Abstract
In chloroplast stroma, thioredoxin (Trx) regulates various enzyme acitivities including chloroplast ATP synthase and the four Calvin cycle enzymes, FBPase, GAPDH, PRK and SBPase, via thiol-disulfide exchange reaction. This regulation system is known as thiol modulation. Two Trxs in stroma, named Trx-f and Trx-m, function for this redox regulation. On the process of the reduction of the target protein, a reduced form Trx exchanges the disulfide bond and di-thiols with the target proteins and gives the reduced form target proteins. We had developed a new method to capture the possible target proteins using mutant Trx-immobilized resin, and succeeded to identify a number of new target proteins for chloroplast Trx.
We next intended to study the redox regulation system in thylakoid lumen. HCF164 is a thioredoxin-like protein localized in thylakoid lumen. We analyzed biochemical property and redox regulation of HCF164, and surveyed the target proteins for HCF164 in thylakoids.
