A Method for site-selective deuteration of amino acids and the development of new biopolymer materials

柴崎 千枝; 上田 実咲*; 高田 慎一  ; 安達 基泰*; 阿久津 和宏*

Shibazaki, Chie; Ueda, Misaki*; Takata, Shinichi; Adachi, Motoyasu*; Akutsu, Kazuhiro*

The amino acids are the main components of proteins, and they are deeply involved in physiological functions such as metabolism and immunity. For example, oligo peptides consisting of 8 to 50 amino acid residues are being rapidly expanded in their use as fibers, films, and pharmaceuticals. Deuterated amino acids, where some hydrogen atoms (H) are replaced with deuterium (D), are applied in the elucidation of enzyme reaction mechanisms and protein structure analysis. Additionally, leveraging the fact that the C-D bond in deuterated compounds is stronger compared to the C-H bond, the deuteration is accelerating improvement of chemical stability. On the other hand, most amino acids in proteins have enantiomers (L-form and D-form). Natural amino acids are almost exclusively L-form, whereas it is known that some organisms utilize D-form amino acids. Contribution of the D-form should be less degradation compared to the L-form amino acids as a reason. Therefore, studying the properties of each deuterated enantiomer, which have not been thoroughly examined, will result in the development of new materials. We have considered that developing selective deuteration techniques for the alpha-position and side chains of amino acids using Pt/C and Pd/C catalyst at 100-200 degree and synthesizing polypeptides including deuterated amino acids can lead to the creation of novel functional molecules. Here, we found that a selective and efficient chemical synthesis method for deuterated amino acids (L-alanine), although the resulting deuterated compounds formed racemic mixtures (mixtures of L-form and D-form). Our next issue is separation the enantiomers of deuterated amino acids. Further, we have plans to synthesize and analyze the properties of deuterated peptides forward application to new functional materials.