Glutamate synthesis via photoreduction of NADP+ by photostable chlorophyllide coupled with polyethylene-glycol

✍ Scribed by Hideharu Asada; Tetsuji Itoh; Yoh Kodera; Ayako Matsushima; Misao Hiroto; Hiroyuki Nishimura; Yuji Inada

• Book ID: 101723463
• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 143 KB
• Volume: 76
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.1029

✦ Synopsis

Abstract

Chlorophyllide a was coupled with α‐(3‐aminopropyl)‐ω‐methoxypoly(oxyethylene) (PEG–NH~2~) to form a PEG–chlorophyllide conjugate through an acid–amide bond. The conjugate catalyzed the reduction of methylviologen in the presence of 2‐mercaptoethanol. It also catalyzed the photoreduction of NADP^+^ or NAD^+^ in the presence of ascorbate as an electron donor and ferredoxin‐NADP^+^ reductase as the coupling enzyme. Utilizing the reducing power of NADPH generated by PEG‐chlorophyllide conjugate under illumination, glutamate was synthesized from 2‐oxoglutarate and NH~4~^+^ in the presence of glutamate dehydrogenase. PEG‐chlorophyllide conjugate was quite stable toward light illumination compared with chlorophyll a. The increase in the molecular weight of PEG in the PEG‐chlorophyllide conjugates was accompanied by the enhancement of photostability of the conjugate and also by the increased solubility in the aqueous solution. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 76: 86–90, 2001.