Photoaffmity labelling

Singh AK. 1993. Effects of chronic low-level lead exposure on mRNA expression, ADP-ribosylation and photoaffmity labelling with [ -32P]guanine triphosphate -y -azidoanilide of GTP-binding proteins in neurons isolated from the brain of neonatal and adult rats. Biochem Pharmacol 45 1107-1114. 

Nakayama H, Taki M, Striessnig J, Glossmann H, Catterall WA, Kanaoka Y. (1991) Identification of 1,4-dihydropyridine binding regions within the alpha 1 subunit of skeletal muscle Ca channels by photoaffmity labeling with diazipine. Proc Natl Acad Sci USA 88 9203-9207. 

Wang X, Narasimhan TR, Morrison V, et al. 1991. In situ and in vitro photoaffmity labeling of the nuclear aryl hydrocarbon receptor from transformed rodent and human cell lines. Arch Biochem Biophys 287 186-194. 

Prestwich G. D., Golec F. A. and Andersen N. H. (1984) Synthesis of a highly tritiated photoaffmity labeled pheromone analog for the moth Antheraea polyphemus. J. Labelled Cmpnd. Radiopharm. 21, 593-601. 

Cyclophilin D is a mitochondrial matrix protein whose role in mitochondrial permeability transition is well characterized.57 100 101 Mitochondria in the heart, liver, and brain form large pores in response to oxidative stress and elevated Ca+2 levels. These pores are blocked by CsA. Studies with photoaffmity labeled CsA derivatives identified CyPD as a likely mediator of the pore blockade by CsA.102... 

One remarkable feature of the nonnucleoside RT inhibitors when compared to their nucleoside counterparts is the selectivity they exhibit for HIV-1 RT compared to HIV-2 RT. They are typically inactive against HIV-2 RT whereas nucleoside inhibitors (as their triphosphates) are usually equally effective against both enzymes. Efforts to understand this phenomenon involved biophysical and structural studies to identify the binding site occupied by NNRTIs. Biochemical studies showed that the NNRTIs are noncompetitive inhibitors of RT, thus indicating that they do not compete with substrates at the enzyme active site. Photoaffmity labeling experiments identified two tyrosine residues, namely tyrosines 181 and 188 as components of the NNRTI binding site. In sequence, these tyrosine residues are close to aspartic acid residues 185 and 186, which constitute part of the enzyme active site. Subsequently, cocrystal X-ray pictures of RT with nevirapine (Figure 19.29) and with other inhibitors provided a more detailed structural perspective on the interactions of the NNRTIs and RT. 

Sasaki, T., Shimazawa, R., Sawada, T, Iijima, T, Fukasawa, H, Shudo, K, Hashimoto, Y., and Iwasaki, S (1995) Determination of the photoaffmity-labeled site on the ligand-binding domain of retinoic acid receptor a Biochem Biophys Res. Comm. 207, 444-451... 

H.Y. Yoon, E.Y. Lee, S.W. Cho, Cassette mutagenesis and photoaffmity labeling of adenine binding domain of ADP regulatory site within human glutamate dehydrogenase. Biochemistry, 2002, 41, 6817-6823. 

J.P. Whitelegge, P. Jewess, M.G. Pickering, C. Gerrish, P. Camilleri, J.R. Bowyer, Sequence-analysis of photoaffmity-labeled peptides derived by proteolysis of photosystem-2 reaction centers from thylakoid membranes treated with [C-14] azidoatrazine, Eur. J. Biochem., 1992,207, 1077-1084. 

Sorba, G. Tertuik, W. Ganellin, C. R. Synthesis and authentication of iodoazidophenpyr-amine, a photoaffmity reporter ligand previously used for histamine Hj-receptor labelling. Arch. Pharm. (Weinheim) 1995, 328, 677-680. 

Discodermolide (DDM, Fig. 16) is a marine natural product that promotes MT assembly more potently than PTX and is active against some PTX-resistant cell lines [118-120], The photoaffmity analogue C19-BPC-DDM labels (3-tubulin in close proximity to the taxol binding site [121] and DDM itself is a competitive inhibitor of PTX binding to MT [120], suggesting that DDM also binds to the PTX binding site on P-tubulin. 

Trommer, W.E. and Vogel, P.D.. (1992) Photoaffmity spin labeling, in Zhdanov, R.I. (eds.), Bioactive Spin Labels, Springer-Verlag, Heidelberg, pp. 405-427. 

The 4 -carbonyl group is a good site for tethering fiinctional groups as a photoafFmity group, since most ABA derivatives modified at C-4 exhibit moderate biological activities. Kohler et al synthesized [ I]-labeled ABA that tethered an aromatic hydrazide at C-4 (3) as the first radio-iodinated ABA photoafifmity probe [24]. This compound, was about one-tenth as active as ABA in the inhibition of GA-induced a-... 

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