Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Desensitization of the epidermal adenylate cyclase system: agonists and phorbol esters desensitize by independent mechanisms
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Molecular Cell Research 1093 (1991), S. 95-101 
    Details
    ISSN: 0167-4889
    Keywords: (Pig epidermis) ; Adenylate cyclase ; Agonist ; Desensitization ; Phorbol ester
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0167-4889(91)90143-L
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    CRP down-regulates adenylate cyclase activity by reducing the level of phosphorylated IIAGlc, the glucose-specific phosphotransferase protein, in Escherichia coli (1998)
    Springer
    Molecular genetics and genomics 259 (1998), S. 317-326 
    Details
    ISSN: 1617-4623
    Keywords: Key words cAMP level ; Adenylate cyclase ; CRP ; Phosphorylation state ; IIAGlc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cellular cAMP level is markedly down-regulated by cAMP receptor protein (CRP) in Escherichia coli. CRP regulates adenylate cyclase both at the level of transcription of its structural gene cya and at the level of enzyme activity. We established a method to determine the phosphorylation state of IIAGlc, the glucose-specific phosphotransferase protein, in intact cells. We found that IIAGlc exists predominantly in the unphosphorylated form in wild-type cells growing in LB medium, while it is largely phosphorylated in crp or cya cells. Disruption of the ptsG gene that codes for the membrane component of the major glucose transporter (IICBGlc), and/or the fruF gene coding for FPr (fructose-specific hybrid phosphotransferase protein), did not affect the phosphorylation state of IIAGlc. When IICBGlc was overproduced in the presence of glucose, the levels of both cAMP and phosphorylated IIAGlc in crp cells were concomitantly decreased to wild-type levels. In addition, when His-90 in IIAGlc was replaced by glutamine, both phosphorylation of IIAGlc and the overproduction of cAMP in crp cells were eliminated. We also found that extracts of crp + cells markedly stimulate dephosphorylation of IIAGlc-P in vitro. We conclude that CRP-cAMP down-regulates adenylate cyclase primarily by reducing the level of phosphorylated IIAGlc. The data suggest that unspecified proteins whose expression is under the control of CRP-cAMP are responsible for this regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380050818
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Protein kinase C-dependent modulation of stimulatory guanine nucleotide binding protein of fetal rat skin keratinocytes (1995)
    Springer
    Archives of dermatological research 288 (1995), S. 24-30 
    Details
    ISSN: 1432-069X
    Keywords: Key words G-protein ; Adenylate cyclase ; Phorbol ; esters ; Densensitization ; Keratinocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Although the protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA) has been known to induce heterologous desensitization of the epidermal adenylate cyclase, the precise mechanism of PMA action remains unknown. Effects of PMA on the receptor-G-protein-adenylate cyclase system of fetal rat skin keratinocytes (FRSK) were investigated. Choleratoxin catalysed the ADP ribosylation of 45 kDa and 52 kDa membrane proteins and islet activating protein (IAP) catalysed the ADP ribosylation of a 40 kDa membrane protein. Incubation of FRSK with PMA decreased the cholera toxin-catalysed ADP ribosylation of the membrane protein, but not the IAP-catalysed ADP ribosylation. The effect of PMA on the cholera toxin-catalysed ADP ribosylation was inhibited by the PKC inhibitor, H-7 (1-(5-isoquinolinesulfonyl)-2-methyl piperazine dihydrochloride). 1-Oleoyl-2-acetylglycerol (OAG), a membrane-permeable diacylglycerol analogue, also decreased the cholera toxin-catalysed ADP ribosylation, but 4- O -methyl PMA, a very weak PKC activator, had no effect. Keratinocytes are known to express the guanine nucleotide binding proteins, Gsα, Gi2α and Gi3α. Immunoblot analysis of the PMA-treated FRSK showed no detectable difference in the amount of Gsα, Gi2α, Gi3α or the β subunit of the G-protein. PMA significantly decreased the β-adrenergic adenylate cyclase response and cholera toxin-induced cyclic AMP accumulation, while it markedly increased forskolin-induced cyclic AMP accumulation. These results indicate that phorbol esters affect the stimulatory guanine nucleotide binding protein (Gs) of FRSK via a PKC-dependent pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004030050018
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Reverse osmosis with dynamically formed membranes from water-soluble polymers (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 1607-1618 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Membranes were dynamically formed from poly(acrylic acid), poly(1-methyl-2-vinylpyridinium iodide), and methylcellulose on a Millipore filter. The effects of the conditions of membrane formation on reverse osmosis performances and the membrane structure were investigated. The primary factors that affect membrane performance were ascertained to be the kind and concentration of salts and the pH of the preparing solutions, the concentration and the polymerization degree of the membrane materials, the pore size of filters, and the pressure and circulation velocity during membrane formation. Two types of dynamically formed membranes, the membranes inside the filter and the membranes on the filter, were distinguished.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1978.070220612
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Permselectivities of some aromatic compounds in organic medium through cellulose acetate membranes by reverse osmosis (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 2609-2620 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Reverse osmosis of some aromatic compounds in 1-propanol solution using porous cellulose acetate membranes and some factors which influence the organic solute permeability were investigated. Reverse osmosis data for a number of benzene derivatives showed that only phenol was rejected and the others were enriched. For the compounds with various substituent groups, the solute permeabilities have the following order; OH 〈 CH3 〈 H 〈 Cl 〈 NH2 〈 NO2. In the series of benzene, naphthalene, and anthracene, the permeability is related to the molar volume of solutes and varied as follows: benzene 〈 naphthalene 〈 anthracene. Generally speaking, there are two factors - a partition coefficient and a diffusion coefficient - for governing the permeation behavior through the membrane. Under the condition that no steric effect is exerted, the partition coefficient exclusively is a dominant factor. A good correlation between the partition coefficient of a particle and that of the membrane was pound. The partition coefficients are closely related to the dipole moment of solutes.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1978.070220917
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Radical polymerization of 3-cyano-3-ethoxycarbonylpropyl vinyl ether via addition-abstraction mechanism (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2839-2847 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080261020
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Phase separation in mixtures of poly(ethylene glycol monomethylether) and poly(propylene glycol) oligomers (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 29 (1991), S. 1419-1425 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Time-resolved light scattering was employed to investigate kinetics of phase separation in mixtures of poly (ethylene glycol monomethylether) (PEGE)/poly (propylene glycol) (PPG) oligomers. Phase diagrams for PEGE/PPG of varying molecular weights were established by means of cold point measurements. The oligomer mixtures reveal an upper critical solution temperature (UCST). Several temperature quench experiments were carried out with a 60/40 PEGE/PPG blend by rapidly quenching from a single phase (69°C) to two-phase temperatures (66-61°C) at 1°C intervals. As is typical for oligomer mixtures, the early stage of spinodal decomposition (SD) was not detected. The kinetics of phase decomposition was found to be dominated by the late stage of SD. Time-evolution of scattering intensity was analyzed in accordance with nonlinear and dynamical scaling theories. The time dependence of the peak intensity Im and the corresponding peak wavenumber qm was found to follow the power-law {Im(t)˜ tα, qm(t)˜ t-β} with the values of α = 3 ± 0.3 and β = 1 ± 0.2, which are very close to the values predicted by Siggia. This process has been attributed to a coarsening mechanism driven by surface tension. In the temporal scaling analysis, the structure function reveals university with time, suggesting self-similarity. Phase separation dynamics in 60/40 PEGE/PPG resembles the behavior predicted for off-critical mixtures.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1991.090291110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...