1ieh
From Proteopedia
SOLUTION STRUCTURE OF A SOLUBLE SINGLE-DOMAIN ANTIBODY WITH HYDROPHOBIC RESIDUES TYPICAL OF A VL/VH INTERFACE
Overview
The three-dimensional structure of a llama single-domain antibody BrucD4-4 was established by use of solution NMR spectroscopy. BrucD4-4 has Val, Gly, Leu, and Trp residues at positions 37, 44, 45, and 47, which are considered to be a hallmark to distinguish llama VH from V(H)H fragments at the germline level. In contrast to the murine and human VHs, BrucD4-4 has sufficient solubility, is monomeric in solution, and displays high-quality NMR spectra characteristic of well-structured proteins. Amide proton/deuterium exchange and the (15)N relaxation data showed that BrucD4-4 has a classic protein structure with a well-packed core and comparatively mobile surface loops. The three-dimensional architecture of BrucD4-4 is analogous to that of VHs from murine and human F(v)s and camelid V(H)Hs with two pleated beta-sheets formed by four and five beta-strands. A canonical and undistorted beta-barrel exposes a number of hydrophobic residues into the solvent on the surface of the three-dimensional structure. The eight-residue H3 loop folds over the side chain of Val37 similarly to that in llama V(H)Hs; however, this interaction may be transient due to the H3 conformational flexibility. Overall, the surface characteristics of BrucD4-4 with respect to hydrophobicity appear to lie between the human VH domain from Fv Pot and the llama V(H)H fragment HC-V, which may explain its enhanced solubility allowing NMR structural analysis.
About this Structure
Full crystallographic information is available from OCA.
Reference
Solution structure of a llama single-domain antibody with hydrophobic residues typical of the VH/VL interface., Vranken W, Tolkatchev D, Xu P, Tanha J, Chen Z, Narang S, Ni F, Biochemistry. 2002 Jul 9;41(27):8570-9. PMID:12093273 Page seeded by OCA on Fri May 2 19:54:43 2008
