Table 1.

TH and IRI activity of AFPs from nanoliter cryoscopy, sonocrystallization, and optical microscopy measurements

AFP	Ice crystal-binding plane	$T{H}_{nano}/\sqrt{C}$, °C⋅mM−1/2	$T{H}_{sono}/\sqrt{C}$, °C⋅mM−1/2	Ci, μM
rQAE	$\left\{10\overline{1}0\right\}$ primary prism and $\left\{20\overline{2}1\right\}$ pyramidal planes (39)	0.90	0.91	5.9
AFGP1–5	$\left\{10\overline{1}0\right\}$ primary prism planes (40, 41)	0.78	0.48	0.00091
MpAFP	prism and basal planes (42)	20.8	0.85	0.011
DAFP-1	prism and basal planes (43)	19.8	0.32	2.1
ssAFP1	$\left\{11\overline{2}0\right\}$ secondary prism planes (13)	0.57	0.13	n.d.
wfAFP1	$\left\{20\overline{2}1\right\}$ pyramidal planes (13)	0.48	0.07	5.8

The ratio $TH/\sqrt{C}$ is used as a quantitative measure of TH activity. It corresponds to the slope of the curve that describes TH as a function of the square root of the protein concentration as illustrated in Fig. 2C. C_i is the IRI efficacy and represents the inhibitor concentration determined from the inflection point of a curve of the recrystallization constant k_d vs. C_AFP (Fig. S7) (21, 22). The tabulated cryoscopy values are from this work for rQAE, AFGP_1–5, and DAFP-1 and from literature for wfAFP1 (44), MpAFP (45), and ssAFP1 (46). Boldfaced show the two AFPs with the highest measured activity for a particular activity assay.