Temat: Ab initio calculations - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Conformational properties of N-acetyl-L-alanine N',N'-dimethylamide.
Autorzy:: Siodłak, Dawid
Rzeszotarska, Barbara
Broda, Małgorzata
Powiązania:: https://bibliotekanauki.pl/articles/1043329.pdf
Data publikacji:: 2004
Wydawca:: Polskie Towarzystwo Biochemiczne
Tematy:: ab initio/DFT calculations
N-alkylpeptides
β-turns
alanine derivative
N',N'-dimethylamides
peptide design
Opis:: Ab initio/DFT analysis of the conformational properties of free Ac-Ala-NMe2 (N-acetyl-L-alanine-N',N'-dimethylamide) in terms of the N-H···O, N-H···N, C-H···O hydrogen bonds and Cδ+ = Oδ- dipole attractions was performed. The Ala residue combined with the C-terminal tertiary amide prefers an extended conformation and that characteristic of the (i + 1)th position of the βVIb turn. These can be easily remodelled into a structure compatible with the (i + 1)th position of the βII/βVIa turn. The residue has also the potential to adopt the conformation accommodated at both central positions of the βIII/βIII' turn or the (i + 1)th position of the βI/β'I turn.
Źródło:: Acta Biochimica Polonica; 2004, 51, 1; 137-143
0001-527X
Pojawia się w:: Acta Biochimica Polonica
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Conformational properties of N-acetyl-N-methyl-α,β-dehydroalanine N-methylamide
Autorzy:: Macedowska, Agnieszka
Siodłak, Dawid
Rzeszotarska, Barbara
Powiązania:: https://bibliotekanauki.pl/articles/1041296.pdf
Data publikacji:: 2006
Wydawca:: Polskie Towarzystwo Biochemiczne
Tematy:: ab initio/DFT calculations
N-alkylpeptides
cis-trans isomerisation
α,β-dehydroamino acids
peptide design
Opis:: The conformational properties of Ac-Δ(Me)Ala-NHMe (N-acetyl-N-methyl-α,β-dehydroalanine N'-methylamide), as the simplest model of N-methyl-α,β-dehydroamino acids, was examined with theoretical methods and in comparison with Ac-ΔAla-NHMe and Ac-ΔAla-NMe2. The N-terminal amide of the Δ(Me)Ala residue easily adopts the configuration cis and the torsion angles φ, ψ are highly flexible. The Δ(Me)Ala residue is a conformational flexibilizer as compared to the parent ΔAla, which is a conformational stiffener. This seems to be the reason why Δ(Me)Ala is found in small natural cyclic peptides, where it ensures the conformational flexibility necessary for biological action.
Źródło:: Acta Biochimica Polonica; 2006, 53, 1; 227-232
0001-527X
Pojawia się w:: Acta Biochimica Polonica
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Conformational investigation of α,β-dehydropeptides. XIII. Conformational properties of N-acetyl-α,β-dehydrovaline N',N'-dimethylamide.
Autorzy:: Siodłak, Dawid
Rzeszotarska, Barbara
Broda, Małgorzata
Kozioł, Anna
Kołodziejczyk, Edyta
Powiązania:: https://bibliotekanauki.pl/articles/1043332.pdf
Data publikacji:: 2004
Wydawca:: Polskie Towarzystwo Biochemiczne
Tematy:: ab initio/DFT calculations
N',N'-dimethylamides
X-ray crystallography
α,β-dehydroamino acids
peptide design
valine derivative
Opis:: The crystal structure of Ac-ΔVal-NMe2 (ΔVal = α,β-dehydrovaline) was determined by X-ray crystallography. The found angles φ = -60° and ψ = 125° correspond exactly to the respective values of the (i + 1)th residue in idealised β-turn II/VIa. Ab initio/DFT studies revealed that the molecule adopts the angle ψ restricted only to about |130°| and very readily attains the angle φ = about -50°. This is in line with its solid-state conformation. Taken together, these data suggest that the ΔVal residue combined with a C-terminal tertiary amide is a good candidate at the (i + 1)th position in a type II/VIa β-turn.
Źródło:: Acta Biochimica Polonica; 2004, 51, 1; 145-152
0001-527X
Pojawia się w:: Acta Biochimica Polonica
Dostawca treści:: Biblioteka Nauki

Artykuł

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