Structure and dynamic studies by NMR of the potent sweet protein monellin and a non‐sweet analog

FEBS Letters

Ariyoshi, Yasuo¹  Mizukoshi, Toshimi¹  Suzuki, Ei-ichiro¹  Kohmura, Masanori¹ 

[1] Central Research Laboratories, Ajinomoto Co. Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210, Japan

关键词: Monellin;    Solid-phase synthesis;    Active residue AspB7;    Selectively 15N-labeled monellin;    Model-free analysis;    Abbreviations for amino acids follow the recommendations of the IUPAC-IUB Joint Commission on Biochemical Nomenclature in Eur. J. Biochem.;    138 (1984) 9-37;    Abu;    l-2-aminobutylic acid;    Fmoc;    fluorenyl-9-methoxycarbonyl;    NMR;    nuclear magnetic resonance;    NOE;    nuclear Overhauser effect;    But;    tertiary butyl;    T1;    longitudinal relaxation times;    T2;    transverse relaxation times;    B7;    the seventh residue in the B-chain;   

DOI  :  10.1016/S0014-5793(97)00945-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Monellin, an intensely sweet protein and a non-sweet analog in which the Asp^B7 in monellin has been replaced with Abu^B7 were studied by NMR. The results of our investigations show that the 3-dimensional structure of these two proteins are very similar indicating that the lack of the β-carboxyl group in the Abu^B7 analog is responsible for the loss of sweet potency. Selectively labeled monellin was prepared by solid-phase peptide synthesis by incorporating ¹⁵N-labeled amino acids into 10 key positions including Asp^B7. The internal mobility of these 10 key residues in monellin was estimated by the method of model-free analyses and our NMR studies show that Asp^B7 is the most flexible of these 10 residues. The flexibility of the Asp^B7 side chain may be important for receptor binding.

【 授权许可】

Unknown