RECONSTITUTION PHOTOACTIVE YELLOW PROTEIN FROM APOPROTEIN AND P-COUMARIC ACID-DERIVATIVES

We report reconstitution of photoactive yellow protein (PYP) from apoP YP and p-coumaric acid derivatives, The addition of p-coumaric acid to the apoPYP sample did not result in the recovery of PYP. In contrast, yellow products were obtained by the addition of p-coumaryl thiopheny l ester or p-coumaric anhydride to the apoPYP sample, the absorption s pectra of which were indistinguishable from the spectrum of intact PYP . Our findings provide strong evidence that PYP has the p-coumaryl chr omophore. This reconstitution technique opens the way for further biop hysical studies of PYP using artificial chromophore analogs.