Research of Professor Shinsuke Fujiwara in School of Biological and Enviromental Sciences was supported by the funding from a Grant for 2025 Individual Special Research from Kwansei-Gakuin University.
This study was conducted by the research group of Prof. Shinsuke Fujiwara with support from an 2025 Individual Special Research Grant (Development of an Environmentally Friendly Agmatine Production System), aiming to develop an efficient and environmentally sustainable method for agmatine production. Agmatine is a functional compound known for its roles in preventing cognitive decline and enhancing muscle function, and it is produced by the decarboxylation of arginine. Since arginine solubility increases at higher temperatures, the use of thermostable enzymes is expected to improve reaction efficiency under high-substrate conditions. In this study, the arginine decarboxylase (ADC) gene from the hyperthermophilic archaeon Pyrobaculum calidifontis VA-1 was cloned and expressed in Escherichia coli. The recombinant protein accumulated as inclusion bodies, and was solubilized using guanidine hydrochloride, followed by refolding at high temperature. This process successfully restored enzymatic activity. Although the refolded enzyme was unstable at low temperature, glycerol addition effectively improved its stability. Future work will focus on enzyme immobilization and development of a high-temperature agmatine production system. This content was published in BBRC.