This chapter has described a bioenergetic analysis of the interaction of sCD4 with an IgG1, and two IgG4derivatives of an anti-sCD4 MAb. The MAbs have identical VHand VLdomains but differ markedly in their CHand CLdomains, raising the question of whether their antigen-binding chemistries are altered. We find the sCD4-binding kinetics and thermodynamics of the MAbs are indistinguishable, which indicates rigorously that the molecular details of the binding interactions are the same. We also showed the importance of using multiple biophysical methods to define the binding model before the bioenergetics can be appropriately interpreted. Analysis of the binding thermodynamics and kinetics suggests conformational changes that might be coupled to sCD4 binding by these MAbs are small or absent.
ASJC Scopus subject areas
- Molecular Biology