NEWS

Amino Acid Shielding Surfaces

The following shielding surfaces were produced by using the Gaussian 98 program by Haihong Sun, Lori K. Sanders, and Eric Oldfield (Journal of the American Chemical Society, Volume 124, Number 19, Pages 5486-5495. (You will need to install Adobe Acrobat to view these results). If you need a quick CSA prediction go to Bob Havlin's friendly Shift Calculator

Alpha Carbon Shielding Tensor Results

Glycine

Alanine

Valine(Chi=180)

Isoleucine(Chi1=-60,Chi2=180)

Serine(Chi=62)

Threonine (Chi=60)

Arginine (Chi1=-67,Chi2=180,Chi3=180, Chi4=180)

Leucine (Chi1=-60, Chi2=180)

Cysteine (Chi1=-60)

Methionine (Chi1=-65,Chi2=-65,Chi3=-70)

Aspartic (Chi1=-70,Chi2=-15)

Asparagine (Chi1=-65,Chi2=-20)

Glutamic acid (Chi1=-60, Chi2=180, Chi3=-10)

Glutamine( Chi1=-60, Chi2=180, Chi3=-30)

Lysine (Chi1=-60, Chi2=180, Chi3=180, Chi4=180)

Histidine (Chi1=-65, Chi2=-70)

Tyrosine (Chi1=-65, Chi2=-85)

Phenylalanine (Chi1=-65, Chi2=-85)

Tryptophan (Chi1=-65, Chi2=95)

Proline ( C γ endo )

The definition in the table are as follows:

σ_aniso = σ₃₃ - 1/2 (σ₂₂ + σ₁₁)

Δσ* = σ_orth - σ_par

Ω = σ₃₃ - σ₁₁

α₁ = angle between σ₁₁ and C^α-H bond vector

α₂ = angle between σ₂₂ and C^α-H bond vector

α₃ = angle between σ₃₃ and C^α-H bond vector

β₁ = angle between σ₁₁ and C^α-N bond vector

β₂ = angle between σ₂₂ and C^α-N bond vector

β₃ = angle between σ₃₃ and C^α-N bond vector

γ₁ = angle between σ₁₁ and C^α-C^O bond vector

γ₂ = angle between σ₂₂ and C^α-C^O bond vector

γ₃ = angle between σ₃₃ and C^α-C^O bond vector

Some additional results on alternate conformations have been calculated using the Texas Program (P. Pulay, University of Arkansas) by R. H. Havlin, A.C. de Dios, J. G. Pearson, D. Laws, and E. Oldfield, supported by NIH grants HL-19481 and GM50694. CSA's can be calculated for a given φ , ψ by Shift Calculator.

Alanine

Valine(Chi=-60)
Valine(Chi=60)

Isoleucine(Chi1=-60,Chi2=-60)
Isoleucine(Chi1=-60,Chi2=60)

Threonine(Chi=180)
Threonine(Chi=-60)