Antifreeze Proteins: Blocking Ice Crystal Growth (2D)

Ice-Water Interface

Undercooling ΔT (°C below 0°C) 0.60

AFGP concentration 40%

Binding-site density 18 sites

Attachment kinetics (speed) 1.0×

Click the interface to bind a protein · drag to pan · scroll to zoom.

Live Readouts

Bound proteins

Avg. spacing

— nm*

Thermal hysteresis gap (Tm − Tf)

0.00 °C

How it works

This is a simplified 1D cross-section of the same real mechanism as the 3D version: a flat ice-water boundary line instead of a closed crystal ring. Proteins bind to fixed x-positions along the interface. Between two bound proteins the boundary can only bulge forward as a locally curved bump, and the Kelvin/Gibbs–Thomson relation says a tighter curve (closer protein spacing) demands more undercooling before it can advance:

ΔT_local ≈ 2γ·Tm / (ρ·L·r_curve),   r_curve ≈ spacing / 2

Unlike simple colligative antifreeze (which lowers melting and freezing point by the same amount, leaving no gap), this curvature pinning leaves the bulk melting point at 0 °C while the ice can't resume growing until ΔT clears the local barrier — a genuine thermal hysteresis gap that grows with protein concentration.

Undercooling ΔT — bulk driving force for growth.
AFGP concentration — fraction of binding sites occupied along the line.
Binding-site density — how many discrete adsorption sites the interface offers.
Comparison mode — uniform colligative depression, flat interface, zero hysteresis gap.

*Illustrative units, scaled for visibility.

Drag to pan · scroll to zoom · click ice to bind

Ice (below front) Bound AFGP molecule