A rapid method to attain isotope labeled small soluble peptides for NMR studies.

A widely applicable strategy is presented for efficient and rapid production of small water soluble peptides expressed as fusion proteins with the immunoglobulin-binding domain of streptococcal protein G. A simple extraction and purification scheme that includes a protease cleavage step to release the target peptide is described. The yield of authentic target peptide exceeds 10 mg per liter of culture. Production of U-13C, 15N and highly deuterated U-13C, 15N isotope labeled peptide is demonstrated for the 11 residue S2 peptide, corresponding to the C-terminus of the alpha-subunit of transducin, and the coiled coil trimerization domain from cartilage matrix protein (CMPcc), respectively. Heteronuclear two-dimensional NMR spectra are used for initial peptide characterization.