gs bNXX üªõ@ðp¢½_f­¶öÌÌ\¢ÉÖ·é¤îì~qPhysical Biosciences Division, Lawrence Berkeley National Laboratoryv |1 Cyclotron Rd., Berkeley, CA 94720, USAªð½Íõ»wn II _f­¶¡ÌiPhotosystem IICÈº PSIIjÉ¨¢Ä¨±èC»Ì
é_f­¶öÌioxygen­evolving complex, OECjÍC4 ÂÌ Mn Æ 1 ÂÌ Ca ªIL\Ë´µ½ Mn4©REÉ¨¯é«SÅ

CaO5 NX^[ÆC6 ÂÌJ{LVîC1 ÂÌqX`WîÉæÁÄ\¬³êéBäXÌO[vÅÍCPSIIÌõì®TCNÉ¨±é Mn4CaO5 NX^[Ì\¢ÆdqóÔÏ»ððµCÐ¢ÄÍ½@\»ÌàÌðð
¾·é½ßlXÈªõ@ðp¢ÄÀ±ðsÁÄ¢éB³fIð«Ìé X üªõ@Í^pN¿ÌÁè³fÌ»w\¢Ï»ðð·éÌÉÐÍð­ö·éB{eÅÍC_f­¶iªðjßöÅ¶¸é Mn4CaO5 NX^[ÌóÔÏ»ÉÖµÄCX üªõ@©ç¾çêÄ¢é»ÝÌm©ðTà·éB©REÉ¨¢ÄC¾zõGlM[ðzûµÄ¶¨ªpÂ\È»wGlM[ÉÏ··é_f­¶^õ¬½ÅÍCªOIÈdqÌ¹idq^ÌjÆµÄp¢çêéB»Ì«SÅ®É¦·Æ¨è 2 ÂÌ

é_f­¶öÌÅÍCÈºÌªqª 4 dq_»³êé±ÆÉ

æÁÄ 4 ÂÌvgÆ 4 ÂÌdqC¨æÑ 1 ªqÌ_fªúo³êéB
2H2O¨O2{4H{{4e|(1)±±Å¶¬³ê½dqÍÅIIÉdq`BÌÅéNADPHinicotinamide adenine dinucleotide phosphateC
jR`A~hAfjWkNI`h_jÌ¶¬Ép¢çêC »µÄ` RChi Nv XgàÌPSII ðÜÞõ¬^pN¿ª¶Ý·é¿ñdjÌàOÉ`¬³ê½vgZxùzÉæédÊðpµÄ¬³êé ATPiAdenosine TriphosphateCAfm
VO_jÆÆàÉCCO2 ðÉÒ³·éÌÉp³êé1)Bªð½ÍCMn4CaO5 NX^[É¨¯é½ÔÌ Sn in0`4jÌõì®TCNiKok cyclejÉæÁÄ¨±éiFig. 1)2) Bn ªå«¢ÙÇæè_»ªiñ¾óÔð\µCPSII ª 1 õÊqðzû·é²ÆÉ 1 Xebv
¸Â_»½ªis·éiSn¨Sn{1jBÜ¸ PSII ðÃ¢Æ
±ëÉ 1 Ôöx¨¢ÄâéÆ S1 óÔÅÀè»³êéiÃjBS1 óÔÍC½SÅéNtB a ñÊÌ P680ÌõUNÉºÁÄ S2CS3 ÖÆ 1 dq¸Â_»³êéB»µÄ 3 ñÚÌõãNãÉõ½ÌZ¢ S4 óÔðoFig. 1(Color online) (top) PS II monomer structure showing thelocation of the reaction center pigments, P680, pheophytins(Pheo), the donor OEC, and acceptor side Fe and quinones
QA and QB3,4). (bottom left) The Kok cycle with the S­stateintermediates, proposed oxidation states, and kinetics. The
inset shows the proposed structure of the S1 state of theMn4CaO5 cluster from EXAFS, EPR, and theoretical studies
based on the XRD structure.

Ä 1 _fªqðV£µ½ãCS0 óÔÖßéBõì®TCNÉ¨¢Ä¨±é Mn4CaO5 NX^[eS óÔÌ\¢ÆdqóÔÏ»CEvg»C¨æÑî¿84  úËõ March 2013 Vol.26 No.2(C) 2013 The Japanese Society for Synchrotron Radiation ResearchgsbNX ¡ X üªõ@ðp¢½_f­¶öÌÌ\¢ÉÖ·é¤ªqÌð·»ÛÉÂ¢ÄÍCX ü\¢ðÍ@¨æÑlXÈªõ@ðp¢½À±Æ_ðÍðÊµÄæÉ¾ç©
ÉÈèÂÂéBµ©µ»ÌêûCªð@\»ÌàÌÉ

ÖµÄÍ¢¾ð¾³êÄ¨ç¸C»ÝàlXÈûÊ©ç¤ª±¯çêÄ¢éB^pN¿Ì\¢ðméè@ÍCúËõ X ü¹ðpµÄs¤P» X ü\¢ðÍª¢¤ÜÅàÈ­»Ìå½éû@Åé3_5)Bæè¬³È»©çæè¢ªð\Ìf[^ð¾é½ßCæ 3 ¢ãúËõ{ÝÌæ¤ÈPx
ÌúËõ¹ªp³êÄ¢éB»ÌêûÅCªèÉN±è¤é¿ÌúËü¹ÍCX üðp¢é¤ÉíÉ¶Ý·éâèÅèC¿Ì¹Ìöxð¢©ÉµÄ]¿µC©ÂÅáÀÉ¯ßÄ«^\¢ð¾é©ªÛèÅé6)BPSII Ìæ¤Èà®^pN¿ÌêC»Ìà®«SÌ\¢ð²×éÊÌû@ÆµÄCX üzûiXASj@ªL­p¢çêÄ¢éBXAS @ðà®^pN¿Ép·éÛÌ_ÍCÜ¸ EXAFS XyNg©çÍC«StßÌ´qÔÌ£ÉÖ·éîñð¢¸xi
£ªð\FPSII Ì Mn EXAFS ÌêC¨æ»0.10©çFig. 2 (Color online) Mn and Sr EXAFS spectral changes of Sr­
substituted PSII (Mn4SrO5)9). For Mn EXAFS, 2.5k(/Å)
11.5 was used for Fourier Transform (k3­weighted). For
Sr EXAFS, 2k(/Å)13.5 was used.

0.15 ÅC£Ì¸xF`0.02 ÅjÅßé±ÆªÅ«é_ª°çêéBÜ½CªèÉp¢é X üÊðeÕÉ§äç S3 óÔ»ê¼êÌnt¿©ç¾çê½ Mn yÑ SrÅ«éBPSII ÌêCEXAFS ªèÉp¢é X üÊi6.6

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2.7 Å ©ç2.8 Å ÉÈéB¯lÌXyNgÏ»ª Sr­EX­±ÌÛCMn4CaO5 NX^[Í2.7 Å tßÉ 3 ÂÌ Mn_AFS f[^©çà¾çêÄ¨èCS2 ©ç S3 óÔÉ¨¯éMn ÝìpC3.3 Å tßÉ 1 ÂÌ Mn_Mn ÝìpC»\¢Ï»Í¨»ç­ Mn4Sr(/Ca)O5 NX^[SÌÌ\µÄ3.4 Å tßÉ 2 Â©ç 3 ÂÌ Mn_Ca ÝìpðÂ¢Ï»ðº¤Å±Æª±êÜÅÌ EXAFS XyNgðÍ©çí©ÁÄCa ðæè­Æ S2 ©ç S3 óÔÖÌ]ÚªjQ³êé±ë¤Æl¦çêéB_f­¶öÌ©ç¢é7) BÂÜèC4 ÂÌ Mn Ôª di­m­oxoi2 ÂÌ_fÉ

Æªí©ÁÄ¢éªC±ÌÊÍ S2 ¨S3 óÔ]ÚÉ¨¢é¢Í mono­m­oxo Ë´i1 ÂÌ_f

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Æ  K  h i O / N j Ô Ì ½ Ï  £ Í 1.87 Å ÅÔÌ£ÆàÉ S1 óÔÆär·éÆ·­ÈÁÄ¨èC¨éBë¤ 3 ÂÌ 3 ¿ Mn Ì Jahn­

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»ç­ S0 É¶Ý·éÅç¾çê½ Mn4CaO5 NX^[Ìô½wI\¢3) CyÑTeller øÊÌe¿ÉæéàÌÆl¦çêéB

EPRielectron paramagnetic resonance spectroscopyCd

êûCS3 óÔ©ç_fðúoµÄ S0 óÔÖßéßöÅqXs¤Â@)8) ©çÌf[^ðÆçµí¹éÆCS1»êéÀèÈÔÌiS4 óÔjÍC¼Ì S ÔóÔÌóÔÉ¨¢ÄNX^[Í Fig. 1(bottom) É¦·æ¤È»æ¤É[U[ÆËÆ±­}â@ÉæÁÄÍÆç¦é±Æw\¢ðÆéÌÅÍÈ¢©Æl¦çêéBªÅ«È¢½ßC»Ì¨»wI«¿ÉÖµÄÍ±êÜÅ

Mn4CaO5 NX^[Ì´qÔ£ÍCS óÔ]ÚÉ

ÌÆ±ëÙÆñÇí©ÁÄ¢È¢Bº¢»Ì»w\¢Ï»ð½fµÄí¸©ÉÏ»·éB±±ÅCõ¬×Û T. elongatus ð Sr Â«ºiCa t[jÅ|{µÄ¾çêé Mn4SrO5 NX^[ðp¢Ä Mn yÑSr Ì EXAFS ªèðs¢CNX^[Ì\¢Ï»ð²×½BSr u·^Ì PSII É¨¢Äà_f­¶½ÍÛ³ê
é±Æª±êÜÅÌ¤©çí©ÁÄ¢éBFig. 2 É S0 ©

úËõ March 2013 Vol.26 No.2  85ìpxNgirjÌ»ÅÌzüÆüË X üd¥gx

3. Îõ XAS @NgiejÌÈ·px u É cos2 u ÌÖWÅË¶·éB]OÅÍCPSI Int¿ðp¢½ EXAFS XyNg

ÁÄC»ÌûÊðÏ¦ÄÎõXyNgðªè·é±ÆÌÊð¦µ½ªCÁ¦Ä PSII Ì 2 ³züâP»ÉæÁÄC»C³çÉÍªqÅÌÁèÌÝìpÌÈÇÌzü¿ÌÎõ EXAFS ªèðs¤±ÆÅ´qÔzüûüðè·é±ÆªÅ«éB³çÉCnt¿ÌXÝìpÌzü«ðmé±ÆªÅ«éBúËõ X üÍüÎõÁ«ªé½ßCüË X üÌd¥gxNgiejÉÎµÄ»ÌûÊðÏ¦é±ÆÉæèC»ûÊÉË¶µyNgÅÍûüIÉ½Ï»³êÄª£sÂ\ÅÁ½¬ªð »Ìûü Ë¶«Éæ ÁÄª£·é ±ÆªÂ\ Åé10)BX^tH[húËõ{Ý BL9_3 ÌP»p XAS ½ÎõXyNgª¾çêéBÎõ EXAFS XyNg

uð Fig. 3 É¦·BJbp[SjI[^[Éæèt¯çÌzûfÊÏisjÍÌ®Å\·±ÆªÅ«éBsåc|qqf|eÉr|qir|2ccos2 u|qqf|r|qir|2±±ÅCc ÍèCqf Æ qi ÍnóÔÆIóÔÌg®ÖCê½P»ÍCtÌwE«t¯uÉæÁÄ¨æ»
10 K ÉÛ³êéBº¬¤ÉÝuµ½ X üñÜpoíðp¢Äªèµ½ñÜp^[©çe»ÌûÊðmé±ÆªÅ«éBñÜp^[ðàÆÉÚIÌ»ûÊðèe ÍüË X üd¥gxNgûüÌPÊxNgCr ÍJãCXAS poíiGe oíjÉæÁÄ XAS XyNg

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Fig. 4 ÉCPSII »Ìe unit cell ²ûüÌÎõ EXAFSXyNgð¦·11) BPSII Ì»iqóÔQÍ P212121ÅèC»iqÉ 4 ÂÌ PSII _C}[ðÜÞBÂÜèC}É¦µ½ÎõXyNgÍC8 ÂÌ PSII m}[Ìñ^ðÜÞB¾çêéÎõÁ«©çCPSII ^pN¿
ÅÌ Mn4CaO5 NX^[Ì¨¨æ»ÌzüûüÉÖ·éîñðè·é±ÆªÅ«éBÂÜèCP»ðp¢½EXAFS XyNgÌÎõÁ«ÍCÂ\Èf\¢ðièÞÌÉñíÉLøÅéB

Ü½Cnt¿Æ¯lÌû@i[U[ÆËÆ±­}â@jðp¢é±ÆÉæÁÄCPSII »É¨¢Äà S óÔÏ»ðUN·é±ÆªÂ\ÅèC\¢Ï»Ìûü«É

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Fig. 3(Color online) Single crystal XAS setup at Stanford Syn­chrotron Radiation Lightsource, BL 9_3.

Fig. 4

Mn4CaO5 NX^[ÌKhÍCË´_fÆJ{(Color online) Single crystal EXAFS spectra of the PSII S1 state, which was collected along the crystal unit cellaxes.

86  úËõ March 2013 Vol.26 No.2

gsbNX ¡ X üªõ@ðp¢½_f­¶öÌÌ\¢ÉÖ·é¤LVîÉR·é[_fCî¿ªqÌ_f´qCyÑqX`WîÉR·éf´qªêÂ¶Ý·é12) Bªð\1.9 Å Ì»\¢É¨¢ÄCMn ÉÎµÄ 5 ÂÌJ{LVîÍñzÀibidentatejC1 ÂÌJ{LVîÍPÀzÊimonodentatejµÄ¢éBÜ½C4 ÂÌªqÌ¤¿ 2 ªqª[Ì MnCcèª Ca ÉzÊµÄ¢é3)BS ÔÌÌ]ÚßöÅÍCEvg»óÔàÜß½KhÂ«ÌÏ»ª¨±éÆl¦çêéBá¦ÎC_f­¶öÌÌEvg»ÍC1(S0¨S1)F0(S1¨S2)F1(S2¨S3 )F2(S3 ¨S0 ) ÌÅ¨±é±ÆªlXÈÀ±ÊÉæÁÄx³êÄ¢é13)BÜ½CMn4CaO5 NX^[ªªqðÇÌiKÅÇÌÊuÉæèÞ©CÆ¢¤±ÆÍªð½ðð·éãÅñíÉdvÈÛèÅéBµ©

µC^pN¿Å¨±éKhÌæ¤Èy³fÌ\¢Ï»ðÆç¦éÌÍ^pN¿É½­¶Ý·é¼Ìy³f©çÌVOiªå«ÈobNOEhÉÈé½ßñíÉ¢ïÅ

éB1 ÂÌÔÚIè@ÆµÄCÁèA~m_cîÌÏÙÌðp¢Ä»ê¼êÌKhÌððð¾·éû@ª°çêé14)BFig. 5 ÉqX`WcîðO^~_îÉu·µ½ PSII ÏÙiHis332GlujÌÃóÔ
iS1jÌ EXAFS XyNgð¦·Bì¶Ì S1 óÔÆÏÙÔÌXyNgÏ»©çC1 ÂÌA~m_cîÌu·ÉæÁÄ Mn4CaO5 NX^[Ì\¢ªå«­Ï»µ½±Æªí©éBMn ÆKhCyÑ Mn_Mn £ 2.7 Å É
·és[NªVtgµÄ¨èC»êçÌ´qÔÝìpª·­ÈÁÄ¢éiMn ÆKhF1.87 Å¨1.89 ÅCMn_MnF2.72 Å¨2.77 Åj±Æð¦µÄ¢éBÂÜèC
PSII É¨¢ÄCMn4CaO5 NX^[üÍÌKhÂ«ª\¢Æ»Ìªð½@\Éå«­ñ^µÄ¢é±Æð¦´·éBMn_Mn ÔÌ£ª0.05 Å öx·­ÈéRÆµÄÍCá¦ÎË´_fÌvg»CÅé¢ÍñzÀÁ½J{LVîªPzÀÉÈéæ¤È»wÏ»ªFig. 5(top) Mn EXAFS spectra of native PSII S1 state (black) andHis332Glu mutant in the dark (S1) state (gray). (bottom)(a, b) possible structural changes caused by the histidine toglutamate mutation14).

l¦çêéB
KhÂ«ðméà¤êÂÌû@ÆµÄCÅíèO
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Ñ KbXyNgÌ`óÉe¿ðyÚ·±ÆªúÒ³ê»³ê½ãÌÉaßöÉ¨¢Ä¨±é­õ X üÌ¤¿CXé17)B½¾µ{À±ÅÍCñíÉã¢ Kb2,5 ¨æÑ Kbé Kb
XyyNgðóÈiMn: `1 mMj^pN¿ÌnÅ¢©

õ@ªé15) B1s O¹ãÌdqªãNC

Kb2,5 XyNgÆ»ÌTeCgs[NÅNgÍÅíèO¹©ç Mn Ì 1s O¹ÖÌJÚÉÉµÄø¦æ­ªè·é©CÆ¢¤±ÆªâèÆÈéB¡·éBKb2,5 XyNgªåÉKhÌ 2p O¹©çÌãfbh^CðZ­·é±ÆâªõíÌ§ÌpðJÚÅéÌÉÎµÄCKbXyNgÍKhÌ 2swÍÈÇªKvÅ°ééBO¹©ç Mn Ì 1s O¹ÖÌJÚÉR·éBµ½ªÁ
ÄC±êçÌXyNgÌGlM[ÊuÆ­xÍà®É¼Úµ½KhÌíÞiN, O, C ÈÇjC»Ìvg»óÔCà®´q_KhÔÌ­xÈÇÉË¶·é±Æªí©ÁÄ¢é15,16) BFig. 6 É PSII Ì SÑ Mn f»¨Ì KbXyNgð¦·B1 óÔy5. ¡ãÌW]_XFEL ÌpãLÌÅq×½Æ¨èCPSII Ì S0, S1, S2 CyÑ S3
óÔÌæ¤ÈärIÀèÈÔóÔÍC}â@ÅÆç¦é±ÆªÂ\ÅèC³Ü´ÜÈªõè@ðp¢ÄtÌwúËõ March 2013 Vol.26 No.2  87

Fig. 6(a) Logarithmic plot of the MnO Kb spectrum. The O­Mn cross­over Kbtransition is highlighted. (b) Energy
diagram of Mn Kb transitions in MnO. The Kband Kb2,5 transitions are from valence molecular orbitals; Kbisthe O 2s to Mn 1s `cross­over' transition. (c) The Kbemission spectra from a series of multinuclear Mn complex­
es with oxo­bridging groups, a MnV­oxo complex and PS II in the S1 state. The crossover peak from the O ligand
is prominent when short bridging Mn_O distances are present17).

EâtÌf·xºÅXyNgªè·é±ÆªÅ«­õ@Ì¯ªèðÝÄ¢éiFig. 7)18,19)BX üñÜpéBêûÅCS4 óÔÌæ¤ÈsÀèÈÔóÔÍ±êÜ^[©çÍ»\¢ÉÖ·éîñªC»µÄ¯É XÅÌÆ±ë¯lÌû@ÅÍÆç¦é±ÆªÅ«Ä¢È¢Bü­õXyNg©çÍNX^[Ìd×óÔâ»w\¢»Ìæ¤ÈÔÌÉÖµÄÍCº·ÅÔªðªèðsÏ»ÉÖ·éîñð¾é±ÆªÅ«é19) B±êÜÅÌÀ

¢C½ðoIÉÇ¤è@ªKµÄ¢éÆl¦çêéB±Ê©çCº·É¨¢Äà PSII S1 P»Ì\¢f[^»ÌÛC^pN¿¿Ì X üðp¢½è@ÅâèÆÈ

ª¾çêé±ÆC»µÄ­xÌ­¢ X ü©Rdq[éÌÍCqhLVWJÌgUi`sRbjÉæéU[ðp¢ÄàúËõ¹©ç¾çêéæ¤ÈÊíÌ X ü¿Ì X ü¹ÅéB±¤¢Á½nÉ¨¢ÄÍCÅß­õXyNgª¾çêé±ÆðmFµÄ¢é20) B]Á

pÂ\ÉÈÁ½ X ü©Rdq[U[ªÐÍð­ö·éBÄCX ü©Rdq[U[ðp¢½¤ÍC_f­¶½

X ü©Rdq[U[ðp¢½À±ÅÍCñíÉZ¢pÔÌÌ¨«ð¾ÌÝÈç¸C¶Ì¿êÊÌº·É¨

Xi`50tFgbjÌ X üi`1012 photons/pulsej¯é X ü\¢ðÍâ X üªõ@ÉLøÈè@ÆµÄ¡ãðp¢Äªèðs¤BpXªWJÌgU¬xæèÜ·Ü·p¢çêé±ÆªúÒ³êéBàZ¢½ßCº·É¨¢Äà X ü¹ÌÈ¢f[^ð¾é±ÆªÅ«éBÓ«äXÌO[vÅÍCX ü©Rdq[U[{ÝÉ¨{¤Í DOE (Director, Oce of Science, Oce of¢Ä~NTCYÌ PSII P»Ì X üñÜ@Æ X ü

Basic Energy Sciences, Contract: DE_AC02_05CH11231),

88  úËõ March 2013 Vol.26 No.2

gsbNX ¡ X üªõ@ðp¢½_f­¶öÌÌ\¢ÉÖ·é¤Fig. 7 (Color online) (Top) The setup for the simultaneous XRD/XES experiment at LCLS (Linac Coherent Light
Source, Stanford). The injector delivers the crystals/solutions to the interaction region of the optical laser pump and X­
ray laser probe. The XRD detector is downstream, and the XES spectrometer and position sensitive detector (PSD) at 90
degrees to the X­ray beam. The inset (top right) is the energy­dispersive XES spectrometer with 16 analyzer crystals5).
Bottom panels (left) show the energy level diagram for K emission lines, (right) shows the energy dispersive scheme forcollecting the entire spectrum in a shot­by­shot mode on the PSD.

NIH (National Institute of Health, GM 55302) ÉæÁÄx³êÄ¢éB¤¯¤ÒÅé Drs. Vittal K. Yachan­dra, Jan Kern, Rosalie Tran, Roberto Alonso Mori, UweBergmann É´Ó·éBúËõ{ÝÍ StanfordSynchro­tron Radiation Lightsource (SSRL) ðpµC{¤Í»

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5)

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18)

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îì~qLawrence Berkeley National Laboratory,
Physical Biosciences Division, Sta
ScientistE­mail: JYanolbl.gov
êåFúËüÈwCU®ªõC¶¨¨»wmªðn
Låw¶¨Èw¤ÈmÛöOúC
¹CLåw¶¨¶YwèCåãåwwªqwÈ_¶miwjCGolda
Meir Research Fellow, Lawrence BerkeleyNational Laboratory ¤õðoÄ»EBX­ray spectroscopy study of the oxygen­evolving
complex in Photosystem IIJunko YANO
Abstract

Physical Biosciences Division, Lawrence Berkeley National Laboratory
1 Cyclotron Road, MS: 66R0200 Berkeley, CA 94720 USA

Oxygen, that supports all aerobic life, is abundant in the atmosphere because of its constantregeneration by photosynthetic water oxidation, which is catalyzed by a Mn4CaO5 cluster in Pho­tosystem II (PS II), a multi subunit membrane protein complex. The structure of PS II and the cata­
lytic intermediate states have been studied intensively over the past several years and various X­
ray spectroscopy techniques have provided useful information about the structure and electronic
structure of the Mn4CaO5 cluster. This topic describes a brief review of the various X­ray spec­
troscopic techniques that are critical for understanding of the Mn4CaO5 cluster, and also mentions
future direction using X­ray Free Electron Laser facilities that can be used for following the reac­tion in real time at room temperature using crystallography and X­ray spectroscopy.

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