Circular Dichroism Spectrum Blender (2D)

Secondary-Structure Blend

Alpha helix 40%

Beta sheet 35%

Random coil 25%

Scan

Scan speed 1.0×

Live Readout

Wavelength

190.0 nm

CD signal

0.00 mdeg

Dominant band

—

How it works

Each secondary-structure motif has a genuine, distinct far-UV CD signature modeled as a sum of Gaussian peak/trough terms in wavelength (λ), a standard way of representing measured CD bands:

signal(λ) = Σ A_i · exp( −(λ − μ_i)² / (2σ_i²) )

Alpha helix: +38@192nm, −32@208nm, −28@222nm  (double minimum)
Beta sheet:  +20@198nm, −24@216nm             (single broad minimum)
Random coil: −40@198nm, +6@218nm              (strong low-λ trough)

The three sliders set the fractional content of each motif; they are normalized (divided by their sum) so the blend always represents 100% of a hypothetical protein, and the composite spectrum is the weighted sum of the three reference curves — the same superposition principle used to fit measured protein CD spectra to reference basis sets in real spectropolarimetry.

Ghost curve — the full 190-250 nm spectrum for the current blend, drawn faint.
Live trace — the portion already swept by the scan, drawn bright.
Drag on the graph — grab the marker to scrub the scan position by hand.

Alpha helix Beta sheet Random coil Composite (weighted)