Table 2.

Apparent aggregation states, thermal denaturation values, and probe-occupied cavity volumes for GCN4-pLI and variants, along with surface areas and volumes for relevant amino acids.

			Cavity volume (Å3)e	Cavity volume (Å3)e
Peptide	Nagga	Tm (°C)c	1.4 Å probe radius	1.8 Å probe radius	Amino acid	Side chain nonpolar surface area (43) (Å2)	Side chain volume (37) (Å3)
GCN4-pLI	4.3	94d	20–40	0	Gly	47	~
L9G	4.1	64	tunnelf	220	Ala	86	26.3
L9G+IB	~	~	tunnelf	240	Ser	56	30.4
L9S	4.1	68	100	80	Thr	90	56.2
L9A	4.0	70	220	190	Ile	155	101.1
L9A+IB	~	~	tunnelf	210	Leu	164	100.8
L9T	4.0	95	~g	~g
L16G E20C	3.9	37	330	260
L16G E20C Y17H	3.7b	37	370	300
L23G	3.8	51	280	230
L23S	4.0	66	150	120
L23A	4.1	80	~ h	~h
L23T	4.0	84	~ h	~ h
I26G	5.0	75	~g	~g
I26S	4.7	78	tunnelf	520
I26A	4.3	88	200	110
I26T	4.2	87	80	0

^aApparent aggregation number as measured by SEC. Estimated errors are ± 0.1.

^b~20% of the sample eluted with an N_agg of 3.0.

^cThermal denaturation curves determined by CD in neutral solutions containing 1 M guanidinium hydrochloride. Estimated errors are ± 2 °C.

^dPerformed in 3 M guanidinium hydrochloride.

^eBased on the reported high resolution values of ~2.0 Å, we estimate errors in cavity volume to be ~15%.

^fThe cavity was not enclosed on all sides, creating a tunnel through the peptide assembly.

^gElectron density could not be modeled beyond the site of the cavity, preventing determination of the cavity volume.

^hCrystals were not obtained for this peptide.