title: Relationship of femtosecond-picosecond dynamics to enzyme-catalyzed H-transfer.
abstract: At physiological temperatures, enzymes exhibit a broad spectrum of conformations, which interchange via thermally activated dynamics. These conformations are sampled differently in different complexes of the protein and its ligands, and the dynamics of exchange between these conformers depends on the mass of the group that is moving and the length scale of the motion, as well as restrictions imposed by the globular fold of the enzymatic complex. Many of these motions have been examined and their role in the enzyme function illuminated, yet most experimental tools applied so far have identified dynamics at time scales of seconds to nanoseconds, which are much slower than the time scale for H-transfer between two heavy atoms. This chemical conversion and other processes involving cleavage of covalent bonds occur on picosecond to femtosecond time scales, where slower processes mask both the kinetics and dynamics. Here we present a combination of kinetic and spectroscopic methods that may enable closer examination of the relationship between enzymatic C-H → C transfer and the dynamics of the active site environment at the chemically relevant time scale. These methods include kinetic isotope effects and their temperature dependence, which are used to study the kinetic nature of the H-transfer, and 2D IR spectroscopy, which is used to study the dynamics of transition-state- and ground-state-analog complexes. The combination of these tools is likely to provide a new approach to examine the protein dynamics that directly influence the chemical conversion catalyzed by enzymes.
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Cheatum
authors.forename: Amnon
authors.initials: A
authors.lastname: Kohen
mesh_terms: D002384:Catalysis; D004798:Enzymes / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D007700:Kinetics; D013055:Spectrophotometry, Infrared; D013696:Temperature
chemical_list: D004798:Enzymes; D006859:Hydrogen
references.citation: J Chem Phys. 2004 Dec 22;121(24):12431-46
references.pmid: 15606264
references.citation: Chem Biol. 1998 May;5(5):R105-13
references.pmid: 9578637
references.citation: J Am Chem Soc. 2010 Dec 29;132(51):18367-76
references.pmid: 21142083
references.citation: J Phys Chem B. 2007 Jul 12;111(27):7852-61
references.pmid: 17571875
references.citation: Biochemistry. 2007 Dec 11;46(49):14188-97
references.pmid: 17999469
references.citation: Annu Rev Biochem. 2006;75:519-41
references.pmid: 16756501
references.citation: J Am Chem Soc. 2012 Jan 25;134(3):1738-45
references.pmid: 22171795
references.citation: Science. 2004 Jan 9;303(5655):186-95
references.pmid: 14716003
references.citation: Biochemistry. 2004 Dec 28;43(51):16046-55
references.pmid: 15609999
references.citation: J Phys Chem A. 2005 Oct 27;109(42):9424-36
references.pmid: 16866391
references.citation: J Chem Phys. 2007 Sep 28;127(12):124503
references.pmid: 17902917
references.citation: J Chem Phys. 2005 Feb 1;122(5):54506
references.pmid: 15740338
references.citation: J Biol Chem. 2001 Mar 2;276(9):6234-42
references.pmid: 11087744
references.citation: Proc Natl Acad Sci U S A. 2011 Sep 27;108(39):16159-63
references.pmid: 21930950
references.citation: J Phys Chem B. 2010 Oct 28;114(42):13536-44
references.pmid: 20883003
references.citation: Annu Rev Biochem. 1995;64:721-62
references.pmid: 7574499
references.citation: Proc Natl Acad Sci U S A. 2011 Aug 23;108(34):14115-20
references.pmid: 21831831
references.citation: Biophys J. 2007 May 15;92(10):3652-62
references.pmid: 17446536
references.citation: J Am Chem Soc. 2003 Jul 23;125(29):8718-9
references.pmid: 12862454
references.citation: J Am Chem Soc. 2005 Oct 19;127(41):14279-89
references.pmid: 16218622
references.citation: J Am Chem Soc. 2011 May 4;133(17):6692-702
references.pmid: 21476498
references.citation: Science. 2006 Sep 15;313(5793):1638-42
references.pmid: 16973882
references.citation: J Phys Chem B. 2005 Sep 8;109(35):16959-66
references.pmid: 16853158
references.citation: J Am Chem Soc. 2006 Oct 18;128(41):13356-7
references.pmid: 17031938
references.citation: Proc Natl Acad Sci U S A. 2008 Jun 24;105(25):8619-24
references.pmid: 18562286
references.citation: Proc Natl Acad Sci U S A. 2007 Dec 4;104(49):19309-14
references.pmid: 18042705
references.citation: Chem Rev. 2010 Dec 8;110(12):PR41-67
references.pmid: 21141912
references.citation: Proc Natl Acad Sci U S A. 2009 Oct 13;106(41):17359-64
references.pmid: 19805169
references.citation: Proc Natl Acad Sci U S A. 1998 Dec 22;95(26):15315-20
references.pmid: 9860966
references.citation: Biochemistry. 2006 Feb 7;45(5):1383-92
references.pmid: 16445280
references.citation: Proc Natl Acad Sci U S A. 2010 Oct 19;107(42):17974-9
references.pmid: 20876138
references.citation: Eur J Biochem. 2002 Jul;269(13):3113-21
references.pmid: 12084051
references.citation: Biochemistry. 2003 Jan 21;42(2):248-56
references.pmid: 12525151
references.citation: Biochemistry. 2011 Jul 26;50(29):6462-8
references.pmid: 21688781
references.citation: Acc Chem Res. 2006 Feb;39(2):93-100
references.pmid: 16489728
references.citation: Phys Chem Chem Phys. 2009 Oct 1;11(37):8119-32
references.pmid: 19756266
references.citation: Biochemistry. 1993 Jun 1;32(21):5503-7
references.pmid: 8504071
references.citation: Philos Trans R Soc Lond B Biol Sci. 2006 Aug 29;361(1472):1399-415
references.pmid: 16873127
references.citation: J Am Chem Soc. 2006 May 3;128(17):5636-7
references.pmid: 16637621
references.citation: J Am Chem Soc. 2011 May 4;133(17):6681-91
references.pmid: 21469666
references.citation: J Mol Biol. 2003 Mar 21;327(2):549-60
references.pmid: 12628257
references.citation: J Chem Phys. 2011 Aug 7;135(5):055106
references.pmid: 21823737
references.citation: Biochemistry. 1991 Dec 10;30(49):11567-79
references.pmid: 1747376
references.citation: J Am Chem Soc. 2011 Mar 23;133(11):3995-4004
references.pmid: 21348488
references.citation: Biochemistry. 1997 Jan 21;36(3):586-603
references.pmid: 9012674
references.citation: Phys Chem Chem Phys. 2011 Feb 14;13(6):2237-41
references.pmid: 21116553
references.citation: J Phys Chem B. 2012 Jan 12;116(1):542-8
references.pmid: 22126535
references.citation: J Am Chem Soc. 2010 Jul 21;132(28):9820-5
references.pmid: 20575541
references.citation: Proc Natl Acad Sci U S A. 2008 Feb 5;105(5):1472-7
references.pmid: 18040050
references.citation: J Am Chem Soc. 2009 Jul 29;131(29):10151-5
references.pmid: 19621965
references.citation: J Mol Biol. 1994 Feb 25;236(3):759-85
references.pmid: 8114093
references.citation: Science. 2003 Sep 19;301(5640):1698-702
references.pmid: 14500975
references.citation: J Phys Chem B. 2009 Aug 20;113(33):11505-10
references.pmid: 19637848
references.citation: Proc Natl Acad Sci U S A. 2005 Apr 5;102(14):5032-7
references.pmid: 15795383
references.citation: Philos Trans R Soc Lond B Biol Sci. 2006 Aug 29;361(1472):1307-15
references.pmid: 16873118
references.citation: J Phys Chem B. 2011 Sep 29;115(38):11294-304
references.pmid: 21823631
references.citation: Chem Biol. 1999 Jul;6(7):R191-8
references.pmid: 10381408
references.citation: Science. 2006 Apr 14;312(5771):237-41
references.pmid: 16614214
references.citation: J Phys Chem A. 2007 Oct 11;111(40):10020-5
references.pmid: 17867661
references.citation: J Am Chem Soc. 2010 Aug 18;132(32):11329-35
references.pmid: 20698699
references.citation: Proc Natl Acad Sci U S A. 2007 Jan 9;104(2):507-12
references.pmid: 17202258
references.citation: Proc Natl Acad Sci U S A. 2005 May 10;102(19):6807-12
references.pmid: 15811945
references.citation: J Phys Chem B. 2008 Aug 14;112(32):10054-63
references.pmid: 18646797
references.citation: J Phys Chem Lett. 2010 Mar 4;1(5):850-855
references.pmid: 20228945
references.citation: J Chem Phys. 2008 May 28;128(20):204505
references.pmid: 18513030
references.citation: Science. 2003 Aug 29;301(5637):1196-202
references.pmid: 12947189
references.citation: J Phys Chem B. 2010 Nov 25;114(46):15331-44
references.pmid: 20964430
references.citation: Science. 2011 Apr 8;332(6026):234-8
references.pmid: 21474759
references.citation: Angew Chem Int Ed Engl. 2008;47(3):537-40
references.pmid: 18058788
references.citation: Proc Natl Acad Sci U S A. 2007 Oct 9;104(41):16116-21
references.pmid: 17916624
references.citation: Biochemistry. 2004 Feb 24;43(7):1998-2006
references.pmid: 14967040
references.citation: Biochemistry. 2003 Nov 25;42(46):13558-75
references.pmid: 14622003
references.citation: Biochemistry. 1997 Apr 8;36(14):4212-22
references.pmid: 9100016
references.citation: J Am Chem Soc. 2004 Apr 21;126(15):4778-9
references.pmid: 15080672
references.citation: Biochemistry. 1995 Sep 5;34(35):11037-48
references.pmid: 7669761
references.citation: Anal Biochem. 2010 Dec 15;407(2):241-6
references.pmid: 20705046
references.citation: Proc Natl Acad Sci U S A. 2006 Oct 24;103(43):15753-8
references.pmid: 17032759
references.citation: Biochemistry. 2001 Aug 21;40(33):9846-59
references.pmid: 11502178
references.citation: J Am Chem Soc. 2008 Jan 9;130(1):22-3
references.pmid: 18067303
references.citation: Proc Natl Acad Sci U S A. 2007 Feb 20;104(8):2637-42
references.pmid: 17296942
references.citation: Biochemistry. 2012 May 22;51(20):4147-56
references.pmid: 22568562
references.citation: Biochemistry. 2007 Mar 27;46(12):3704-13
references.pmid: 17328531
references.citation: J Biol Chem. 1967 Jan 10;242(1):109-13
references.pmid: 5334158
references.citation: Nature. 1999 Jun 3;399(6735):496-9
references.pmid: 10365965
references.citation: Biochemistry. 2011 Jun 28;50(25):5799-805
references.pmid: 21619030
references.citation: Biochemistry. 2003 Jan 21;42(2):239-47
references.pmid: 12525150
references.citation: J Phys Chem A. 2009 Mar 12;113(10):2176-82
references.pmid: 19182971