Table 3.

rms Distances between Superimposed HuLys and Cα Atoms

HuLys		D1.3		Framework		CDR		Lysozyme
				Å		Å		Å
Liganded		Liganded		0.67		0.37		0.43
Free		Free		0.68		0.63		–
Liganded		Free		0.62		0.44		–

Distances were calculated between Cα atoms of each segment after superposition of those atoms. Each heavy chain and each light chain of the two HuLys molecules was superposed separately on the corresponding D1.3 chain. Each set of distances was separated into two lists, one containing framework residue distances and one containing CDR residue distances. Each entry in the Table was then calculated from the four (liganded HuLys) or two (free HuLys) corresponding lists of distances. Both liganded HuLys molecules in the crystallographic asymmetric unit were used in the calculation, but only one of the two free HuLys molecules was included because the CDRs of the heavy chain of the other are somewhat distorted by symmetry-related contacts. For lysozyme superpositions, the two lysozyme molecules of the HuLys complex were superposed on the D1.3 lysozyme. D1.3 structures used for comparison were obtained from the Brookhaven Protein Data Bank, and correspond to the accession numbers 1VFA (free Fv) and 1 VFB (Fv-lysozyme complex).