Anti-PsbP | 23 kDa protein of the oxygen evolving complex (OEC) of PSII (anti-protein)

Synechococcus sp. PCC 7942

Application example

2 µg of total protein from Arabidopsis thaliana leaf (1)  Hordeum vulgare leaf (2),  Chlamydomonas reinhardtii total cell (3),  Synechococcus sp. 7942 total cell (4), all extracted with PEB (AS08 300) and separated on  4-12% NuPage (Invitrogen) LDS-PAGE and blotted 1h to PVDF. Blots were blocked immediately following transfer in 2%  blocking reagent in 20 mM Tris, 137 mM sodium chloride pH 7.6 with 0.1% (v/v) Tween-20 (TBS-T) for 1h at room temperature with agitation. Blots were incubated in the primary antibody at a dilution of 1: 10 000 for 1h at room temperature with agitation. The antibody solution was decanted and the blot was rinsed briefly twice, then washed once for 15 min and 3 times for 5 min in TBS-T at room temperature with agitation. Blots were incubated in secondary antibody (anti-rabbit IgG horse radish peroxidase conjugated) diluted to 1:50 000 in 2% blocking solution for 1h at room temperature with agitation. The blots were washed as above and developed for 5 min with chemiluminescent detection reagent according the manufacturers instructions. Images of the blots were obtained using a CCD imager (FluorSMax, Bio-Rad) and Quantity One software (Bio-Rad).

Load per well on cell extract of Pinus banksiana (Jack Pine) was 7 µg.

This antibody can be used as a loading control for Chlamydomonas reinhardtii while it not so suitable for higher plants as accumulation of these proteins might drop to 12.5-25 % of the WT level in mutants defective for PSII core (Schult et al. 2007).

PSII reaction centre components are  generating the redox potential required to drive highly oxidizing water splitting reaction. Four Mn atoms are present on a lumenal surface and form the catalyctic site          of the water-splitting reaction which is in close association with the 33 kDa (PsbO), 23 kDa (PsbP) and 17 kDa (PsbQ) extrinistic subunits of oxygen evolving complex OEC. A 33-kDa extrinsic protein is also termed the Mn-stabilizing protein (MSP), however recent evidences shown that it is C-terminal domain of PsbA (D1) protein which is involved in in the assembly and stabilization of the OEC.