IDENTIFICATION OF HEME-CONTAINING BANDS IN PHOTOSYSTEM-2 SAMPLES (BBY-PARTICLES AND REACTION CENTER) AFTER ELECTROPHORESIS WITH GLYCOSIDE DETERGENTS

Two bands stained with tetramethylbenzidine (TMBZ) were observed in BBY-particles enriched in photosystem (PS) 2 after electrophoresis with octyl-beta-D-glucopyranoside and LiDS at 4-degrees-C. The bands were identified as cytochromes b6 and f from the corresponding complex. D1-protein of PS 2 reaction centre (RC) absorbing heme of cytochrome b559 after dissociation of the latter may contribute to the intensity of cytochrome f band stained with TMBZ. The D2- and D2-proteins of PS 2 RC and cytochrome f possess the same electrophoretic mobility in the short gels. There are two bands of D1-protein in PS 2 RC sample after electrophoresis with dodecyl-beta-D-maltoside and LiDS at 4-degrees-C. One of them with the highest electrophoretic mobility enriched in hemes has an advantage over the other two bands of D1- and D2-Proteins. These data account for the tight bond between D1-protein and cytochrome b559 in PS 2 RC. After electrophoresis under mild conditions (glycoside detergents+LiDS at 4-degrees-C) cytochrome b559 dissociated into subunits and hemes in BBY-particles and PS 2 RC.