http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Anisotropic c − f Hybridization in the Kondo Semiconductor CeFe2Al10
Yuji Muro,Keiske Yutani,Jumpei Kajino,Takahiro Onimaru,Toshiro Takabatake 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3
We report a single-crystal study on the Kondo semiconductor CeFe2Al10 in which we measuredthe magnetic susceptibility, electrical resistivity, thermopower and thermal conductivity. The highlyanisotropic behavior in all measurements indicates an anisotropic electronic structure that couldoriginate from a c−f hybridization in an orthorhombic YbFe2Al10-type structure. The anisotropicc−f hybridization effect is manifested in the different peak temperatures of the electrical resistivityand the thermopower along the three principal axes.
Nishio, Kazuya,Ogasahara, Kyoko,Morimoto, Yukio,Tsukihara, Tomitake,Lee, Soo Jae,Yutani, Katsuhide Blackwell Publishing Ltd 2010 FEBS JOURNAL Vol.277 No.9
<P>To understand the basis for the lower activity of the tryptophan synthase β<SUB>2</SUB> subunit in comparison to the α<SUB>2</SUB>β<SUB>2</SUB> complex, we determined the crystal structures of apo‐β<SUB>2</SUB> and holo‐β<SUB>2</SUB> from <I>Escherichia coli</I> at 3.0 and 2.9 Å resolutions, respectively. To our knowledge, this is the first report of both β<SUB>2</SUB> subunit structures with and without pyridoxal‐5′‐phosphate. The apo‐type molecule retained a dimeric form in solution, as in the case of the holo‐β<SUB>2</SUB> subunit. The subunit structures of both the apo‐β<SUB>2</SUB> and the holo‐β<SUB>2</SUB> forms consisted of two domains, namely the N domain and the C domain. Although there were significant structural differences between the apo‐ and holo‐structures, they could be easily superimposed with a 22° rigid body rotation of the C domain. The pyridoxal‐5′‐phosphate‐bound holo‐form had multiple interactions between the two domains and a long loop (residues 260–310), which were missing in the apo‐form. Comparison of the structures of holo‐<I>Ec</I>β<SUB>2</SUB> and <I>St</I>β<SUB>2</SUB> in the α<SUB>2</SUB>β<SUB>2</SUB> complex from <I>Salmonella typhimurium</I> (<I>St</I>α<SUB>2</SUB>β<SUB>2</SUB>) identified the cause of the lower enzymatic activity of holo‐<I>Ec</I>β<SUB>2</SUB> in comparison with <I>St</I>α<SUB>2</SUB>β<SUB>2</SUB>. The substrate (indole) gate residues, Tyr279 and Phe280, block entry of the substrate into the β<SUB>2</SUB> subunit, although the indole can directly access the active site as a result of a wider cleft between the N and C domains in the holo‐<I>Ec</I>β<SUB>2</SUB> subunit. In addition, the structure around βAsp305 of the holo‐<I>Ec</I>β<SUB>2</SUB> subunit was similar to the open state of <I>St</I>α<SUB>2</SUB>β<SUB>2</SUB> with low activity, resulting in lower activity of holo‐<I>Ec</I>β<SUB>2</SUB>.</P><P><B>Structured digital abstract</B></P><P><P>: <I>Ecβ2</I> (uniprotkb:) and <I>Ecβ2</I> (uniprotkb:) <I>bind </I>() by <I>x‐ray crystallography</I> ()</P><P>: <I>Ecβ2</I> (uniprotkb:) and <I>Ecβ2</I> (uniprotkb:) <I>bind </I>() by <I>biophysical</I> ()</P></P>