Related ArticlesThermodynamic and hydrodynamic properties of human tropoelastin. Analytical ultracentrifuge and pulsed field-gradient spin-echo NMR studies.
Tropoelastin is the soluble precursor of elastin that bestows tissue elasticity in vertebrates. Tropoelastin is soluble at 20 degrees C in phosphate-buffered saline, pH 7.4, but at 37 degrees C equilibrium is established between soluble protein and insoluble coacervate. Sedimentation equilibrium studies performed before (20 degrees C) and after (37 degrees C) coacervation showed that the soluble component was strictly monomeric. Sedimentation velocity experiments revealed that at both temperatures soluble tropoelastin exists as two independently sedimenting monomeric species present in approximately equal concentrations. Species 1 had a frictional ratio at both temperatures of approximately 2.2, suggesting a very highly expanded or asymmetric protein. Species 2 displayed a frictional ratio at 20 degrees C of 1.4 that increased to 1.7 at 37 degrees C, indicating a compact and symmetrical conformation that expanded or became asymmetric at the higher temperature. The slow interconversion of the two monomeric species contrasts with the rapid and reversible process of coacervation suggesting both efficiently incorporate into the coacervate. A hydrated protein of equivalent molecular weight modeled as a sphere and a flexible chain was predicted to have a frictional ratio of 1.2 and 1.6, respectively. Tropoelastin appeared as a single species when studied by pulsed field-gradient spin-echo NMR, but computer modeling showed that the method was insensitive to the presence of two species of equal concentration having similar diffusion coefficients. Scintillation proximity assays using radiolabeled tropoelastin and sedimentation analysis showed that the coacervation at 37 degrees C was a highly cooperative monomer-n-mer self-association. A critical concentration of 3.4 g/liter was obtained when the coacervate was modeled as a helical polymer formed from the monomers via oligomeric intermediates.
Complete determination of the Pin1 catalytic domain thermodynamic cycle by NMR lineshape analysis
Complete determination of the Pin1 catalytic domain thermodynamic cycle by NMR lineshape analysis
Abstract The phosphorylation-specific peptidyl-prolyl isomerase Pin1 catalyzes the isomerization of the peptide bond preceding a proline residue between cis and trans isomers. To best understand the mechanisms of Pin1 regulation, rigorous enzymatic assays of isomerization are required. However, most measures of isomerase activity require significant constraints on substrate sequence and only yield rate constants for the cis isomer,
kcatcis and apparent Michaelis constants,
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Thermodynamic and NMR analysis of inhibitor binding to dihydrofolate reductase.
Thermodynamic and NMR analysis of inhibitor binding to dihydrofolate reductase.
Thermodynamic and NMR analysis of inhibitor binding to dihydrofolate reductase.
Bioorg Med Chem. 2010 Dec 15;18(24):8485-92
Authors: Batruch I, Javasky E, Brown ED, Organ MG, Johnson PE
Isothermal titration calorimetry (ITC) was used to determine the thermodynamic driving force for inhibitor binding to the enzyme dihydrofolate reductase (DHFR) from Escherichia coli. 1,4-Bis-{sulfanylmethyl}-3,6-dimethyl-benzene (1) binds DHFR:NADPH with a K(d) of 13±5 nM while the...
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Hydrodynamic dispersion in [Formula: see text] -lactoglobulin gels measured by PGSE NMR.
Hydrodynamic dispersion in -lactoglobulin gels measured by PGSE NMR.
Hydrodynamic dispersion in -lactoglobulin gels measured by PGSE NMR.
Eur Phys J E Soft Matter. 2011 Feb;34(2):1-15
Authors: Fridjonsson EO, Bernin D, Seymour JD, Nydén M, Codd SL
The displacement scale dependent molecular dynamics of solvent water molecules flowing through -lactoglobulin gels are measured by pulse gradient spin echo (PGSE) nuclear magnetic resonance (NMR). Gels formed under different p H conditions generate structures which are characterized by magnetic...
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Industrial Postdoctoral Chemist( analytical, organic or polymer) | Avomeen Analytical Services
Industrial Postdoctoral Chemist( analytical, organic or polymer) | Avomeen Analytical Services
US - Ann Arbor Michigan, Ph.D. in Analytical, organic or polymer chemistry. Hands-on knowledge of following techniques Analytical instrumentation is preferred: FT-IR, NMR, GC, GC-MS, LC-MS, TGA, DSC, ICP, and SEM-EDS. Must be
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[NMR paper] Thermodynamic interpretation of protein dynamics from NMR relaxation measurements.
Thermodynamic interpretation of protein dynamics from NMR relaxation measurements.
Related Articles Thermodynamic interpretation of protein dynamics from NMR relaxation measurements.
Protein Pept Lett. 2005 Apr;12(3):235-40
Authors: Spyracopoulos L
Protein dynamics and thermodynamics can be characterized through measurements of relaxation rates of side chain (2)H and (13)C, and backbone (15)N nuclei using NMR spectroscopy. The rates reflect protein motions on timescales from picoseconds to milliseconds. Backbone and methyl side chain NMR...
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[NMR paper] Interpretation of 15N NMR relaxation data of globular proteins using hydrodynamic cal
Interpretation of 15N NMR relaxation data of globular proteins using hydrodynamic calculations with HYDRONMR.
Related Articles Interpretation of 15N NMR relaxation data of globular proteins using hydrodynamic calculations with HYDRONMR.
J Biomol NMR. 2002 Jun;23(2):139-50
Authors: Bernadó P, García de la Torre J, Pons M
HYDRONMR is an implementation of state of the art hydrodynamic modeling to calculate the spectral density functions for NH or C(alpha)-H vectors in a rigid protein structure starting from an atomic level representation. Thus...
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[NMR paper] Thermodynamic insights into proteins from NMR spin relaxation studies.
Thermodynamic insights into proteins from NMR spin relaxation studies.
Related Articles Thermodynamic insights into proteins from NMR spin relaxation studies.
Curr Opin Struct Biol. 2001 Oct;11(5):555-9
Authors: Spyracopoulos L, Sykes BD
NMR spin relaxation measurements of picosecond to nanosecond timescale backbone and sidechain fluctuations of protein molecules, and subsequent entropic interpretation yield interesting, but sometimes counterintuitive, insights into proteins. The stabilities of proteins and protein interactions are achieved...
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[NMR paper] Hydrodynamic radii of native and denatured proteins measured by pulse field gradient
Hydrodynamic radii of native and denatured proteins measured by pulse field gradient NMR techniques.
Related Articles Hydrodynamic radii of native and denatured proteins measured by pulse field gradient NMR techniques.
Biochemistry. 1999 Dec 14;38(50):16424-31
Authors: Wilkins DK, Grimshaw SB, Receveur V, Dobson CM, Jones JA, Smith LJ
Pulse field gradient NMR methods have been used to determine the effective hydrodynamic radii of a range of native and nonnative protein conformations. From these experimental data, empirical relationships...
Thermodynamic and hydrodynamic properties of human tropoelastin. Analytical ultracent
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