Chromoprotein

Chromoproteins. Compounds of proteins with haem or some similar pigments. 

The tightly bound chromophore could be extracted from the protein with methanol [186], and the major component of the extract was determined to have the enediyne structure 116 (Figure 11.21), related to chromophores of other chromoprotein antitumor agents such as neocarzinostatin. Additional minor components were extracted, variously containing an OH group instead of OMe attached to the enediyne core, with Cl instead of OMe when chloride was present in the buffer salt, or with OEt instead of OMe when ethanol was used for the extraction. Another byproduct was isolated in the form of structure 117, consistent with a facile cy-doaromatization reaction as observed for all other enediyne antibiotics. Surprisingly, 117 also displayed antibiotic and antitumor activity, perhaps due to alkylation of DNA or protein by the aziridine. The interpretation of these results was that 116 and the other enediyne byproducts were merely artifacts of the extraction procedure and that the true structure of the maduropeptin chromophore is the aziridine 118. 

Lipoproteins. The lipid moiety of the lipoproteins is quite variable, both qualitatively and quantitatively Mucoproteins are carbohydrate in nature Chromoproteins are pigments... 

The unicity of the GFP family is better appreciated when knowing that all red GFPs mature from a green precursor carrying the same chromophore as AvGFP, to which they can eventually revert back [33, 41], while initially green GFPs can evolve in different ways toward red emission [20, 42-44], Similarly, many chromoproteins can be turned fluorescent at alkaline pHs [45], upon photoactivation [46], or... 

First of all, most natively bright green or red GFPs crystallize with a nearly coplanar cis chromophore conformation, while all nonfluorescent chromoproteins seem to bear a trans and noncoplanar chromophore [38, 49]. For AvGFP, there is, up to now, no indication of a chromophore conformation different from the cis isomer. However, various other situations have been reported in the GFP family,... 

Shkrob MA, Mishin AS, Chudakov DM, Labas YA, Lukyanov KA (2008) Chromoproteins of the green fluorescent protein family Properties and applications. Russ J Bioorg Chem 34 517-525... 

Gurskaya NG, Fradkov AF, Terskikh A, Matz MV, Labas YA, Martynov VI, Yanushevich YG, Lukyanov KA, Lukyanov SA (2001) GFP-like chromoproteins as a source of far-red fluorescent proteins. FEBS Lett 507 16-20... 

Battad JM, Wilmann PG, Olsen S, Byres E, Smith SC, Dove SG, Turcic KN, Devenish RJ, Rossjohn J, Prescott M (2007) A structural basis for the pH-dependent increase in fluorescence efficiency of chromoproteins. J Mol Biol 368 998-1010... 

Verkhusha W, Chudakov DM, Gurskaya NG, Lukyanov S, Lukyanov KA (2004) Common pathway for the red chromophore formation in fluorescent proteins and chromoproteins. Chem Biol 11 845-854... 

Total synthesis of phytochromobilin starting from 2-tosylpyrroles, which are prepared by (3-nitro acetates with TosMIC (Scheme 10.4) has been reported.28 Phytochrome is a chromoprotein concerned in a variety of processes in higher plants such as growth, development, and morphogenesis, 29... 

The isolation of fluorescent proteins from nonbioluminescent species has led to the discovery of a super family of GFP-like proteins [1, 14]. Recently, six additional GFP-like proteins were isolated from A. victoria-related jellyfish [14-16]. Furthermore, a large number of GFP-like proteins have been isolated from Anthozoa species, ranging in fluorescence from green to orange-red, as well as nonflu-orescent purple-blue chromoproteins [17-19],... 

Ganesan, S., Ameer-Beg, S. M., Ng, T. T., Vojnovic, B. and Wouters, F. S. (2006). A dark yellow fluorescent protein (YFP)-based Resonance Energy-Accepting Chromoprotein (REACh) for Forster resonance energy transfer with GFP. Proc. Natl. Acad. Sci. USA 103, 4089-94. 

The cell illustrated opposite, a rod, has a structure divided by membrane discs into which the 7-helix receptor rhodopsin is integrated (see p. 224). In contrast to other receptors in the 7-helix class (see p. 384), rhodopsin is a light-sensitive chromoprotein. Its protein part, opsin, contains the aldehyde retinal (see p. 364)—an isoprenoid which is bound to the e-amino group of a lysine residue as an aldimine. 

Kedarcidin is a chromoprotein anti-tumor antibiotic, produced by an actinomycete strain. It is an acidic complex with an apparent molecular weight of 12,400 Da, and it consists of an apoprotein and a cytotoxic highly unstable nonprotein chromophore 12 that possesses a conformationally defined ansamacrocyclic bridge. Retrosynthetically,... 

Proteins with molecular weights in the millions are the major constituents of all living cells. Simple proteins are hydrolyzed only to amino acids. Coqjugated proteins are hydrolyzed to amino acids and nonpeptide substances known as prosthetic groups. These prosthetic groups include nucleic acids of nucieoproteins, carbohydrates of glycoproteins, pigments (such as hemin and chiorophyli) of chromoproteins, and fats or lipids of lipoproteins. 

Red-cell (dark adapted) Blepharisma japonicum were cultured in Pisa, in the dark, at 23 °C, in the presence of the Enterobacter aerogenes bacterium as food supply [7]. Blue-cell (light adapted) Blepharisma japonicum were produced by in vivo photoconversion of blepharismin into oxyblepharismin under a low intensity cold white lamp (below 10 W/m2). Blue cells were washed, collected by low speed centrifugation and resuspended in a 20-mM sodium cholate solution. The chromoprotein was obtained by FPLC chromatography of this preparation, on a hydroxyapatite column. The applied eluent was a phosphate buffer (pH 7.4), first 0.05 M and then 0.2 M. This ionic strength step affects the affinity of the biomolecules with the hydroxyapatite [8]. 

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