首页 | 本学科首页   官方微博 | 高级检索  
     


Protein kinetics: structures of intermediates and reaction mechanism from time-resolved x-ray data
Authors:Schmidt Marius  Pahl Reinhard  Srajer Vukica  Anderson Spencer  Ren Zhong  Ihee Hyotcherl  Rajagopal Sudarshan  Moffat Keith
Affiliation:Physikdepartment E17, Technische Universit?t München, 85747 Garching, Germany. marius@hexa.e17.physik.tu-muenchen.de
Abstract:We determine the number of authentic reaction intermediates in the later stages of the photocycle of photoactive yellow protein at room temperature, their atomic structures, and a consistent set of chemical kinetic mechanisms, by analysis of a set of time-dependent difference electron density maps spanning the time range from 5 micros to 100 ms. The successful fit of exponentials to right singular vectors derived from a singular value decomposition of the difference maps demonstrates that a chemical kinetic mechanism holds and that structurally distinct intermediates exist. We identify two time-independent difference maps, from which we refine the structures of the corresponding intermediates. We thus demonstrate how structures associated with intermediate states can be extracted from the experimental, time-dependent crystallographic data. Stoichiometric and structural constraints allow the exclusion of one kinetic mechanism proposed for the photocycle but retain other plausible candidate kinetic mechanisms.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号