• atoms
  • Macrocyclic stereocontrol refers to the directed outcome of a given intermolecular or intramolecular chemical reaction, generally an organic reaction, that is governed by the conformational or geometrical preference of a carbocyclic or heterocyclic ring, where the ring containing 8 or more atoms. (wikipedia.org)
  • peptoids
  • Our study focuses on the conformational investigation of novel alternating α,β-peptoids to develop improved peptidomimetic scaffolds. (diamond.ac.uk)
  • However, the conformational investigation of peptoids is complicated by their inherent flexibility due to the presence of tertiary amide bonds which are devoid of H-bonding donors. (diamond.ac.uk)
  • 5 As a result, interpretation of NMR spectra is generally complicated, and chiroptical techniques, such as circular dichroism, become essential tools for the conformational investigation of peptoids. (diamond.ac.uk)
  • Our research has focused on investigation of the conformational preference of novel α,β-peptoids, which are composed of alternating α- and β- peptoid residues. (diamond.ac.uk)
  • synthesis
  • Significantly, even small conformational preferences, such as those envisioned in floppy macrocycles, can profoundly influence the ground state of a given reaction, providing stereocontrol such as in the synthesis of miyakolide. (wikipedia.org)
  • molecular structure
  • 596. Subramanian E., Molecular structure of acid-proteases. (ximicat.com)
  • X-ray crystallography, neutron diffraction and electron diffraction can give molecular structure for crystalline solids based on the distance between nuclei and concentration of electron density. (wikipedia.org)
  • Molecular geometries are best determined at low temperature because at higher temperatures the molecular structure is averaged over more accessible geometries (see next section). (wikipedia.org)
  • Atomic and molecular structure. (ucalgary.ca)
  • It was only in 1918 when Ernst Mohr, based on the molecular structure of diamond that had recently been solved using the then very new technique of x-ray crystallography, was able to successfully argue that Sachse's chair was the pivotal motif. (wikipedia.org)
  • A cocaine analogue is a (usually) artificial construct of a novel chemical compound from (often the starting point of natural) cocaine's molecular structure, with the result product sufficiently similar to cocaine to display similarity in, but alteration to, its chemical function. (wikipedia.org)
  • proteins
  • 586. Zuckerkandl E., The appearance of new structures and functions in proteins during evolution. (ximicat.com)
  • To understand the functions of proteins at a molecular level, it is often necessary to determine their three-dimensional structure. (soscholar.com)
  • NMR spectroscopy, and dual polarisation interferometry to determine the structure of proteins. (soscholar.com)
  • Protein structures range in size from tens to several thousand residues Proteins are classified by their physical size as nanoparticles (definition: 1-100 nm). (soscholar.com)
  • Using CS-CHEMeleon, Δδ predicted versus experimentally determined secondary structures were compared for large datasets of membrane and non-membrane proteins as a function of RCCS dataset, Δδ threshold, nucleus, localized parameter averaging and secondary structure type. (springer.com)
  • The biological activity of natural peptides and proteins is related to their sequence composition as well as to their three dimensional structure. (diamond.ac.uk)
  • The exceptional conformational rigidity of proline affects the secondary structure of proteins near a proline residue and may account for proline's higher prevalence in the proteins of thermophilic organisms. (wikipedia.org)
  • Most notably, UV CD is used to investigate the secondary structure of proteins. (wikipedia.org)
  • Chemical
  • Biomolecular NMR spectroscopy frequently employs estimates of protein secondary structure using secondary chemical shift (Δδ) values, measured as the difference between experimental and random coil chemical shifts (RCCS). (springer.com)
  • Beger RD, Bolton PH (1997) Protein phi and psi dihedral restraints determined from multidimensional hypersurface correlations of backbone chemical shifts and their use in the determination of protein tertiary structures. (springer.com)
  • A continued analysis of the relationship between chemical structure and reactivity. (ucalgary.ca)
  • stability
  • The hydroxylation of proline by prolyl hydroxylase (or other additions of electron-withdrawing substituents such as fluorine) increases the conformational stability of collagen significantly. (wikipedia.org)
  • secondary
  • abnormal configuration of abnormal prion protein (that is, conformers) can induce change in the secondary and tertiary structure of normal prion protein to generate additional amounts of the abnormal protein. (thefreedictionary.com)
  • Two new RCCS sets are presented here, determined in dimethyl sulfoxide (DMSO) and chloroform:methanol:water (4:4:1 by volume) at 298 K. A web-based program, CS-CHEMeleon, has been implemented to determine the accuracy of secondary structure assessment by calculating and comparing Δδ values for various RCCS datasets. (springer.com)
  • Despite obvious RCCS variations between datasets, prediction of secondary structure was consistently similar. (springer.com)
  • Strikingly, predictive accuracy seems to be most dependent upon the type of secondary structure, with helices being the most accurately predicted by Δδ values using five different RCCS tables. (springer.com)
  • Protein secondary structure can be described in terms of the dihedral angles φ, ψ and ω of the protein backbone. (wikipedia.org)
  • Proline is also commonly found in turns (another kind of secondary structure), and aids in the formation of beta turns. (wikipedia.org)
  • Multiple prolines and/or hydroxyprolines in a row can create a polyproline helix, the predominant secondary structure in collagen. (wikipedia.org)
  • energy
  • In general, the substituents exhibit preferences for equatorial placement, except for the lowest energy structure (pseudo A-value of -0.3 kcal/mol in figure below) in which axial substitution is favored. (wikipedia.org)
  • Timing and energy are also factors in isomerism. (britannica.com)
  • bonds
  • In general, stereoisomers contain double bonds that cannot rotate, or they may contain ring structures, where the rotation of bonds is restricted or prevented. (wikipedia.org)
  • successfully
  • From the very early stages of structural studies of DNA by X-ray diffraction and biochemical means, molecular models such as the Watson-Crick nucleic acid double helix model were successfully employed to solve the 'puzzle' of DNA structure, and also find how the latter relates to its key functions in living cells. (wikipedia.org)
  • upon
  • 1. [a] Formulate two Zimmerman-Traxler transition structures for the reaction of benzaldehyde with the Z-enolate shown on the right: [b] Assuming that product selectivity will be based upon the relative energies of the two transition structures, predict the favored pathway. (coursehero.com)