Circular Dichroism Calculator

Calculate mean residue ellipticity and estimate protein secondary structure

Sample Parameters

Secondary Structure Analysis

Mean Residue Ellipticity

-16500000

deg cm² dmol⁻¹ residue⁻¹

Calculated Values

Mean Residue Weight110.0 Da
[θ]MRW-16500000

Secondary Structure Estimate

α-Helix74.4%
β-Sheet15.6%
Random Coil10.0%

Note

Secondary structure estimates are approximate. For accurate analysis, use specialized software like CDNN, K2D, or BeStSel with full spectral data.

About Circular Dichroism

Circular dichroism measures the differential absorption of left- and right-circularly polarized light. Key features:

  • α-helix: Negative bands at 222nm and 208nm, positive band at 193nm
  • β-sheet: Negative band at ~218nm, positive band at ~195nm
  • Random coil: Negative band near 198nm
  • Applications: Protein folding, stability, conformational changes

Formula: [θ]MRW = (θ × MRW) / (10 × c × l)