EntS protein

With the human CYP17A1 gene, the homeo-domain protein Pbxl was shown to interact with protein kinase A in the cyclic AMP-dependent regulation (at —250/—241) . Further analysis showed interaction at a cyclic AMP-related site (-80/-40) by SF-1 (ref [1228]). Further, interactions were shown for Spl and Sp3 (-227/-184) and NF-IC (-107/-85 and — 178/—152). SF-1 vide supra) also interacts with p54", NonO, and protein-associated splicing factor °. The ACTH/cyclic AMP response is dependent upon phosphatase activity, as well as kinase activity - The cyclic AMP-dep)end-ent protein kinase enhances transcription via MKP-1 activation, involving phosphorylation of SF-1 (ref [1233]). 

Tlie polypeptide compositions of the PS I and CCI pi ent-protein bands is similar to those obtained previously for other organisms (1,3,7,13) Note, however, that PS I does not contain any LHC Ilb subunits, a frequent contaminant of PS I preparations, wfrich we ascribe to our not using Triton-XlOO for the purification of PS I. The polypeptide composition of the LHC I pigmented band represents those PS I protein subunits that are not contained in CC I. This then indicates that the LHC I pigment-protein complex indeed contains components of the PS I antenna. The 21kD polypeptide, the LHC Ib apoprotein, is often seen as a doublet. 

Analysis of the relative areas under the stable boundaries indicated that the composition of the complexes 1 and 2 was constant and that the distribution between the components was a linear function of the mixing ratio. The first complex, AD , containing 0.22 g. SDS per g. protein (or the equivalent of half the cationic groups of serum albumin) corresponds in composition to the precipitate at the minimum detei ent/ protein ratio requisite for complete precipitation. The second complex, AD2n, contains just twice as much SDS (the equivalent of the total acidbinding capacity) and corresponds in composition to the precipitate obtained at the maximum detergent/protein ratio yielding complete... 

Electrophoresis is used primarily to analyze mix tures of peptides and proteins rather than individual ammo acids but analogous principles apply Because they incorporate different numbers of ammo acids and because their side chains are different two pep tides will have slightly different acid-base properties and slightly different net charges at a particular pH Thus their mobilities m an electric field will be differ ent and electrophoresis can be used to separate them The medium used to separate peptides and proteins is typically a polyacrylamide gel leading to the term gel electrophoresis for this technique... 

Most packages will happily take Cartesian coordinates or Z-matrices, but you ought to be aware of the Z-matrix. The point is that Cartesian coordinates can be obtained from sources such as the Protein Data Bank (these come in files with. pdb or. ent extensions). 

The ent-fes-fep gene cluster is necessary for the synthesis of enterobactin and transport of the iron loaded siderophore. The fes gene product was shown to be necessary for utilization of the siderophore-bound iron inside the cell. The protein has an esterase activity which cleaves the ester bonds of the cyclic 2,3-dihydroxybenzoylserine ester in enterobactin. However, the esterase activity of Fes does not seem to be important for iron mobilization since Fes is also necessary for the utilization of iron from enterobactin analogues which do not have ester bonds (Heidinger et ah, 1983). No reductase activity has been found in Fes (Brickman and McIntosh, 1992) or in any other protein encoded in the ent-fes-fep gene cluster. 

Phenanthrenebiguanides possess 384) some activity against cancer. The effect of biguanides on plasma protein surface has been investigated 294, 610) with a view to the possibility of finding anti-tumor ents. Aryl-and naphthyl-biguanides exhibit 625) a slight anti-neoplastic activity in vitro in Ehrlich ascites carcinoma. 

F]-FLT is not or only marginally incorporated into DNA (<2%) and therefore not a direct measure of proliferation [122]. In vitro studies indicated that [ F]-FLT uptake is closely related to thymidine kinase 1 (TK1) activity and respective protein levels [117,118]. p F]-FLT is therefore considered to reflect TK1 activity and hence, S-phase fraction rather than DNA synthesis. Although being a poor substrate for type 1 equilibrative nucleoside transporters (ENT), cellular uptake of [ F]-FLT is further facilitated by redistribution of nucleoside transporters to the cellular membrane after inhibition of endogenous synthesis of thymidylate (TMP) de novo synthesis of TMP) [125]. However, the detailed uptake mechanism of [ F]-FLT is yet unknown and the influence of membrane transporters and various nucleoside metabolizing enzymes remains to be determined. 

AMP/intracellular mediator fm many diffo-ent hormones, communicating the signal 1 activating the cyclic AMP-dependait protein kinase... 

An increase of intracellular adenosine levels can also be achieved by inhibition of nucleoside transport proteins. Mammalian nucleoside transport processes can be classified into two types on the basis of their thermodynamic properties. These classes are the concentrative, Na+-dependent transport processes and the equilibrative, Na+-independent processes. The corresponding transporters are called CNTs (concentrative nucleoside transporters) and ENTs (equilibrative nucleoside transporters) (Pastor-Anglada and Baldwin, 2001). 

The p-dependent terminators lack the sequence of repeated A residues in the template strand but usually include a CA-rich sequence called a rut (rho rhilization) element. The p protein associates with the RNA at specific binding sites and migrates in the 5 —>3 direction until it reaches the transcription complex that is paused at a termination site. Here it contributes to release of the RNA transcript. The p protein has an ATP-depend-ent RNA-DNA helicase activity that promotes translocation of the protein along the RNA, and ATP is hydrolyzed by p protein during the termination process. The detailed mechanism by which the protein promotes the release of the RNA transcript is not known. 

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