Orange fluorescent protein

Several other fluorescent proteins have been isolated from a variety of species. We will briefly discuss the variants with the most optimal spectroscopic properties. A true orange fluorescent protein was isolated from the stony coral Fungia concinna, with good absorbance and a quantum yield of 0.45. Targeted mutagenesis was used to monomerize the protein, yielding mKO with an absorbance of 51,600 M-1 cm 1 and a quantum yield of 0.74 [84, 85], The crystal... 

Recently, evidence for large-scale associations between enzymes involved in the de novo pathway for purine synthesis has emerged. This pathway involves 10 steps that convert PRPP to inosine monophosphate. In higher eukaryotes, these steps are catalyzed by six enzymes one is trifiinctional and two are bifunctional. Versions of these enzymes tagged with green fluorescent protein (GFP) or orange fluorescent protein (OFP)... 

Solubilization of an active H,K-ATPase is also a prerequisite for reconstitution of the enzyme into liposomes. With these H,K-ATPase proteoliposomes it is then possible to study the transport characteristics of pure H,K-ATPase, without the interference of residual protein contamination that is usually present in native vesicular H,K-ATPase preparations. Rabon et al. [118] first reported the reconstitution of choleate or n-octylglucoside solubilized H,K-ATPase into phosphatidylcholine-cholesterol liposomes. The enzyme was reconstituted asymmetrically into the proteoliposomes with 70% of the pump molecules having the cytoplasmic side extravesicular. In the presence of intravesicular K, the proteoliposomes exhibited an Mg-ATP-dependent H transport, as monitored by acridine orange fluorescence quenching. Moreover, as seen with native H,K-ATPase vesicles, reconstituted H,K-... 

Bailey, S., N. Mann, C. Robinson, and D. J. Scanlan (2005). The occurrence of rapidly reversible non-photochemical quenching of chlorophyll a fluorescence in cyanobacteria. FEBS Lett 579(1) 275-280. Boulay, C., L. Abasova, C. Six, I. Vass, and D. Kirilovsky (2008a). Occurrence and function of the orange carotenoid protein in photoprotective mechanisms in various cyanobacteria. Biochim Biophys Acta 1777(10) 1344-1354. 

Kremers GJ, Hazelwood KL, Murphy CS, Davidson MW, Piston DW (2009) Photoconversion in orange and red fluorescent proteins. Nat Meth 6 355-360... 

Shaner NC, Campbell RE, Steinbach PA, Giepmans BN, Palmer AE, Tsien RY (2004) Improved monomeric red, orange and yellow fluorescent proteins derived from Discosoma sp. red fluorescent protein. Nat Biotechnol 22 1567-1572... 

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],... 

Karasawa, S., Araki, T., Nagai, T., Mizuno, H. and Miyawaki, A. (2004). Cyan-emitting and orange-emitting fluorescent proteins as a donor/accep-tor pair for fluorescence resonance energy transfer. Biochem. J. 381, 307-12. 

Purines absorb only ultraviolet light and they contribute to structural colors (white and silver) in animals. Pterines are generally yellow, orange, or red pigments. Because they are amphoteric molecules, the absorption spectra depend on the pH and present three or two absorption maxima, usually one in the visible region. Sepiapterin has an absorption maximum at 340 nm in O.IM NaOH and at 410 nm in O.IM HCl." Leucopterin has three maxima 240, 285, and 340 nm. Xanthopterin has two 255 and 391 nm. Because they are conjugated with proteins, pterins show bathochromic shifts in vivo. They also present fluorescence when excited with UV light. 

Comminution also may be used to examine the stability of dispersed phases such as oil droplets. Depending on the viscosity of the product one simply mixes it or breaks it up in a solvent (usually water but, for example, use fresh soybean oil for chocolate), a buffer or the appropriate dyes (below). For instance, we mix easily dispersible foods (cream cheese, ice cream mix or tablespreads) with dyes on slides in a ratio of about 1 1 before examination. Where the dye is a diachrome (that is, highly colored) or is fluorescent in the absence of the substrate (for example, Acridine Orange) some attempt must be made to remove excess, uncomplexed dye molecules which might confound the interpretation. This can be done by reduction of the dye concentration or by making the preparation thinner. The advantage of these simple techniques is that a battery of microchemical tests to identify protein, lipid and carbohydrate can be completed on multiple samples in a very short time period. 

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