4th EucheMs chemistry congress

Poster Session 1
s893
chem. Listy 106, s587–s1425 (2012)
Poster session 1 - life sciences
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SPeCtrAL AnALySiS of SeCondAry
MetABoLiteS ProduCed in funGAL
interACtionS
r. C. MenezeS 1 , C. MAtthäuS 2 , e. M. JunG 3 ,
K. KrAuSe 3 , B. dietzeK 2 , e. Kothe 3 , J. PoPP 2
1 Friedrich Schiller University, Institute of
Microbiology/Institute of Photonic Technology, Jena, Germany
2 Friedrich Schiller University, Institute of Physical
Chemistry/Institute of Photonic Technology, Jena, Germany
3 Friedrich Schiller University, Institute of Microbiology, Jena,
Germany
Fungal competition for territory and resources is inevitable
in habitats with overlap between the niches of different species or
strains. Interactions between wood-decaying basidiomycetes are
excellent examples of such competition and the outcome
determines the size of territory held by one mycelium, and hence
access to nutrients. It is a major impetus of community change,
and affects decay rates in woodland ecosystems. Competition is
brought about by antagonistic mycelial interactions which elicit
mycelial morphology, metabolic, secondary metabolite release
and extracellular enzyme pattern changes.
The basidiomycete studied, Schizophyllum commune, is a
white-rot fungus which is most widely distributed world-wide.
The abundance of S. commune can not only be attributed to its
incredible mating ability (more than 23,000 different sexes), but
also to its superior competition ability. It has been noted that
S. commune produces secondary metabolites, especially in the
interaction zone or zone of contact with competitor species. The
nature of these compounds is unknown and may be the result of
the action of the fungal oxidative enzymes in response to stress
caused in the face of a stimulans excreted from the competitor.
We attempted to elucidate the composition of the
compounds produced during these interactions using Raman
micro-spectroscopy. The principle is that Raman spectra contain
information on molecular vibrations providing a highly specific
fingerprint of the molecular structure and biochemical
composition of cells and tissues. Spectra are obtained
non-invasively without interference from water. The employment
of external labels is not necessary and the sample requires little
or no preparation. Moreover, the coupling of Raman spectroscopy
with microscopy (Raman Micro-spectroscopy) enables high
spatial resolution (below ~ 1 µm) and sensitivity. Using
particularly resonance Raman spectroscopy, we show the presence
of Indigo in the zones of interaction of the fungi.
Keywords: Raman spectroscopy; Structure elucidation;
Dyes/Pigments;
4 th EucheMs chemistry congress
P - 0 0 6 7
StruCture ChAnGe of JuveniLe horMone
BindinG Protein froM SiLKworM heMoLyMPh
M. MiyAzAwA 1 , t. yAMAzAKi 2 , r. SuzuKi 2 ,
z. fuJiMoto 2 , w. tSuChiyA 2 , M. MoMMA 2 , A. tASe 2 ,
t. ShiotSuKi 3
1 National Institute of Agrobiological Sciences, Insect Mimetics
Research Unit, Tsukuba Ibaraki, Japan
2 National Institute of Agrobiological Sciences, Biomolecular
Research Unit, Tsukuba Ibaraki, Japan
3 National Institute of Agrobiological Sciences, Insect Growth
Regulation Research Unit, Tsukuba Ibaraki, Japan
Juvenile hormones (JHs) are acyclic sequiterpenoids which
contain an unsaturated methyl ester and a terpenoid backbone with
an epoxide distal to the ester. JH regulates many processes,
including the growth, development, metamorphosis and
reproduction of insects. The JH actions are initiated by transport
of JH in the hemolymph as a complex with JH-binding protein
(JHBP) to target tissues. The concentration of JHBP in the
hemolymph varies in relation to development but almost always
exceeds the concentration of JH by some orders of magnitude. It
has been estimated that more than 99% of the JH molecules in
hemolymph are bound by JHBP. Here, we report structural
properties of JHBP based on the solution and crystal structures of
apo and JH-bound JHBP. CD measurements in buffer solution
suggested that apo-JHBP exists in equilibrium of multiple
conformations. The crystal structures of the apo and JH-bound
JHBP have an unusual fold with hydrophobic pockets. JH-binding
form results in the fully closed structure where the bound JH is
completely buried inside the protein. JH-bound JHBP opens the
gate helix to release the bound hormone likely by sensing the less
polar environment at the membrane surface. Our results reveal the
structural basis for JH transport by JHBP in hemolymph, the first
essential process of the JH signal transfer mechanisms.
Keywords: Juvenile hormone binding protein; CD
spectroscopy; X-ray crystallography;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc