Visualizing a protein quake with time-resolved X-ray scattering at a free-electron laser.
David ArnlundLinda C JohanssonCecilia WickstrandAnton BartyGarth J WilliamsErik MalmerbergJan DavidssonDespina MilathianakiDaniel P DePonteRobert L ShoemanDingjie WangDaniel JamesGergely KatonaSebastian WestenhoffThomas A WhiteAndrew AquilaSadia BariPeter BerntsenMike BoganTim Brandt van DrielR Bruce DoakKasper Skov KjærMatthias FrankRaimund FrommeIngo GrotjohannRobert HenningMark S HunterRichard A KirianIrina KoshelevaChristopher KupitzMengning LiangAndrew V MartinMartin Meedom NielsenMarc MesserschmidtM Marvin SeibertJennie SjöhamnFrancesco StellatoUwe WeierstallNadia A ZatsepinJohn C H SpencePetra FrommeIlme SchlichtingSébastien BoutetGerrit GroenhofHenry N ChapmanRichard NeutzePublished in: Nature methods (2014)
We describe a method to measure ultrafast protein structural changes using time-resolved wide-angle X-ray scattering at an X-ray free-electron laser. We demonstrated this approach using multiphoton excitation of the Blastochloris viridis photosynthetic reaction center, observing an ultrafast global conformational change that arises within picoseconds and precedes the propagation of heat through the protein. This provides direct structural evidence for a 'protein quake': the hypothesis that proteins rapidly dissipate energy through quake-like structural motions.