Antibody fragment Fv4155 bound to two closely related steroid hormones: the structural basis of fine specificity.
Trinh, C.H., Hemmington, S.D., Verhoeyen, M.E., Phillips, S.E.(1997) Structure 5: 937-948
- PubMed: 9261086 
- DOI: https://doi.org/10.1016/s0969-2126(97)00247-5
- Primary Citation of Related Structures:  
1BFV, 1CFV, 2BFV - PubMed Abstract: 
The concentration of steroid glucuronides in serial samples of early morning urine (EMU) can be used to predict the fertile period in the female menstrual cycle. The monoclonal antibody 4155 has been used as a convenient means of measuring the concentration of steroid glucuronides in EMU, as it specifically recognises the steroid hormone estrone beta-D-glucuronide (E3G), with very high affinity, and the closely related hormone estriol 3-(beta-d-glucuronide) (EI3G), with reduced affinity. Although 4115 binds these hormones with different affinities, EI3G differs from E3G only in the addition of a hydroxyl group and reduction of an adjacent carbonyl. To investigate the structural basis of this fine binding specificity, we have determined the crystal structures of the variable fragment (Fv) of 4155 in complex with each of these hormones.
Organizational Affiliation: 
Department of Biochemistry and Molecular Biology, University of Leeds, UK.