Table 1. Estimating the relative contribution of TCR/MHC contacts to the total TCR/pMHC interaction energy.

	ΔG°1	Totalcalc2	Totalexp3	MHC4	MHC (%)5
1G4/NYESO-9V-HLA-A2	−7.5 ± 0.12	−12.5 ± 1.12	−13 ± 0.21	−5.1 ± 0.17	41 ± 4, 39 ± 2
A6/TAX-HLA-A2	−8.26 ± 0.06	−13.26 ± 1.06	n.d.	−6.4 ± 0.18	48 ± 4
JM22/MP-HLA-A2	−7.2 ± 0.06	−12.2 ± 1.06	n.d.	−1.32 ± 0.17	11 ± 2
G10/GAG-HLA-A2	−6.93 ± 0.06	−11.93 ± 1.06	n.d.	−5.63 ± 0.16	47 ± 4

All data except the final column are in units of kcal.mol⁻¹.

¹The standard state binding energy (ΔG°) was calculated from the K_D using the relationship ΔG° = RTlnK_D, where K_D is expressed in M.

²The total TCR/pMHC interaction energy (Total_calc) was calculated from the relationship. Total_calc = ΔG°− association entropy. where the association entropy was assumed to 5 ± 1 kcal.mol⁻¹ at the standard state, and to be the same for all TCR/pMHC interactions¹⁶,²⁴,²⁵.

³The experimentally determined total TCR/pMHC interaction energy (Total_exp) for the 1G4 TCR was obtained by adding the contributions of the TCR/MHC and TCR/peptide determined in Figs 5A and 6, respectively. ‘n.d.’ not determined.

⁴The contribution of MHC side chain to the binding energy. Data from Fig. 5.

⁵The % contribution of MHC contacts to the total interaction energy. For the 1G4 TCR the two values shown for MHC (%) use Total_calc and Total_exp, respectively.