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<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center"
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style="FONT-SIZE: 16pt; FONT-FAMILY: Arial; mso-bidi-font-family: 'Times New Roman'; mso-bidi-font-size: 18.0pt">Seminarios
INQUIMAE-DQIAQF<?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" /><o:p></o:p></SPAN></U></B></P>
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<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt 99pt" align=center><B
style="mso-bidi-font-weight: normal"><SPAN
style="FONT-SIZE: 18pt; FONT-FAMILY: Arial; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: ES-TRAD">Miércoles
2 de Diciembre 13 hs.<o:p></o:p></SPAN></B></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt 99pt" align=center><SPAN lang=ES
style="FONT-FAMILY: Arial; mso-bidi-font-family: 'Times New Roman'; mso-bidi-font-weight: bold"><FONT
size=4>Aula Seminarios INQUIMAE-DQIAQF<o:p></o:p></FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt 99pt" align=center><SPAN lang=ES
style="FONT-FAMILY: Arial; mso-bidi-font-family: 'Times New Roman'; mso-bidi-font-weight: bold"><FONT
size=4>Ciudad Universitaria Pab. II 3° Piso<o:p></o:p></FONT></SPAN></P>
<H1 style="MARGIN: 12pt 0cm 3pt; TEXT-ALIGN: center" align=center><FONT
size=4><I style="mso-bidi-font-style: normal"><SPAN lang=EN-US
style="FONT-WEIGHT: normal; FONT-FAMILY: 'Arial Black'; mso-ansi-language: EN-US">Professor
Gerhard Schenk</SPAN></I><I style="mso-bidi-font-style: normal"><SPAN lang=ES
style="FONT-WEIGHT: normal; FONT-FAMILY: 'Arial Black'; mso-bidi-font-weight: bold"><o:p></o:p></SPAN></I></FONT></H1>
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style="COLOR: black; mso-ansi-language: EN-US"><o:p><FONT face="Arial Black"
size=4></FONT></o:p></SPAN></B></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center"
align=center><?xml:namespace prefix = st1 ns =
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lang=EN-US
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-US; mso-bidi-font-weight: bold">School</SPAN></st1:PlaceType><SPAN
lang=EN-US
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-US; mso-bidi-font-weight: bold">
of <st1:PlaceName w:st="on">Chemistry</st1:PlaceName> and Molecular Biosciences,
The <st1:PlaceType w:st="on">University</st1:PlaceType> of <st1:PlaceName
w:st="on">Queensland</st1:PlaceName>, <st1:country-region w:st="on">St.
Lucia</st1:country-region>, Qld 4072, <st1:country-region w:st="on"><st1:place
w:st="on">Australia</st1:place></st1:country-region><o:p></o:p></SPAN></P>
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align=center><B style="mso-bidi-font-weight: normal"><SPAN lang=EN-US
style="COLOR: black; mso-ansi-language: EN-US"><o:p><FONT
face="Bookman Old Style" size=5> </FONT></o:p></SPAN></B></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center"
align=center><B style="mso-bidi-font-weight: normal"><SPAN lang=EN-US
style="COLOR: black; mso-ansi-language: EN-US"><o:p><FONT
face="Bookman Old Style" size=5></FONT></o:p></SPAN></B></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center"
align=center><FONT size=4><FONT face="Bookman Old Style"><B
style="mso-bidi-font-weight: normal"><SPAN lang=EN-US
style="COLOR: black; mso-ansi-language: EN-US">GpdQ, an Enzymatic Bioremediator
with an Interesting Mechanism of Action</SPAN></B><B><SPAN lang=EN-US
style="mso-ansi-language: EN-US"><o:p></o:p></SPAN></B></FONT></FONT></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: justify"
align=center><SPAN lang=EN-US
style="mso-ansi-language: EN-US; mso-bidi-font-weight: bold"><o:p><FONT
face="Bookman Old Style" size=4></FONT></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: justify"
align=center><SPAN lang=EN-US
style="mso-ansi-language: EN-US; mso-bidi-font-weight: bold"><FONT
face="Bookman Old Style" size=4><SPAN
style="mso-spacerun: yes"></SPAN></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: justify"
align=center><SPAN lang=EN-US
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-US; mso-bidi-font-weight: bold">The
glycerophosphodiesterase (GpdQ) from <I>Enterobacter aerogenes</I> is a
promiscuous binuclear metallohydrolase that catalyzes the hydrolysis of mono-,
di- and triester substrates, including some organophosphate pesticides and
products of the degradation of nerve agents.<SPAN
style="mso-spacerun: yes"> </SPAN>GpdQ has attracted recent attention as a
promising enzymatic bioremediator.<SPAN style="mso-spacerun: yes">
</SPAN>In the absence of substrates the enzyme exists predominantly in a
catalytically inactive mononuclear state.<SPAN style="mso-spacerun: yes">
</SPAN>The addition of substrate increases the affinity of the second metal
binding site (</SPAN><SPAN lang=EN-US
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-US">the
â site<SPAN style="mso-bidi-font-weight: bold">), leading to the formation of an
active binuclear catalyst.<SPAN style="mso-spacerun: yes">
</SPAN></SPAN>Stopped-flow fluorescence measurements identified three distinct
phases in the catalytic turnover, associated with the (i) initial binding of
substrate to the active site, (ii) the assembly of a catalytically active
binuclear centre, and (iii) subsequent slower structural rearrangements to
optimize catalysis. Furthermore, the hydrogen bond network that connects the
substrate binding pocket with the two metal ions plays an important role in
modulating both the coordination of the â metal ion and the mechanism of
catalysis.<SPAN style="mso-spacerun: yes"> </SPAN>The latter is associated
with the flexible coordination of one of the ligands to the weaker bound â metal
ion (Asn80).<SPAN style="mso-spacerun: yes"> </SPAN>Overall, <SPAN
style="mso-bidi-font-weight: bold">GpdQ employs an intricate regulatory
mechanism for catalysis, </SPAN>a paradigm of a substrate- and metal ion-induced
fit to optimize catalysis.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: justify"
align=center><SPAN lang=ES
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'"><o:p> </o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: justify"
align=center><SPAN lang=ES
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'"><o:p><FONT size=2><FONT
face=Arial> <FONT size=1>References:</FONT></FONT></FONT></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: justify"
align=center><SPAN lang=ES
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'"><o:p>
<TABLE class=MsoNormalTable
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<TR style="mso-yfti-irow: 0; mso-yfti-firstrow: yes">
<TD
style="BORDER-RIGHT: #ece9d8; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 431.9pt; PADDING-TOP: 0cm; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent"
vAlign=top width=576>
<P class=MsoNormal
style="MARGIN: 0cm 4.3pt 6pt 0cm; TEXT-ALIGN: justify; tab-stops: 9.0pt 22.5pt 45.0pt 72.0pt 108.0pt 153.0pt 162.0pt right lined 241.0pt left blank 9.0cm 297.7pt"><SPAN
lang=EN-US
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-US">Hadler
K.S., Gahan L.R., Ollis D.L. and Schenk G. (<B
style="mso-bidi-font-weight: normal">2009</B>) The bioremediator
glycerophosphodiesterase employs a non-processive mechanism for
hydrolysis. <I style="mso-bidi-font-style: normal">J. Inorg. Biochem.</I>
(in press)<SPAN style="COLOR: black">.</SPAN><o:p></o:p></SPAN></P>
<P class=MsoNormal
style="MARGIN: 0cm 4.3pt 6pt 0cm; TEXT-ALIGN: justify; tab-stops: 9.0pt 22.5pt 45.0pt 72.0pt 108.0pt 153.0pt 162.0pt right lined 241.0pt left blank 9.0cm 297.7pt"><SPAN
lang=EN-US
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-US">Hadler
K.S., Mitić N., Ely F., Hanson G.R., Gahan L.R., Larrabee J.A., Ollis D.L.
and Schenk G. (<B style="mso-bidi-font-weight: normal">2009</B>)
Structural flexibility enhances the reactivity of the bioremediator
glycerophosphodiesterase by fine-tuning its mechanism of hydrolysis.
</SPAN><I><SPAN lang=ES
style="FONT-SIZE: 11pt; COLOR: black; FONT-FAMILY: 'Times New Roman'">J.
Am. Chem. Soc.</SPAN></I><SPAN lang=ES
style="FONT-SIZE: 11pt; COLOR: black; FONT-FAMILY: 'Times New Roman'">
131: 11900-11908.</SPAN><SPAN lang=EN-GB
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-GB"><o:p></o:p></SPAN></P></TD></TR>
<TR style="mso-yfti-irow: 1; mso-yfti-lastrow: yes">
<TD
style="BORDER-RIGHT: #ece9d8; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 431.9pt; PADDING-TOP: 0cm; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent"
vAlign=top width=576>
<P class=MsoNormal
style="MARGIN: 0cm 4.3pt 6pt 0cm; TEXT-ALIGN: justify; tab-stops: 9.0pt 22.5pt 45.0pt 72.0pt 108.0pt 153.0pt 162.0pt right lined 241.0pt left blank 9.0cm 297.7pt"><SPAN
lang=ES style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'">Hadler
K.S., Tanifum E.A., Yip S., Mitić N., Guddat L.W., Jackson C.J., Gahan
L.R., Nguyen K., Carr P.D., Ollis D.L., Hengge A.C., Larrabee J.A. and
Schenk G. (<B style="mso-bidi-font-weight: normal">2008</B>)
Substrate-promoted formation of a catalytically competent binuclear center
and regulation of reactivity in glycerophosphodiesterase from <I
style="mso-bidi-font-style: normal">Enterobacter aerogenes</I>. <I
style="mso-bidi-font-style: normal"><SPAN style="COLOR: black">J. Am.
Chem. Soc.</SPAN></I><SPAN style="COLOR: black"> 130:
14129-14138</SPAN><SPAN
style="mso-bidi-font-weight: bold">.</SPAN></SPAN><SPAN lang=EN-GB
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'; mso-ansi-language: EN-GB"><o:p></o:p></SPAN></P></TD></TR></TBODY></TABLE></o:p></SPAN></P></FONT></BODY></HTML>