title: Application of SAIL phenylalanine and tyrosine with alternative isotope-labeling patterns for protein structure determination.
abstract: The extensive collection of NOE constraint data involving the aromatic ring signals is essential for accurate protein structure determination, although it is often hampered in practice by the pervasive signal overlapping and tight spin couplings for aromatic rings. We have prepared various types of stereo-array isotope labeled phenylalanines (epsilon- and zeta-SAIL Phe) and tyrosine (epsilon-SAIL Tyr) to overcome these problems (Torizawa et al. 2005), and proven that these SAIL amino acids provide dramatic spectral simplification and sensitivity enhancement for the aromatic ring NMR signals. In addition to these SAIL aromatic amino acids, we recently synthesized delta-SAIL Phe and delta-SAIL Tyr, which allow us to observe and assign delta-(13)C/(1)H signals very efficiently. Each of the various types of SAIL Phe and SAIL Tyr yields well-resolved resonances for the delta-, epsilon- or zeta-(13)C/(1)H signals, respectively, which can readily be assigned by simple and robust pulse sequences. Since the delta-, epsilon-, and zeta-proton signals of Phe/Tyr residues give rise to complementary NOE constraints, the concomitant use of various types of SAIL-Phe and SAIL-Tyr would generate more accurate protein structures, as compared to those obtained by using conventional uniformly (13)C, (15)N-double labeled proteins. We illustrated this with the case of an 18.2 kDa protein, Escherichia coli peptidyl-prolyl cis-trans isomerase b (EPPIb), and concluded that the combined use of zeta-SAIL Phe and epsilon-SAIL Tyr would be practically the best choice for protein structural determinations.
authors: Structural Biology Research Center, Nagoya University, Furo-cho, Chikusa-ku, Japan.
authors: Mitsuhiro
authors: M
authors: Takeda
authors: Akira M
authors: AM
authors: Ono
authors: Tsutomu
authors: T
authors: Terauchi
authors: Masatsune
authors: M
authors: Kainosho
mesh_terms: D002247:Carbon Isotopes / Q000737:chemistry; D029968:Escherichia coli Proteins / Q000737:chemistry; D007527:Isoenzymes / Q000737:chemistry; D007553:Isotope Labeling / Q000379:methods*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D019696:Peptidylprolyl Isomerase / Q000737:chemistry; D010649:Phenylalanine / Q000737:chemistry*; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D029968:Escherichia coli Proteins; D007527:Isoenzymes; D011506:Proteins; D014443:Tyrosine; D010649:Phenylalanine; C421208:peptidyl-prolyl cis-trans isomerase b; D019696:Peptidylprolyl Isomerase