Rotatory properties of molecules containing two peptide groups: experimental and theoretical results

Nielsen, Eigil B.; Schellman, John A.

doi:10.1002/bip.360100911

Cited by 39 publications

(16 citation statements)

References 23 publications

(2 reference statements)

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“…The calculations were performed with the matrix technique developed by Schellman and co-workers. [14][15][16][17] This technique requires as input transition energies, strengths and directions of electric and magnetic transition dipoles, transition monopoles and quadrupoles, and static charges. The methods for derivation of these data have recently been summarized, 18 and the results for the rhodanine and benzene chromophores are shown in Table 3.…”

Section: Theoretical Calculations Of CD Spectramentioning

confidence: 99%

Diastereomers of 3-(S)-(1-phenylethyl)-5-methyl- and -5-phenylrhodanine: Crystal structures, conformations, and circular dichroism spectra

et al. 1997

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3‐(S)‐(1‐phenylethyl)‐5‐methyl‐ and 5‐phenyl‐rhodanine have been studied by single crystal X‐ray crystallography. The crystals of the 5‐methyl compound were shown to contain equal amounts of the 5‐(R) and 5‐(S) diastereomers, while the crystals of the 5‐phenyl compound only contain the 5‐(S) diastereomer. The UV and CD spectra of the 5‐H2 compound have been analyzed on the basis of CNDO/S calculations, and the CD spectrum has been reproduced by semiempirical calculations. The 5‐methyl diastereomers can be partly separated by chromatography on triacetylcellulose, and the CD spectra of the individual forms can be evaluated. The 5‐phenyl compound undergoes rapid epimerization in solution, and also for this compound the CD spectra of both forms can be evaluated. The contribution of the 5‐substituent follows Ripperger's sector rule for dithiocarbamates. Chirality 9:568–577, 1997. © 1997 Wiley‐Liss, Inc.

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Section: Theoretical Calculations Of CD Spectramentioning

confidence: 99%

Diastereomers of 3-(S)-(1-phenylethyl)-5-methyl- and -5-phenylrhodanine: Crystal structures, conformations, and circular dichroism spectra

et al. 1997

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“…The Coulomb potential, V, with vacuum dielectric constant couples the transition monopoles from interacting groups. Positions and values for the ground state and transition monopole charges for the peptide primary, secondary, and tertiary amide groups, and, tryptophan, tyrosine, phenylalanine, and histadine side chains were taken from the literature [74][75][76][77][78][79]. In addition, transition monopoles amplitudes for (0, 1 L b ) and (0, 1 L a ) in tryptophan, or (0, 1 L b ) in tyrosine, were normalized to reproduce the dipole strength we observed from N-acetyl-Ltryptophanamide (NATpA) or N-acetyl-L-tyrosineamide (NATrA) in aqueous buffer at pH 7 [71].…”

Section: Optical Spectroscopymentioning

confidence: 99%

Myosin dynamics on the millisecond time scale

Burghardt¹,

Hu²,

Ajtai³

2007

Biophysical Chemistry

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Myosin is a motor protein associating with actin and ATP. It translates along actin filaments against a force by transduction of free energy liberated with ATP hydrolysis. Various myosin crystal structures define time points during ATPase showing the protein undergoes large conformation change during transduction over a cycle with approximately 10 ms periodicity. The protein conformation trajectory between two intermediates in the cycle is surmised by non-equilibrium Monte Carlo simulation utilizing free-energy minimization. The trajectory shows myosin transduction of free energy to mechanical work giving evidence for: (i) a causal relationship between product release and work production in the native isoform that is correctly disrupted in a chemically modified protein, (ii) the molecular basis of ATP-sensitive tryptophan fluorescence enhancement and acrylamide quenching, (iii) an actin-binding site peptide containing the free-energy barrier to ATPase product release defining the rate limiting step and, (iv) a scenario for actin-activation of myosin ATPase.

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“…Positions and values of the ground state and transition monopole charges for the peptide primary, secondary, and tertiary amide groups were taken from the literature. 21 Observable (, *) transitions in the tyrosine side chain…”

Section: Optical Signal Calculationmentioning

confidence: 99%

Cation–π interaction in a folded polypeptide

et al. 2002

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Cationic and aromatic side chains from protein residues interact to stabilize tertiary structure. The stabilization energy originates in part from electrostatic attraction between the cation, and regions of high electron density in pi-orbitals of the aromatic group, leading to the name cation-pi interaction. The lysine and tyrosine containing peptide, N-acetyl-Pro-Pro-Lys-Tyr-Asp-Lys-NH(2), has near uv CD characteristic of tyrosine in a structured environment. Nuclear Overhauser effect (NOE), coupling constant, and ring current chemical shift constraints obtained with (1)H NMR confirm that the peptide (t6p) folds. Simulated annealing consistent with all NMR constraints produces a 40-structure ensemble for t6p with potential energies within one standard deviation of the lowest value observed. Calculated binding energies indicate that cation-pi and cation-phenolic OH interactions exists between the Lys3 and Tyr4 side chains in most of the structures. The t6p peptide in solution is a model for these interactions in a protein. A perturbing electric field from the cationic ground state charge intermingles the excited states of the aromatic group. This intermingling effect may provide a cation-pi signature effect in the tyrosine spectroscopy. The absorption and CD for the lowest energy electronic transitions of the tyrosine phenol were computed for the ensemble. Red-shifted peak energy and hypochromicity in the absorbance band, and decreasing rotational strength, correlates with increasing binding energy of the complex indicating the cation-pi spectroscopic signature. The ensemble average spectroscopic signature effects in t6p are small and in agreement with observation.

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Rotatory properties of molecules containing two peptide groups: experimental and theoretical results

Cited by 39 publications

References 23 publications

Diastereomers of 3-(S)-(1-phenylethyl)-5-methyl- and -5-phenylrhodanine: Crystal structures, conformations, and circular dichroism spectra

Diastereomers of 3-(S)-(1-phenylethyl)-5-methyl- and -5-phenylrhodanine: Crystal structures, conformations, and circular dichroism spectra

Myosin dynamics on the millisecond time scale

Cation–π interaction in a folded polypeptide

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