CIDs chemical inducers

Examples of small molecules, altered cell culture conditions, proteins, and genetic constructs used to probe RME. CID chemical inducer of dimerization. 

PCI, positive chemical ionisation El, electron impact CID, collisionally induced dissociation. 

Fig. 7.12. Structures of several of the small molecules used as Chemical Inducers of Dimerizations (CIDs) in the three-hybrid systems to date.

Chemical inducers of dimerization (CID) are bivalent small molecules that bind t vo proteins simultaneously. The purpose of these molecules is to bring the proteins together to induce signal transduction [27]. For brevity, we will limit our discussion to CIDs that directly control transcription. The basic architecture of these systems consists of two chimeric proteins. The first contains a DNA-binding domain (DBD) fused to a ligand-binding domain (LBD) and the second chimera contains an LBD and an activation domain (AD). The small molecule that binds both of these proteins simultaneously induces proximity of the two proteins, resulting in transcription activation (Fig. 8.11). 

Fig.8.n Chemical inducers of dimerization (CID) to control transcription. This system requires two chimeric proteins, one comprising a DNA-binding domain (DBD) fused to a ligand-binding domain (LBD), and the other comprising an LBD fused to a transcriptional... 

Just as a dimeric RNA molecule can be introduced to mediate the interaction between the DNA-binding and ADs, so can a dimeric small molecule [17]. In fact, well before their use in a small molecule three-hybrid assay, dimeric small molecules were used as chemical inducers of dimerization (CIDs) to artificially oligomerize fusion proteins in vivo [18]. In the yeast three-hybrid system, the union of two protein fusions and a CID reconstitute the transcription of a reporter gene (Fig. 4.1-3(d)). In 1996, Licitra and Liu built what they called a yeast three-hybrid assay [19]. This assay consists of two fusion proteins and a heterodimeric small molecule CID that brings these fusion proteins together to activate the transcription of a reporter gene (Fig. 4.1-3 d)). 

GC, gas chromatography El, electronic impact PI, positive-ion mode LC, liquid chromatography ESI, electrospray ionization CID, collision-induced dissociation Q, quadrupole SIM, selected ion monitoring NI, negative-ion mode APCI, atmospheric pressure chemical ionization SRM, selected reaction monitoring Q-TOF, quadrupole-time-of-flight... 

CHCA a-cyano-4-hydroxycinnamic acid ChEBI Chemical Entities of Biological Interest CID collision-induced dissociation CL cardiolipin... 

D, two-dimensional quadmpole field 3D, three-dimensional quadrupole field APCl, atmospheric pressure chemical ionization APPI, atmospheric-pressure photoionization ESI, electrospray ionization MALDI, matrix-assisted laser desorption ionization CID, collision-induced dissociation ETD, electron transfer dissociation. 

The use of collision-induced dissociation (CID) and MS/MS techniques in conjunction with the API interfaces has dramatically impacted the fleld of environmental analysis. These techniques are now preferred for the determination of triazine compounds in water, soil, crops, etc., owing to the significant improvements in selectivity obtained via the monitoring of precursor-product ion pairs and increased sensitivity due to the reduction of chemical noise. 

DGE a AC AMS APCI API AP-MALDI APPI ASAP BIRD c CAD CE CF CF-FAB Cl CID cw CZE Da DAPCI DART DC DE DESI DIOS DTIMS EC ECD El ELDI EM ESI ETD eV f FAB FAIMS FD FI FT FTICR two-dimensional gel electrophoresis atto, 10 18 alternating current accelerator mass spectrometry atmospheric pressure chemical ionization atmospheric pressure ionization atmospheric pressure matrix-assisted laser desorption/ionization atmospheric pressure photoionization atmospheric-pressure solids analysis probe blackbody infrared radiative dissociation centi, 10-2 collision-activated dissociation capillary electrophoresis continuous flow continuous flow fast atom bombardment chemical ionization collision-induced dissociation continuous wave capillary zone electrophoresis dalton desorption atmospheric pressure chemical ionization direct analysis in real time direct current delayed extraction desorption electrospray ionization desorption/ionization on silicon drift tube ion mobility spectrometry electrochromatography electron capture dissociation electron ionization electrospray-assisted laser desorption/ionization electron multiplier electrospray ionization electron transfer dissociation electron volt femto, 1CT15 fast atom bombardment field asymmetric waveform ion mobility spectrometry field desorption field ionization Fourier transform Fourier transform ion cyclotron resonance... 

For MS work, the electron impact (El) mode with automatic gain control (AGC) was used. The electron multiplier voltage for MS/MS was 1450 V, AGC target was 10,000 counts, and filament emission current was 60 pA with the axial modulation amplitude at 4.0 V. The ion trap was held at 200°C and the transfer line at 250°C. The manifold temperature was set at 60°C and the mass spectral scan time across 50-450 m/z was 1.0 s (using 3 microscans). Nonresonant, collision-induced dissociation (CID) was used for MS/MS. The associated parameters for this method were optimized for each individual compound (Table 7.3). The method was divided into ten acquisition time segments so that different ion preparation files could be used to optimize the conditions for the TMS derivatives of the chemically distinct internal standard, phenolic acids, and DIMBOA. Standard samples of both p-coumaric and ferulic acids consisted of trans and cis isomers so that four segments were required to characterize these two acids. The first time segment was a 9 min solvent delay used to protect the electron multiplier from the solvent peak. 

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