Highly Active Carbonic Anhydrase of the Thylakoid Lumen of .

The green unicellular algae contains 12-13 carbonic anhydrases (CAs). For a long time, the two closely related α-CAs of the periplasmic membrane CAH1 and CAH2 were considered to be the CAs with the highest CO hydration activity. The recombinant protein α-CA CAH3 (rCAH3) from the thylakoid lumen obtained in the present study showed more than three times higher activity compared to CAH1 and more than 11 times higher compared to previous studies with rCAH3.

CAH3 from : Unique Carbonic Anhydrase of the Thylakoid Lumen.

CAH3 is the only carbonic anhydrase (CA) present in the thylakoid lumen of the green algae . The monomer of the enzyme has a molecular weight of ~29.5 kDa with high CA activity.

Action of 2,6-Dichloro-1,4-benzoquinone on the O-Evolving Activity of Photosystem II in Cells with and without Cell Wall: Inhibitory Effect of Its Oxidized Form.

is a widely used object in studies on green algae concerning both photosynthesis aspects and possible biotechnological approaches. The measurement of the maximum O evolution by photosystem II (PSII) in living algal cells in the presence of artificial acceptors is one of the commonly used methods for determining the photosynthetic apparatus state or its change as compared to a control, parent strain, etc., because PSII is the most sensitive component of the thylakoid membrane.

Involvement of Carbonic Anhydrase CAH3 in the Structural and Functional Stabilization of the Water-Oxidizing Complex of Photosystem II from Chlamydomonas reinhardtii.

The involvement of carbonic anhydrases (CA) and CA activity in the functioning of photosystem II (PSII) has been studied for a long time and has been shown in many works. However, so far only for CAH3 from Chlamydomonas reinhardtii there is evidence for its association with the donor side of PSII, where the CA activity of CAH3 can influence the functioning of the water-oxidizing complex (WOC). Our results suggest that CAH3 is also involved in the organization of the native structure of WOC independently of its CA activity.

The Main Structural and Functional Characteristics of Photosystem-II-Enriched Membranes Isolated from Wild Type and Mutant .

Photosystem II (PSII)-enriched membranes retain the original PSII architecture in contrast to PSII cores or PSII supercomplexes, which are usually isolated from . Here, we present data that fully characterize the structural and functional properties of PSII complexes in isolated PSII-enriched membranes from . The preparations were isolated from wild-type (WT) and CAH3-deficient mutant as the influence of CAH3 on the PSII function was previously proposed.

Carbonic anhydrase CAH3 supports the activity of photosystem II under increased pH.

The lumenal carbonic anhydrase (CA) CAH3 from green alga Chlamydomonas reinhardtii is the only one CA identified so far in close association with the photosystem II (PSII) multi-subunit protein complex. It was proposed earlier, that CAH3 could facilitate the H removal from the active center of the PSII water-oxidizing complex (WOC) under the light, thereby increasing its activity. In the present work, using PSII enriched membranes from the wild type of C.