21 research outputs found
Conformational properties of N-acetyl-L-alanine N',N'-dimethylamide.
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
Conformational properties of N',N'-dimethylamides of N-acetyldehydroalanine and N-acetyl-(Z)-dehydropheny-alanine.
Conformational preferences of Ac-ΔAla-NMe2 and Ac-(Z)-ΔPhe-NMe2 were studied and compared with those of their monomethyl counterparts as well as with those of their saturated analogues. X-Ray data and energy calculations revealed a highly conservative conformation of the dehydro dimethylamides, which is located in a high-energy region of the Ramachandran map
Conformational investigation of α,β-dehydropeptides. XIII. Conformational properties of N-acetyl-α,β-dehydrovaline N',N'-dimethylamide.
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
Conformational Properties of Oxazole-Amino Acids: Effect of the Intramolecular N–H···N Hydrogen Bond
Oxazole ring occurs in numerous natural
peptides, but conformational
properties of the amino acid residue containing the oxazole ring in
place of the C-terminal amide bond are poorly recognized. A series
of model compounds constituted by the oxazole-amino acids occurring
in nature, that is, oxazole-alanine (l-Ala-Ozl), oxazole-dehydroalanine
(ΔAla-Ozl), and oxazole-dehydrobutyrine ((<i>Z</i>)-ΔAbu-Ozl), was investigated using theoretical calculations
supported by FTIR and NMR spectra and single-crystal X-ray diffraction.
It was found that the main feature of the studied oxazole-amino acids
is the stable conformation β2 with the torsion angles φ
and ψ of −150°, −10° for l-Ala-Ozl,
−180°, 0° for ΔAla-Ozl, and −120°,
0° for (<i>Z</i>)-ΔAbu-Ozl, respectively. The
conformation β2 is stabilized by the intramolecular N–H···N
hydrogen bond and predominates in the low polar environment. In the
case of the oxazole-dehydroamino acids, the π-electron conjugation
that is spread on the oxazole ring and C<sup>α</sup>C<sup>β</sup> double bond is an additional stabilizing interaction.
The tendency to adopt the conformation β2 clearly decreases
with increasing the polarity of environment, but still the oxazole-dehydroamino
acids are considered to be more rigid and resistant to conformational
changes
Oak Park Energy Efficiency & Carbon Reduction (Semester Unknown) IPRO 329: OakParkEnergyEfficiencyAndCarbonReductionIPRO329ProjectPlantF10_redacted
The overall purpose of the IPRO 329 team is to work with the Village of Oak Park in order to implement a strategic plan to educate Oak Park residents in making their homes more efficient and work toward a community wide reduction of energy and water usage. In doing so, we also hope to gain valuable experience in working in a team with members with varying degrees of experience and skills.Sponsorship: Oak ParkDeliverable
Oak Park Energy Efficiency & Carbon Reduction (Semester Unknown) IPRO 329: OakParkEnergyEfficiencyAndCarbonReductionIPRO329FinalReportF10
The overall purpose of the IPRO 329 team is to work with the Village of Oak Park in order to implement a strategic plan to educate Oak Park residents in making their homes more efficient and work toward a community wide reduction of energy and water usage. In doing so, we also hope to gain valuable experience in working in a team with members with varying degrees of experience and skills.Sponsorship: Oak ParkDeliverable
Oak Park Energy Efficiency & Carbon Reduction (Semester Unknown) IPRO 329: OakParkEnergyEfficiencyAndCarbonReductionIPRO329BrochureF10
The overall purpose of the IPRO 329 team is to work with the Village of Oak Park in order to implement a strategic plan to educate Oak Park residents in making their homes more efficient and work toward a community wide reduction of energy and water usage. In doing so, we also hope to gain valuable experience in working in a team with members with varying degrees of experience and skills.Sponsorship: Oak ParkDeliverable
Oak Park Energy Efficiency & Carbon Reduction (Semester Unknown) IPRO 329: OakParkEnergyEfficiencyAndCarbonReductionIPRO329MidTermPresentationF10
The overall purpose of the IPRO 329 team is to work with the Village of Oak Park in order to implement a strategic plan to educate Oak Park residents in making their homes more efficient and work toward a community wide reduction of energy and water usage. In doing so, we also hope to gain valuable experience in working in a team with members with varying degrees of experience and skills.Sponsorship: Oak ParkDeliverable
Oak Park Energy Efficiency & Carbon Reduction (Semester Unknown) IPRO 329: OakParkEnergyEfficiencyAndCarbonReductionIPRO329PosterF10
The overall purpose of the IPRO 329 team is to work with the Village of Oak Park in order to implement a strategic plan to educate Oak Park residents in making their homes more efficient and work toward a community wide reduction of energy and water usage. In doing so, we also hope to gain valuable experience in working in a team with members with varying degrees of experience and skills.Sponsorship: Oak ParkDeliverable
Oak Park Energy Efficiency & Carbon Reduction (Semester Unknown) IPRO 329
The overall purpose of the IPRO 329 team is to work with the Village of Oak Park in order to implement a strategic plan to educate Oak Park residents in making their homes more efficient and work toward a community wide reduction of energy and water usage. In doing so, we also hope to gain valuable experience in working in a team with members with varying degrees of experience and skills.Sponsorship: Oak ParkDeliverable