TABLE 1.

Backbone structure and proline mutant analysis of antigenic domain D residues

Residue no.	Wild-type residue	Backbone angle (°)a		Backbone analysisa		Rosetta proline ΔΔGb
		Φ	Ψ	Pro	Pre-Pro
437	Trp	−73.66	−18.28	Yes	No	0.5
438	Leu	−59.18	−59.67	Yes	No	0.3
439	Ala	−59.14	−37.12	Yes	Yes	0
440	Gly	−56.62	−26.31	Yes	Yes	0.1
441	Leu	−68.3	−40.87	Yes	Yes	2.1
442	Phe	−80.55	−40.18	Yes	Yes	2.7
443	Tyr	−159.11	143.78	No	Yes	2.5
444	Gln	−110.46	128.63	No	Yes	2.2
445	His	−58.15	153.22	Yes	Yes	0

^aValues and proline backbone analysis were obtained from the Ramachandran plot analysis web server (https://zlab.umassmed.edu/bu/rama/) (54). Pre-Pro assessments correspond to preproline Ramachandran plot conformation for the backbone of the preceding residue. Unfavorable Pro or preproline conformations are noted in boldface.

^bPredicted binding energy change for proline epitope mutant to the HC84.26.5D HMAb, based on the X-ray structure of the complex (PDB code 4Z0X) and computational mutagenesis in Rosetta (55). Predicted destabilizing values (>0.5 in Rosetta energy units) are indicated in boldface.