Decomposition of vibrational shifts of nitriles into electrostatic and hydrogen-bonding effects.
Infrared (IR) band shifts of isolated vibrational transitions can serve as quantitative and directional probes of local electrostatic fields, due to the vibrational Stark effect. However, departures from the Stark model can arise when the probe participates in specific, chemical interactions, such as direct hydrogen bonding. We present a method to identify and correct for these departures based on comparison of (13)C NMR chemical shifts and IR frequencies each calibrated in turn by a solvatochromic model. We demonstrate how the tandem use of these experimental observables can be applied to a thiocyanate-modified protein, ketosteroid isomerase, and show, by comparison to structural models, that changes in electrostatic field can be measured within the complex protein environment even in the background of direct hydrogen bonding to the probe.
Fafarman
Aaron T
AT
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Sigala
Paul A
PA
Herschlag
Daniel
D
Boxer
Steven G
SG
D020134:Catalytic Domain; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D009570:Nitriles / Q000737:chemistry*; D016958:Pseudomonas putida / Q000201:enzymology; D013055:Spectrophotometry, Infrared / Q000379:methods*; D055672:Static Electricity; D013251:Steroid Isomerases / Q000737:chemistry; D014732:Vibration
D009570:Nitriles; D013251:Steroid Isomerases
Science. 2006 Jul 14;313(5784):200-4
16840693
Biochemistry. 2003 Oct 21;42(41):12050-5
14556636
Biochemistry. 2009 Jul 28;48(29):6932-9
19469568
J Am Chem Soc. 2006 Oct 18;128(41):13356-7
17031938
Nat Chem Biol. 2009 Jun;5(6):397-9
19396177
Biochemistry. 1997 Nov 18;36(46):14030-6
9369474
J Phys Chem Lett. 2010 Feb 1;1(4):781-786
20436926
Biochem Biophys Res Commun. 1995 Jul 6;212(1):159-64
7612000
J Am Chem Soc. 2003 Jan 15;125(2):405-11
12517152
J Am Chem Soc. 2008 May 21;130(20):6597-603
18412341
Biochemistry. 2002 Dec 31;41(52):15728-35
12501201
Biochemistry. 1991 Mar 5;30(9):2333-47
2001365
J Chem Phys. 2008 Apr 7;128(13):134506
18397076
J Am Chem Soc. 2007 Oct 10;129(40):12104-5
17854190
J Phys Chem Lett. 2010 Mar 4;1(5):850-855
20228945
Biochemistry. 2000 Jan 11;39(1):110-6
10625485
J Phys Chem B. 2009 Sep 24;113(38):12736-43
19711975
Biochemistry. 1994 Feb 15;33(6):1433-46
8312263
J Phys Chem B. 2008 May 22;112(20):6301-3
18438998
Biochemistry. 1992 Sep 1;31(34):7922-30
1510978