Amino acid selective labeling and unlabeling for protein resonance assignments.
Structural characterization of proteins by NMR spectroscopy begins with the process of sequence specific resonance assignments in which the (1)H, (13)C and (15)N chemical shifts of all backbone and side-chain nuclei in the polypeptide are assigned. This process requires different isotope labeled forms of the protein together with specific experiments for establishing the sequential connectivity between the neighboring amino acid residues. In the case of spectral overlap, it is useful to identify spin systems corresponding to the different amino acid types selectively. With isotope labeling this can be achieved in two ways: (i) amino acid selective labeling or (ii) amino acid selective 'unlabeling'. This chapter describes both these methods with more emphasis on selective unlabeling describing the various practical aspects. The recent developments involving combinatorial selective labeling and unlabeling are also discussed.
NMR Research Centre, Indian Institute of Science, Bangalore, India.
Garima
G
Jaipuria
B
B
Krishnarjuna
Somnath
S
Mondal
Abhinav
A
Dubey
Hanudatta S
HS
Atreya
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods*; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*
D000596:Amino Acids; D011506:Proteins