scholarly journals Cells Cultivation System and Preparation of the Purple Membranes for Bionanotechnology

2017 ◽  
Vol 14 (2) ◽  
pp. 679-684
Author(s):  
Daria O. Solovyeva ◽  
Vladimir A. Oleinikov ◽  
Sergei Yu. Zaitsev
Keyword(s):  
Functional Characterization ◽  
Exponential Phase ◽  
Halobacterium Salinarum ◽  
Major Protein ◽  
Optimal Conditions ◽  
Cultivation System ◽  
Cell Age ◽  
Working Volume ◽  
Purple Membranes

ABSTRACT: The purple membranes (PM) of the Halobacterium salinarum cells and bacteriorhodopsin (major retinal-containing trans-membrane protein of these bacteria are the most promising photosensitive biopolymers in terms of bionanotechnology, developing photosensitive devices, etc. The article is devoted to the improvement of the cultivation system for Halobacterium salinarum cells and the PM production; the study of the properties and functional characterization of bacteriorhodopsin - the biological components of the bionanomaterials. The optimal conditions for the production of the biomass are the following: the volume of incubation media must be 10% of the working volume (the volume of the cuvette); the cell “age” must be close to the end of the exponential phase of growth; the lighting must be maximum (4 light bulbs LD-20); the temperature must be 37°С; the time must be 8 days; the aeration must be 0.45 (L air)/(L of environment)/min. The yield of the product is about 5 g of biomass containing 45 mg of bacteriorhodopsin. The purple membranes and their major protein - bacteriorhodopsin were obtained with the required parameters.

scholarly journals Engineering and Production of the Light-Driven Proton Pump Bacteriorhodopsin in 2D Crystals for Basic Research and Applied Technologies

2020 ◽  
Vol 3 (3) ◽  
pp. 51
Author(s):  
Mirko Stauffer ◽  
Stephan Hirschi ◽  
Zöhre Ucurum ◽  
Daniel Harder ◽  
Ramona Schlesinger ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Proton Pump ◽  
Genetically Modified ◽  
Functional Characterization ◽  
Basic Research ◽  
Halobacterium Salinarum ◽  
Homologous Expression ◽  
Scientific Disciplines ◽  
2D Crystals ◽  
Purple Membranes

The light-driven proton pump bacteriorhodopsin (BR) from the extreme halophilic archaeon Halobacterium salinarum is a retinal-binding protein, which forms highly ordered and thermally stable 2D crystals in native membranes (termed purple membranes). BR and purple membranes (PMs) have been and are still being intensively studied by numerous researchers from different scientific disciplines. Furthermore, PMs are being successfully used in new, emerging technologies such as bioelectronics and bionanotechnology. Most published studies used the wild-type form of BR, because of the intrinsic difficulty to produce genetically modified versions in purple membranes homologously. However, modification and engineering is crucial for studies in basic research and, in particular, to tailor BR for specific applications in applied sciences. We present an extensive and detailed protocol ranging from the genetic modification and cultivation of H. salinarum to the isolation, and biochemical, biophysical and functional characterization of BR and purple membranes. Pitfalls and problems of the homologous expression of BR versions in H. salinarum are discussed and possible solutions presented. The protocol is intended to facilitate the access to genetically modified BR versions for researchers of different scientific disciplines, thus increasing the application of this versatile biomaterial.

scholarly journals Functional characterization of the central hydrophilic linker region of the urea transporter UT-A1: cAMP activation and snapin binding

2010 ◽  
Vol 298 (6) ◽  
pp. C1431-C1437 ◽  
Author(s):  
Abinash C. Mistry ◽  
Rickta Mallick ◽  
Janet D. Klein ◽  
Jeff M. Sands ◽  
Otto Fröhlich
Keyword(s):  
Functional Characterization ◽  
Major Protein ◽  
Phosphorylation Sites ◽  
Urea Transport ◽  
Transport Activity ◽  
Attachment Protein ◽  
Protein Receptor ◽  
Protein Variants ◽  
Protein Attachment

Of the three major protein variants produced by the UT-A gene (UT-A1, UT-A2, and UT-A3) UT-A1 is the largest. It contains UT-A3 as its NH2-terminal half and UT-A2 as its COOH-terminal half. When being part of UT-A1, UT-A3 and UT-A2 are joined by a segment, Lp, whose central part, Lc, is not part of UT-A3 or UT-A2 but is present only in UT-A1. Lc contains the phosphorylation sites S486 and S499 that are involved in protein kinase A-dependent activation, as well as the binding site for snapin, a protein involved in soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE)-mediated vesicle trafficking and fusion to the plasma membrane. We attached Lc to UT-A2 and UT-A3 to test how these phosphorylation sites influenced their urea transport activity. Adding Lc to UT-A2 conferred stimulation by cAMP to the cAMP-unresponsive UT-A2, and adding Lc to UT-A3 did not further enhance its already existing cAMP response. These findings suggest that the responsiveness to vasopressin that is observed with UT-A1 can be introduced into the unresponsive UT-A2 variant through the Lc segment that is unique to UT-A1. In UT-A3, however, the Lc segment plays no significant role in its activation by cAMP. In addition, the Lc segment also gave UT-A2 the ability to bind snapin and, in Xenopus oocytes, to be stimulated in its urea transport activity by snapin and syntaxins 3 and 4, in the same way as UT-A1.

Functional characterization of human brown adipose tissue metabolism

2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Functional Characterization ◽  
Human Infants ◽  
Positron Emission ◽  
Brown Adipose ◽  
Treatment Of Obesity ◽  
And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

Functional Characterization of PM6/13, a β3-specific (GPIIIa/CD61) Monoclonal Antibody that Shows Preferential Inhibition of Fibrinogen Binding over Fibronectin Binding to Activated Human Platelets

1998 ◽  
Vol 79 (01) ◽  
pp. 177-185 ◽  
Author(s):  
Ashia Siddiqua ◽  
Michael Wilkinson ◽  
Vijay Kakkar ◽  
Yatin Patel ◽  
Salman Rahman ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Functional Characterization ◽  
Human Platelets ◽  
Western Blots ◽  
Activated Platelets ◽  
Reducing Conditions ◽  
Fibronectin Binding

SummaryWe report the characterization of a monoclonal antibody (MAb) PM6/13 which recognises glycoprotein IIIa (GPIIIa) on platelet membranes and in functional studies inhibits platelet aggregation induced by all agonists examined. In platelet-rich plasma, inhibition of aggregation induced by ADP or low concentrations of collagen was accompanied by inhibition of 5-hydroxytryptamine secretion. EC50 values were 10 and 9 [H9262]g/ml antibody against ADP and collagen induced responses respectively. In washed platelets treated with the cyclooxygenase inhibitor, indomethacin, PM6/13 inhibited platelet aggregation induced by thrombin (0.2 U/ml), collagen (10 [H9262]g/ml) and U46619 (3 [H9262]M) with EC50 = 4, 8 and 4 [H9262]g/ml respectively, without affecting [14C]5-hydroxytryptamine secretion or [3H]arachidonate release in appropriately labelled cells. Studies in Fura 2-labelled platelets revealed that elevation of intracellular calcium by ADP, thrombin or U46619 was unaffected by PM6/13 suggesting that the epitope recognised by the antibody did not influence Ca2+ regulation. In agreement with the results from the platelet aggregation studies, PM6/13 was found to potently inhibit binding of 125I-fibrinogen to ADP activated platelets. Binding of this ligand was also inhibited by two other MAbs tested, namely SZ-21 (also to GPIIIa) and PM6/248 (to the GPIIb-IIIa complex). However when tested against binding of 125I-fibronectin to thrombin stimulated platelets, PM6/13 was ineffective in contrast with SZ-21 and PM6/248, that were both potent inhibitors. This suggested that the epitopes recognised by PM6/13 and SZ-21 on GPIIIa were distinct. Studies employing proteolytic dissection of 125I-labelled GPIIIa by trypsin followed by immunoprecipitation with PM6/13 and analysis by SDS-PAGE, revealed the presence of four fragments at 70, 55, 30 and 28 kDa. PM6/13 did not recognize any protein bands on Western blots performed under reducing conditions. However Western blotting analysis with PM6/13 under non-reducing conditions revealed strong detection of the parent GP IIIa molecule, of trypsin treated samples revealed recognition of an 80 kDa fragment at 1 min, faint recognition of a 60 kDa fragment at 60 min and no recognition of any product at 18 h treatment. Under similar conditions, SZ-21 recognized fragments at 80, 75 and 55 kDa with the 55kDa species persisting even after 18 h trypsin treatment. These studies confirm the epitopes recognised by PM6/13 and SZ-21 to be distinct and that PM6/13 represents a useful tool to differentiate the characteristics of fibrinogen and fibronectin binding to the GPIIb-IIIa complex on activated platelets.

Functional characterization of RUNX1 variants in the context of FPDMM

2019 ◽  
Author(s):  
M Decker ◽  
B Schlegelberger ◽  
T Illig ◽  
T Ripperger
Keyword(s):  
Functional Characterization
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