Selectively labelled

A reaction which is of considerable importance for the selective labeling of a position adjacent to a carbonyl group is the treatment of a-halo ketones (mainly bromides) with zinc in acetic acid-OD, or deuteriobromic acid at... 

Atoms are colored according to type (see table at right). Atoms may also be labelled by selecting Labels (labels may be turned off by selecting Labels a second time). Only wire and ball-and-wire models may be labelled. 

Selective labeling of the initiator with 13C allow s substantial enhancement of the signals of the initiator residues relative to signals due to the backbone in l3C NMR spectra. Initiators labeled with or containing NMR active nuclei such as 19F or J P can also be applied. These methods are described in Section 3.5.4.2,... 

Rotational-echo double-resonance (REDOR)(75,79) is a new solid-state NMR technique which is sensitive to through-space carbon-nitrogen interactions between selectively 13C and 15N-enriched sites separated by up to 5A (20-22). The parameter directly measured in a REDOR experiment is the heteronuclear dipolar coupling constant DCN, which is in itself proportional to the inverse third power of the intemuclear distance, rCN. It is this dependence on (icn)3 which accounts both for REDOR s ability to accurately measure short distances and its insensitivity to longer-range interactions. As a technique which can probe, in detail, intermolecular interactions over a distance range of 5A, REDOR is well suited to studying the distribution of small selectively-labeled molecules in polymer delivery systems. 

Figure 5.1 Visualization of the distribution of the DA transporter, D3 receptor, and K2-opioid receptor in the human brain of a drug-free control subject and a representative cocaine overdose victim. (A, B) The DA transporter was measured using [3H]WIN 35,428 (2 nM) as described previously. (C, D) The D3 receptor was measured using [3H]-(+)-7-OH-DPAT (1 nM) in the presence of GTP (300 m/W) to enhance the selective labeling of the D3 receptor subtype over the D2 receptor subtype as described previously. (E, F) The K2-opioid receptor subtype was measured using [125l]IOXY on tissue sections pretreated with BIT and FIT to occlude binding to the p- and 8-opioid receptors, respectively.

Ni Q., Xu H., Partilla J., Costa B.D., Rice K., Rothman R. Selective labeling of K2 opioid receptors in rat brain by [125I]IOXY interactions of opioid peptides and other drugs with multiple K2a binding sites. Peptides. 14 1279, 1993. 

Razinkov, V. I., HernandezJimenez, E. I., Mikhalyov, 1.1., Cohen, F. S. and Molotkovsky, J. G. (1997). New fluorescent lysolipids Preparation and selective labeling of inner liposome leaflet. Biochim. Biophys. Acta-Biomembranes 1329, 149-158. 

Mason JR, Feong FC, Plaxco KW, et al. Two-step covalent modification of proteins. Selective labeling of Schiff base-forming sites and selective blockade of the sense of smell in vivo. J. Am. Chem. Soc. 1985 107 6075-6084. 

Kohler J.M., Csaki A., Reichert J., Moller R., Straube W., Fritzsche W., Selective labeling of oligonucleotide monolayers by metallic nanobeads for fast optical readout of DNA-chips, Sens Act B 2001 76 166-172. 

Bayer, E.A., Safars, M., and Wilchek, M. (1987b) Selective labeling of sulfhydryls and disulfides on blot transfers using avidin-biotin technology Studies on purified proteins and erythrocyte membranes. Anal. Biochem. 161, 262-271. 

Gridnev et al. showed in their study of the asymmetric hydrogenation of en-amides by Rh-catalysts another useful application of coupling constant patterns. By selectively labeling certain atoms, for example with 13C or 2D, additional couplings appear (as compared to the non-labeled product) and this will provide information about the exact structure [22]. 

Guignet EG, Hovius R, Vogel H (2004) Reversible site-selective labeling of membrane proteins in live cells. Nat Biotechnol 22 440-444... 

Lee K, Maisel K, Rouillard JM, Gulari E, Kim J (2008) Sensitive and selective label-free DNA detection by conjugated polymer-based microarrays and intercalating dye. Chem Mater 20 2848-2850... 

Fig. 4.4 Example of amino acid-type selective labeling. A [ H,15N]-HSQC spectrum obtained with the fully 15N-labeled monomeric form of the KSHV protease. B and C [nH,15N]-l-ISQC spectra...

Rotational resonance [51-53] is mostly used as a selective recoupling method between isolated spin pairs generated chemically by selective labeling. It reintroduces the homo-... 

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