Chemical probes function

NMR methods can be applied to give quantitative determination of initiator-derived and other end groups and provide a wealth of information on the polymerization process. They provide a chemical probe of the detailed initiation mechanism and a greater understanding of polymer properties. The main advantage of NMR methods over alternative techniques for initiator residue detection is that NMR signals (in particular nC NMR) are extremely sensitive to the structural environment of the initiator residue. This means that functionality formed by tail addition, head addition, transfer to initiator or primary radical termination, and various initiator-derived byproducts can be distinguished. 

O Hare, H. M., Johnsson, K. and Gautier, A. (2007). Chemical probes shed light on protein function. Curr. Opin. Struct. Biol. 17, 488-94. 

Figure 16 (a) Structures of adenylation domain intermediates and inhibitors aminoacyl-sulfamoyl adenosine (AMS) and cisoid -like macrocyclic inhibitor, (b) Alkyne-functionalized chemical probe for NRPS A and PCP domains, (c) Structure of aminoacyl PCP, SNAC substrate analogue, and hydrolytically stable phosphopantetheinyl analogue, (d) Structure of vinylsulfonamide probe. R represents a peptide component and R an amino acid side chain. 

Comyn [1] has pointed out that maximum bond strength and consequently greater adhesion between the substrate and polymer could be achieved with a monolayer of silane bound to both the adherend and adhesive. The current investigation was undertaken to evaluate the possibility of monolayer level depositions on silicon substrates by employing a few w -functionalized alkanoyl-substituted derivatives of APTES which will provide polar moieties as well. The interactions of these functionalized silanes covalently immobilized on silicon with octadecylamine and octadecanoic acid, used as models for basic and acidic polymeric adhesives, were also examined in this study. Characterization of the silanized surfaces as well as studies on their interactions with the above two chemical probes were carried out through ellipsometric and XPS measurements. 

Volume 468. Biophysical, Chemical, and Functional Probes of RNA Structure, Interactions and Folding Part A Edited by Daniel Herschlag... 

Yoshida, M., Horinouchi, S., and Beppu, T. (1995) Trichostatin A and trapoxin Novel chemical probes for the role of histone acetylation in chromatin structure and function. Bioessays 17, 423-430. 

Site-directed mutagenesis can be used to establish the function of individual amino acid residues. This method also allows to introduce chemical probes (e.g., fluorophores) that may give insight into the dynamic features and folding properties of a flavoenzyme and its interaction with other protein partners (33, 34). In this context, it is important to stress that catalytically relevant conformational changes of flavoenzymes have been demonstrated that actually exploit the flavin itself as an excellent intrinsic spectroscopic probe (18, 31). 

Recent achievements in the development of active-site directed affinity probes for proteases and other enzyme classes provide direct chemical labeling of proteases of interest in the biological system (24-27). These specific activity probes allow joint evaluation of selective protease inhibition concomitant with labeling of relevant protease enzymes for more analyses. Moreover, activity-based probes that selectively label the main protease subclasses—cysteine, serine, metallo, aspartic, and threonine—can provide advantageous chemical approaches for functional protease identification. Activity probe labeling of proteases allows direct identihcation of enzyme proteins by tandem mass spectrometry. Such chemical probes directed to cysteine proteases have been instrumental for identification of the new cathepsin L cysteine protease pathway for neuropeptide biosynthesis, as summarized in this article. 

Glycome Glycomics Glycoproteomics Functional glycomics Microarray Mass spectrometry Chemical probe Molecular imaging Bioinformatics... 

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