads to the restriction of activities of daily living and deterioration of quality of life.

7p galaxyss3 07-03-2013 32 3   Download

Autophagy is a nonspecific bulk degradation pathway for long-lived cyto-plasmic proteins, protein complexes, or damaged organelles. This process is also a major degradation pathway for many aggregate-prone, disease-cau-sing proteins associated with neurodegenerative disorders, such as mutant huntingtin in Huntington’s disease. I

8p galaxyss3 07-03-2013 45 5   Download

Biological functions governed by the circadian clock are the evident result of the entrainment operated by the earth’s day and night cycle on living organisms. However, the circadian clock is not unique, and cells and organisms possess many other cyclic activities.

8p media19 06-03-2013 39 4   Download

Detailed understanding of the dynamics of living systems requires a means to monitor, in real time, changes in the levels of key components in response to specific stimuli. Applications involving cultured cells, tissue slices and implantation in living systems are discussed.

10p media19 04-03-2013 20 1   Download