Luminescence of the

It should be noted that Cypridina luciferin emits a fairly strong chemiluminescence in aqueous solutions in the presence of various lipids and surfactants, even in the complete absence of luciferase. The luminescence is especially conspicuous with cationic surfactants (such as hexadecyltrimethylammonium bromide) and certain emulsion materials (such as egg yolk and mayonnaise). Certain metal ions (especially Fe2+) and peroxides can also cause luminescence of the luciferin. Therefore, great care must be taken in the detection of Cypridina luciferase in biological samples with Cypridina luciferin. 

Heat stability The Oplophorus luminescence system is more thermostable than several other known bioluminescence systems the most stable system presently known is that of Periphylla (Section 4.5). The luminescence of the Oplophorus system is optimum at about 40°C in reference to light intensity (Fig. 3.3.3 Shimomura et al., 1978). The quantum yield of coelenterazine is nearly constant from 0°C to 20°C, decreasing slightly while the temperature is increased up to 50°C (Fig. 3.3.3) at temperatures above 50°C, the inactivation of luciferase becomes too rapid to obtain reliable data of quantum yield. In contrast, in the bioluminescence systems of Cypridina, Latia, Chaetopterus, luminous bacteria and aequorin, the relative quantum yields decrease steeply when the temperature is raised, and become almost zero at a temperature near 40-50°C (Shimomura et al., 1978). 

Concerning the Ca2+-triggered luminescence of obelin, Deng et al. (2001) reported an interesting observation (Fig. 4.2.2) the luminescence of the recombinant obelin from O. longissima is blue (7max 475 nm), whereas a mutant of this obelin, in which the amino acid residue-92 has been changed from tryptophan to phenylalanine, emits... 

Fig. 4.8.2 Comparison of the in vivo and in vitro luminescence of the photoproteins of Mnemiopsis sp. and Beroe ovata (A) in vitro luminescence spectra of mineopsin-1, -2, and berovin (B) in vivo luminescence spectrum of Mnemiopsis, (C) in vivo luminescence spectrum of Beroe. From Ward and Seliger, 1974b, with permission from the American Chemical Society.

Fig. 6.3.3 Relationship between pH and the initial light intensity in the ATP-stimulated luminescence of the homogenate of Watasenia arm light organs in the presence of 1.5 mM ATP and 0.3 mM MgCl2 (Tsuji, 1985).

Fig. 6.3.7 Luminescence spectrum of a homogenate of the luminous organ of Symplectoteuthis oualaniensis in the presence of 0.5 M KC1 (from Tsuji and Leisman, 1981). A homogenate suspension (1 ml) and 1MKC1 (1 ml), both made with 50 mM Tris-HCl, pH 7.6, containing 1 mM dithioerythritol, were mixed and the spectrum was measured 6 min after mixing. Note that the luminescence of the photoprotein symplectin isolated from the luminous organs showed a maximum at 470—480 nm (Takahashi and Isobe, 1993, 1994).

The luminescence reaction of symplectin induced by warming is slow and not sufficiently bright to account for the bright luminescence of the live squid. The factors and conditions that cause the intense in vivo luminescence remain to be identified. 

In vivo luminescence of the Symplectoteutbis species. The live specimens of both S. oualaniensis and S. luminosa emit bright flashes... 

Properties of activated products. The luminescence of the activation products of panal is elicited by Fe2+ and H2O2, and the light emission is significantly enhanced by the presence of various detergents, particularly cationic detergents, such as CTAB. The influence... 

Davenport et al. (1952) were unsuccessful in their attempts to restore the luminescence of the filtered aqueous extract of Luminodesmus. Hastings and Davenport (1957) saw a weak luminescence in their filtered aqueous extracts made from the acetone powder of the millipedes. They found that the luminescence is dependent on pH, with an optimum at about pH 8.9, and that the light intensity could be increased by 10-30% by adding ATP. Hastings and Davenport also measured the luminescence spectrum of live animals, finding an emission peak at 495 nm. 

Fig. 10.3.1 Bioluminescence spectrum of the centipede Orphaneus brevilabiatus (left panel), and the influence of pH on the luminescence of the exudate of the same centipede in 0.1 M potassium citrate/phosphate buffers (right panel). From Anderson, 1980, with permission from the American Society for Photobiology.

Shimomura, O., and Johnson, F. H. (1976). Calcium-triggered luminescence of the photoprotein aequorin. Symp. Soc. Exp. Biol. 30 41-54. 

Vysotski, E. S., Bondar, V. S., Trofimov, K. P., and Gitelzon, I. I. (1991). Luminescence of the calcium-activated photoprotein obelin under the action of active forms of oxygen. Dokl. Akad. Nauk SSSR 321 850-854. 

In both cases, the luminescence of the species A is quenched, but in the case of energy transfer the luminescence of species A is replaced by the luminescence of species B (sensitization process). 

A supramolecular assembly of macromolecules bearing antenna dendron has been reported. Pyrazole-anchored PBE dendrons were synthesized to examine the coordination behavior to transition-metal cations (Cu, Au, Ag) [31]. Self-assembled metallacycles were found. The Cu-metallacycle further formed luminescent fibers about 1 pm in diameter. The luminescence (605 nm) occurred by the excitation of the dendron (280 nm) and the excitation spectrum was coincident with the absorption spectrum of the dendron, suggesting the antenna effect. Interestingly, the luminescence of the Cu-metallacycle fiber disappeared when the fiber was dissociated into the individual metallacycles in C2H2. 

Having investigated the electrochemical behavior of ZnSe, and in view of the well-known blue luminescence of the compound, the previous authors extended their work to study electroluminescence from I-doped n-ZnSe crystals under anodic polarization in aqueous media containing metal ions such as Cu(II) and Sn(II) [123]. 

Kohler, et al. (2000) in Germany compared the egg yolk luminosity and plumage condition of hens either reared indoors or at pasture. They found that intensive elements such as indoor cages and behavioural disorders led to low luminescence of the yolk, whereas fresh grass, exercise and space lead to a high luminescence of the yolk, which is correlated with intact plumage. 

Energy transfer entails the excitation of a molecule that during the lifetime of the excited state passes its excitation energy to another molecule. The loss of excitation energy from the initial excited species (the donor) results in quenching of the luminescence of the energy donor and may result in luminescence from the energy recipient (acceptor), which becomes excited in the process. 

Trivalent lanthanide cations have luminescent properties which are used in a number of applications. The luminescence of the lanthanide ions is unique in that it is long-lasting (up to more than a millisecond) and consists of very sharp bands. Lanthanide emission, in contrast to other long-lived emission processes, is not particularly sensitive to quenching by oxygen because the 4f electrons found within the inner electron core... 

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