15N nuclear magnetic resonance studies of the B domain of Staphylococcal protein A: sequence specific assignments of the imide 15N resonances of the proline residues and the interaction with human immunoglobulin G

[摘要]

¹⁵N nuclear magnetic resonance (NMR) studies of the B domain (FB) of Staphylococcus protein A, which is uniformly labeled with ¹⁵N, are reported. The α CH(i)-¹⁵N(i) connectivity in the ¹H-¹⁵N HMBC spectrum and the ¹³C(i-1)-¹⁵N(i) spin coupling in the ¹⁵N spectrum of a ¹³C-, ¹⁵N-doubly labeled FB were used to establish the assignments of the imide ¹⁵N resonances for all the three Pro residues that exist in FB. Addition of human IgG caused a significant downfield shift of the Pro-39 resonance. This result is quite consistent with our previous suggestion that a significant conformation change is induced in the Ser-42-Ala-55 helical region of FB when it is bound to human IgG.

[学科分类] 生物化学/生物物理

[关键词] 15N-labeling;Proline residue;1H-15N HMBC;Double labeling;Recombinant B domain of protein A;Immunoglobulin G;FB;B domain of Staphylococcal protein A;Fc;C-terminal half of the heavy chain of immunoglobulin;HMBC;1H-detected heteronuclear multiple bond correlation spectroscopy;IgG;immunoglobulin G;DSS;2;2-dimethyl-2-silapentane-5-sulfonate;HMQC;1H-detected heteronuclear multiple quantum coherence spectroscopy;NMR;nuclear magnetic resonance