The flexibility of the polar side chains in the alpha-helical Type I antifreeze protein (AFP) near the solution freezing temperature was investigated by two-dimensional nuclear magnetic resonance spectroscopy. These experiments were conducted to define the rotameric conformations of the proposed ice-binding groups, threonines and asparagines, in order to probe the molecular mechanism for ice binding. On the basis of the 3J alpha beta 2 NMR coupling constant values of 7.1, 8.5, 8.5, and 6.8 Hz for residues T2, T13, T24, and T35, respectively, it can be calculated that the regularly spaced ice-binding threonines sample many possible rotameric states prior to ice binding. The lack of a dominant side chain rotamer is further corroborated by nuclear Overhauser distance measurements for T13 and T24. N16 and N27, both with 3J alpha beta 2 and 3J alpha beta 3 coupling constants of 8.4 and 4.5 Hz, respectively, show a slight preference for the side chain conformation with a chi 1 of -60 degrees. These data suggest that prior to ice binding the threonine and asparagine side chains are free to rotate and that a unique preformed ice-binding structure in solution is not apparent. These observations do not support the rigid side chain model proposed recently by an X-ray study [Sicheri, F., & Yang, D. S. C. (1995) Nature 375, 427-431].
Side chain: backbone projections in aromatic and ASX residues from NMR cross-correlated relaxation
Side chain: backbone projections in aromatic and ASX residues from NMR cross-correlated relaxation
Abstract The measurements of cross-correlated relaxation rates between HNâ??N and Cβâ??Cγ intraresidual and sequential dipolar interactions is demonstrated in ASN, ASP and aromatic residues. The experiment can be used for deuterated samples and no additional knowledge such as Karplus parametrizations is required for the analysis. The data constitutes a new type of information since no other method relates the Cβâ??Cγ bond to HNâ??N. Using this method the dominant populations of rotamer...
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[NMR paper] Residual backbone and side-chain 13C and 15N resonance assignments of the intrinsic t
Residual backbone and side-chain 13C and 15N resonance assignments of the intrinsic transmembrane light-harvesting 2 protein complex by solid-state Magic Angle Spinning NMR spectroscopy.
Related Articles Residual backbone and side-chain 13C and 15N resonance assignments of the intrinsic transmembrane light-harvesting 2 protein complex by solid-state Magic Angle Spinning NMR spectroscopy.
J Biomol NMR. 2005 Apr;31(4):279-93
Authors: Gammeren AJ, Hulsbergen FB, Hollander JG, Groot HJ
This study reports the sequence specific chemical shifts...
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[NMR paper] Backbone and side-chain heteronuclear resonance assignments and hyperfine NMR shifts
Backbone and side-chain heteronuclear resonance assignments and hyperfine NMR shifts in horse cytochrome c.
Related Articles Backbone and side-chain heteronuclear resonance assignments and hyperfine NMR shifts in horse cytochrome c.
Protein Sci. 2003 Sep;12(9):2104-8
Authors: Liu W, Rumbley J, Englander SW, Wand AJ
The mutant of horse heart cytochrome c was expressed in E. coli during growth on isotopically enriched minimal media. Complete resonance assignments of both the diamagnetic reduced (spin zero) and paramagnetic oxidized (spin (1/2))...
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[NMR paper] Backbone and side-chain 13C and 15N signal assignments of the alpha-spectrin SH3 doma
Backbone and side-chain 13C and 15N signal assignments of the alpha-spectrin SH3 domain by magic angle spinning solid-state NMR at 17.6 Tesla.
Related Articles Backbone and side-chain 13C and 15N signal assignments of the alpha-spectrin SH3 domain by magic angle spinning solid-state NMR at 17.6 Tesla.
Chembiochem. 2001 Apr 2;2(4):272-81
Authors: Pauli J, Baldus M, van Rossum B, de Groot H, Oschkinat H
The backbone and side-chain 13C and 15N signals of a solid 62-residue (u-13C,15N)-labelled protein containing the alpha-spectrin SH3 domain were...
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[NMR paper] An increase in side chain entropy facilitates effector binding: NMR characterization
An increase in side chain entropy facilitates effector binding: NMR characterization of the side chain methyl group dynamics in Cdc42Hs.
Related Articles An increase in side chain entropy facilitates effector binding: NMR characterization of the side chain methyl group dynamics in Cdc42Hs.
Biochemistry. 2001 Apr 17;40(15):4590-600
Authors: Loh AP, Pawley N, Nicholson LK, Oswald RE
Cdc42Hs is a signal transduction protein that is involved in cytoskeletal growth and organization. We describe here the methyl side chain dynamics of three forms of...
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[NMR paper] NMR detection of side chain-side chain hydrogen bonding interactions in 13C/15N-label
NMR detection of side chain-side chain hydrogen bonding interactions in 13C/15N-labeled proteins.
Related Articles NMR detection of side chain-side chain hydrogen bonding interactions in 13C/15N-labeled proteins.
J Biomol NMR. 2000 Aug;17(4):305-10
Authors: Liu A, Hu W, Majumdar A, Rosen MK, Patel DJ
We describe the direct observation of side chain-side chain hydrogen bonding interactions in proteins with sensitivity-enhanced NMR spectroscopy. Specifically, the remote correlation between the guanidinium nitrogen 15Nepsilon of arginine 71,...
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[NMR paper] Investigation of a side-chain-side-chain hydrogen bond by mutagenesis, thermodynamics
Investigation of a side-chain-side-chain hydrogen bond by mutagenesis, thermodynamics, and NMR spectroscopy.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.pubmedcentral.nih.gov-corehtml-pmc-pmcgifs-pubmed-pmc.gif Related Articles Investigation of a side-chain-side-chain hydrogen bond by mutagenesis, thermodynamics, and NMR spectroscopy.
Protein Sci. 1995 May;4(5):936-44
Authors: Hammen PK, Scholtz...
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[NMR paper] Comparison of backbone and tryptophan side-chain dynamics of reduced and oxidized Esc
Comparison of backbone and tryptophan side-chain dynamics of reduced and oxidized Escherichia coli thioredoxin using 15N NMR relaxation measurements.
Related Articles Comparison of backbone and tryptophan side-chain dynamics of reduced and oxidized Escherichia coli thioredoxin using 15N NMR relaxation measurements.
Biochemistry. 1993 Jan 19;32(2):426-35
Authors: Stone MJ, Chandrasekhar K, Holmgren A, Wright PE, Dyson HJ
The backbone and tryptophan side-chain dynamics of both the reduced and oxidized forms of uniformly 15N-labeled Escherichia...