LUMINESCENCE
Abstracts
The Journal o f Biological and Chemical Luminescence
Recovery was 98.5-101%. The proposed m ethod has been
applied successfully to the determ ination o f ofloxacin in tablets
and injections, and the results agree w ell w ith those obtained by
an official m ethod.
This is neccesary also in order to understand w hy so many brittle
stars g low in the dark.
Nervous control of luminescence in Ophionereis
schayeri (Ophiuroidea, Echinodermata)?
Obelin mutants with altered affinity to calcium and
bioluminescence colour
N. P. Malikova and E. S. Vysotski
P hotobiology Laboratory, Institute o f Biophysics, Russian
Academy o f Sciences, Siberian Branch, Krasnoyarsk 660036,
Russia. E-mail: npmal@yandex.ru
Since the concentration o f free calcium w ith in cell com partm ents
varies noticeably and calcium transients in those com partm ents
run in different manners, it is desirable to have calcium
indicators w hich w o uld have various sensitivities to calcium
and w hich w ould allow sim ultaneous m easurem ent o f [Ca2+] in
diffe re nt cell com partm ents. Here we report the properties of
some obelin m utants th a t sim ultaneously have the altered
biolum inescence spectra and calcium affinity. All substitutions
were done based on the 3D structures o f obelin liganddependent conform ational states. The m utants display a good
biolum inescent activity and the physiological concentration of
M g2+ has no effect on th e ir sensitivity to Ca2+. Therefore, they
hold much promise for the developm ent of dual-wavelength
methods for synchronous m onitoring o f Ca2+ transients in different
cell compartments, to reveal how the local changes in [Ca2+] switch
the exogenous and endogenous stim uli to the corresponding
cell response. Supported by: Grant No. M ac-1 963.2005.4 o f the
President o f Russian Federation; CRDF Grant No. Y4-02-05; the
Lavrenteiev Grant for Young Scientists o f the SB RAS; and RFBR
Grant No. 06-04-08076.
Distribution of luminescence in Ophiuroidea
(Echinodermata)
J. M allefet.1 F. Quevy1 and T. O'Hara T2
'M arine Biology Laboratory, Catholic University of Louvain,
3 Place Croix du Sud, B-1348 Louvain-la-Neuve, Belgium.
E-mail: Jerome.mallefet@ uclouvain.be
2Museum Victoria, GPO Box 666, M elbourne 3001, Australia
A lth o u g h b io lu m in e s c e n c e is w e ll k n o w n in E ch in o d e rm s,
it is still poorly understood in term s o f phylogenetic and
biogeographic distribu tion. This amazing capability has been
m ostly studied in the O phiuroidea over the last 15 years, b u t on
a lim ited num ber o f species. Recently, a com parative study on
brittle sta r luminescence was initiated and analyses were
conducted after a large sam pling effort. The results indicated
that, o u t o f 195 species, the total num ber o f known lum inous
species increased from 33 in 1995 to 64 in 2007. They were
m ainly collected on hard substrata in deep water, where
luminescence appeared more intense. A ltho ug h brittlestar
luminescence was observed in tropical and tem perate waters
from shallow to abyssal depths, it was least prelevant on tropical
coral reefs. Analysis is in progress to try to h ig h lig h t a possible
link between luminescence and ophiuroid phylogeny. New field
surveys in a variety o f m arine regions and habitats w ill be
organized to increase the num ber o f ophiuroid species tested.
www.interscience.wiley.com /journal/bio
J. M allefet.1 J. Renard J1 and T. O'Hara2
'M arine Biology Laboratory, Catholic University o f Louvain,
3 Place Croix du Sud, B-1348 Louvain-la-Neuve, Belgium.
E-mail: Jerome.mallefet@ uclouvain.be
"Museum Victoria, GPO Box 666, M elbourne 3001, Australia
Am ong echinoderm s, luminescence control mechanisms have
been m ainly studied in the class O phiuroidea. Initial research
perform ed on Am phipholis squamata and Am phiura filiform is
suggested the preponderance o f cholinergic control mechanisms.
W ithin the fram ew ork o f a com parative study of ophiuroid
luminescence, a research program m e was developed on
Ophionereis schayeri, a com m on southern Australian lum inous
b rittle star. Results show th a t ^a m in o b u ty ric acid (GABA) is the
main neurotransm itter involved in lig h t emission. GABA triggers
lig h t emission throu gh the activation o f the GABAb receptor's
sub-type located on the m em brane of the lum inous cells.
Nevertheless, acetylcholine induced a weaker luminescence,
probably via muscarinic cholinergic receptors. Furthermore, GABA,
besides occupying the role of main neurotransm itter, seems to
act as a positive neurom odulator o f the cholinergic response. The
results of this research reinforce the idea that many neurotransmitters
and neurom odulators are involved in the control o f ophiuroid
luminescence.
The function of conserved cystein residues in the
bioluminescence of coelenterazine-dependent
luciferase from Metridia longa; testing with sitedirected mutagenesis
S. V. M arkova. G. A. Stepanyuk and E. S. Vysotski
P hotobiology Laboratory, Institute o f Biophysics SB RAS,
Krasnoyarsk 660036, Russia. E-mail: svetlana@ibp.ru
Recently, several secreted luciferases from the copepod Metridia
longa (MLuc) were cloned and one o f them was successfully
used as a bio lu m in e sce n t re p o rte r enzym e in m am m alian
cells. MLuc is a small Cys-rich protein, w hich m ost likely holds
in tra m o le c u la r d isu lp h id e bonds. Here we re p o rt th e results
o f m utational analysis o f conserved 10 Cys residues o f MLuc,
w hich were revealed from the protein alignm ent. All cysteines
are fo u n d w ith in tw o no n -id e n tica l 31 am in o acid repeats
(five in each). To estim ate the role o f these Cys residues in
biolum inescence, each one was substituted by both Ala and
Ser using site-directed mutagenesis. Practically all m utations
sh ift th e tem p e ra tu re o p tim u m o f M Luc biolum inescence to
0-4°C and result in decreasing biolum inescent activity to a
variable degree. However, the replacements o f the last Cys
residues in the repeats led to alm ost com plete loss o f MLuc
biolum inescent activity. This suggests the crucial role o f these
tw o Cys residues for enzyme catalytic activity. The possible
fun ction o f cysteines in m aintaining structural stability is
discussed. Supported by RFBR Grant No. 05-04-48271 and RFBRTaiwan NSC Grant No. 89502.
Copyright © 2008 John W iley & Sons, Ltd.
Luminescence 2008; 2 3 :5 9 -1 1 4