Continuous enzymatic production of peptide precursor in aqueous/organic biphasic medium

✍ Scribed by Yoshihiko Murakami; Tatsunori Yoshida; Shigemitsu Hayashi; Akira Hirata

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 205 KB
• Volume: 69
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(20000705)69:1<57::aid-bit7>3.0.co;2-j

✦ Synopsis

N-(benzyloxycarbonyl)-L-aspartic acid (Z-L-Asp) has generally been used as a carboxyl substrate for the enzymatic synthesis of a precursor of aspartame (synthetic sweetener); however, alternative inexpensive protection groups have been in demand for lowering the total cost of its industrial-scale production. A formyl group (F-) was found to be a more desirable protecting group for the N-terminus of amino acid derivatives due to its low cost of preparation, introduction, and removal. The yield of F-AspPheOMe (N-formyl-L-aspartyl-L-phe- nylalanine methylester), however, was found to be <10% in a conventional aqueous medium. We found that F-L-Asp and L-PheOMe were partitioned mainly to the aqueous phase in an aqueous/organic biphasic medium, whereas F-AspPheOMe partitioned to the organic phase, especially when some extracting agents were added. In this study, simultaneous operation of an enzymatic reaction and a product separation by liquid-liquid extraction was thus applied to the F-AspPheOMe synthesis. We succeeded in synthesizing F-AspPheOMe continuously in an aqueous/tributylphosphate (TBP) biphasic medium with >95% yield, which was about tenfold higher than that in an aqueous monophasic medium.