A Density Functional Theory Study of N-15 Chemical Shielding Anisotropy Tensors in Peptides (CROSBI ID 483912)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | međunarodna recenzija
Podaci o odgovornosti
Smrečki, Vilko ; Mueller, Norbert
engleski
A Density Functional Theory Study of N-15 Chemical Shielding Anisotropy Tensors in Peptides
Chemical shielding (or shift) anisotropy (CSA) is attracting increasing scientific interest in particular in the context of structure determination of biomolecules. Current NMR techniques enable more accurate determination of larger numbers of CSA's not only in solid state NMR of powder protein samples, but also in liquid state NMR both in isotropic solution and in fluid partially oriented media. Renewed interest in cross-correlation phenomena involving CSA has arisen since these can be exploited to derive structural constraints, using their dependence on the angle theta spanned by the principal axes of the respective interaction tensors as (3*cos**2theta-1)/2. As a prerequisite to structural interpretation of experimental CSA values we used Density Functional Theory (DFT) calculations in order to quantitatively predict the influence of secondary structure (phi and psi angles) on CSA tensors. The DFT calculations were conducted using the Gaussian98 program package employing implemented methods, basis sets and approaches (e.g., the 6-311G(d, p) basis set for geometry optimization, as well as frequency calculation and 6-311++G(3df, 3pd) basis set for NMR parameters calculation). The Becke's three parameter hybrid functional using the Lee, Yang and Parr correlation functional (B3LYP) was employed in DFT calculation, while the gauge independence requirement for NMR parameter calculation was treated with the Gauge Invariant Atomic Orbital (GIAO) approach. The first molecular model used in the simulation of secondary structure elements was a capped dipeptide (Ac-Ala-Ala-NH2). The results of DFT simulations of N-15 CSA showing dependence on secondary protein structure will be presented.
DFT; N-15; NMR; CSA; peptides; secondary structure
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Podaci o prilogu
34-x.
2002.
objavljeno
Podaci o matičnoj publikaciji
Book of Abstracts (http://www.chemi.muni.cz/nmr/radek/nmrvaltice/abstr_2002.pdf)
Holik, Miroslav ; Marek, Radek
Brno: Faculty of Science, Masaryk University, Brno
Podaci o skupu
17th NMR Valtice, Central European NMR Discussion Groups
predavanje
08.04.2002-10.04.2002
Valtice, Češka Republika