An efficient NMR approach for obtaining sequence‐specific resonance assignments of larger proteins based on multiple isotopic labeling

[摘要]

By simultaneously incorporating in a protein ¹³C-carbonyl- and ¹⁵N-labeled amino acids with different levels of enrichment, characteristic asymmetric doublet-like patterns are observed for ¹⁵N nuclei that are directly adjacent to the ¹³C₁-labeled residues, providing unambiguous identification of a large number of unique dipeptide fragments of the protein. Additional assignments and qualitative structural information can be obtained from such a selectively labeled protein by recording multiple bond correlation spectra. The procedure is demonstrated for the protein calmodulin, complexed with calcium.

[学科分类] 生物化学/生物物理

[关键词] Two-dimensional NMR;Isotopic labeling;Sequential assignment;Calmodulin;Central helix