title: Evidence of molecular alignment fluctuations in aqueous dilute liquid crystalline media.
abstract: Protein dynamics can be studied by NMR measurements of aqueous dilute liquid crystalline samples. However, the measured residual dipolar couplings are sensitive not only to internal fluctuations but to all changes in internuclear vectors relative to the laboratory frame. We show that side-chain fluctuations and bond librations in the ps-ns time scale perturb the molecular shape and charge distribution of a small globular protein sufficiently to cause a noticeable variation in the molecular alignment. The alignment variation disperses the bond vectors of a conformational ensemble even further from the dispersion already caused by internal fluctuations of a protein. Consequently RDC-probed order parameters are lower than those obtained by laboratory frame relaxation measurements.
authors: Department of Physical Sciences, University of Helsinki, Gustaf Hällströmin katu 2, Helsinki 00014, Finland. m.j.louhivuori@rug.nl
authors: Martti
authors: M
authors: Louhivuori
authors: Renee
authors: R
authors: Otten
authors: Tapio
authors: T
authors: Salminen
authors: Arto
authors: A
authors: Annila
mesh_terms: D002135:Calcium-Binding Proteins / Q000737:chemistry; D003198:Computer Simulation; D003460:Crystallization; D006801:Humans; D006860:Hydrogen Bonding; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D017434:Protein Structure, Tertiary; D025801:Ubiquitin / Q000737:chemistry
chemical_list: D002135:Calcium-Binding Proteins; D025801:Ubiquitin
references: J Am Chem Soc. 2003 Jul 16;125(28):8639-43
references: 12848571
references: Biophys J. 2004 Jun;86(6):3444-60
references: 15189846
references: J Biomol NMR. 2006 Feb;34(2):101-15
references: 16518697
references: J Am Chem Soc. 2002 Jun 5;124(22):6449-60
references: 12033876
references: J Comput Chem. 2003 Nov 15;24(14):1691-702
references: 12964188
references: Biochemistry. 1981 Aug 4;20(16):4618-28
references: 7197547
references: Biochemistry. 1999 Jul 13;38(28):9013-22
references: 10413474
references: Curr Opin Struct Biol. 2005 Oct;15(5):563-70
references: 16140525
references: J Am Chem Soc. 2004 Jan 28;126(3):698-9
references: 14733527
references: J Am Chem Soc. 2001 Feb 21;123(7):1416-24
references: 11456715
references: J Magn Reson. 1999 Jun;138(2):334-42
references: 10341140
references: Eur J Biochem. 2003 Jun;270(11):2505-12
references: 12755706
references: Chem Rev. 2004 Aug;104(8):3519-40
references: 15303825
references: J Am Chem Soc. 2003 Jul 9;125(27):8072-3
references: 12837055
references: Biochemistry. 2004 Aug 24;43(33):10678-91
references: 15311929
references: Biochemistry. 1989 Nov 14;28(23):8972-9
references: 2690953
references: J Am Chem Soc. 2006 Apr 5;128(13):4371-6
references: 16569014
references: J Am Chem Soc. 2002 Jun 5;124(22):6439-48
references: 12033875
references: J Mol Biol. 2001 May 11;308(4):745-64
references: 11350172
references: Eur Biophys J. 2006 Jan;35(2):170-80
references: 16249916
references: Chem Rev. 2004 Aug;104(8):3623-40
references: 15303831
references: J Am Chem Soc. 2001 Jun 27;123(25):6098-107
references: 11414844
references: J Am Chem Soc. 2005 Dec 28;127(51):17968-9
references: 16366524
references: Biochemistry. 1977 Jun 14;16(12):2657-67
references: 889782
references: J Phys Chem B. 1998 Apr 30;102(18):3586-616
references: 24889800
references: J Magn Reson. 2005 May;174(1):43-53
references: 15809171
references: J Biomol NMR. 2003 Nov;27(3):261-75
references: 12975584
references: J Am Chem Soc. 2004 Jun 30;126(25):7760-1
references: 15212507
references: J Am Chem Soc. 1972 Apr 19;94(8):2657-60
references: 5017418
references: J Am Chem Soc. 2006 Aug 30;128(34):11072-8
references: 16925424
references: J Am Chem Soc. 2002 Oct 9;124(40):12020-30
references: 12358549
references: Proc Natl Acad Sci U S A. 2005 Sep 27;102(39):13885-90
references: 16172390
references: J Am Chem Soc. 2002 May 22;124(20):5822-33
references: 12010057
references: J Am Chem Soc. 2004 Mar 10;126(9):2923-38
references: 14995210
references: Angew Chem Int Ed Engl. 2005 Dec 2;44(47):7776-8
references: 16276548
references: Methods Enzymol. 2001;339:127-74
references: 11462810
references: Science. 1997 Nov 7;278(5340):1111-4
references: 9353189
references: Nat Struct Biol. 2001 Nov;8(11):990-7
references: 11685248
references: J Am Chem Soc. 2003 Jul 30;125(30):9179-91
references: 15369375