The effects of Cl(-), Mn(2+), Ca(2+), and pH on extrinsic and intrinsic photosystem II carbonic anhydrase activity were compared. Under the conditions of our in vitro experiments, extrinsic CA activity, located on the OEC33 protein, was optimum at about 30 mM Cl(-), and strongly inhibited above this concentration. This enzyme is activated by Mn(2+) and stimulated somewhat by Ca(2+). The OEC33 showed dehydration activity that is optimum at pH 6 or below. In contrast, intrinsic CA activity found in the PSII complex after removal of extrinsic proteins was stimulated by Cl(-) up to 0.4 M. Ca(2+) appears to be the required cofactor, which implies that the location of the intrinsic CA activity is in the immediate vicinity of the CaMn(4) complex. Up to now, intrinsic CA has shown only hydration activity that is nearly pH independent.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bbabio.2006.12.011 | DOI Listing |
Plants (Basel)
December 2024
Institute of Basic Biological Problems, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", 142290 Pushchino, Russia.
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.
View Article and Find Full Text PDFCells
January 2024
Institute of Basic Biological Problems, FRC PSCBR RAS, 142290 Pushchino, Russia.
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.
View Article and Find Full Text PDFPlant Cell Physiol
February 2024
Maize Research Institute, College of Agronomy and Biotechnology, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
Carbonic anhydrase (CA) catalyzes the reversible CO2 hydration reaction that produces bicarbonate for phosphoenolpyruvate carboxylase (PEPC). This is the initial step for transmitting the CO2 signal in C4 photosynthesis. However, it remains unknown whether the maize (Zea mays L.
View Article and Find Full Text PDFPlants (Basel)
April 2023
Institute of Basic Biological Problems, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", 142290 Pushchino, Moscow Region, Russia.
The knockout of the gene encoding α-carbonic anhydrase 2 (α-CA2) in (Columbia) led to alterations in photosynthetic processes. The effective quantum yields of both photosystem II (PSII) and photosystem I (PSI) were higher in α-carbonic anhydrase 2 knockout plants (α-CA2-KO), and the reduction state of plastoquinone pool was lower than in wild type (WT). The electron transport rate in the isolated thylakoids measured with methyl viologen was higher in α-CA2-KO plants.
View Article and Find Full Text PDFPhotosynthetica
May 2023
Department of Plant Physiology, Faculty of Agrobiology and Food Resource, Slovak University of Agriculture, 94976 Nitra, Slovakia.
The study aims to understand the effect of UV exclusion and arbuscular mycorrhizal fungi (AMF) inoculation on the photosynthetic parameters of soybean. The study was conducted in nursery bags and plants were grown under iron mesh covered with UV cut-off filters. The plants grown under the exclusion of UV with AMF inoculation (I) showed higher photosynthetic pigments, carbonic anhydrase activity, reduced internal CO concentration, enhanced transpiration rate, and stomatal conductance as well as improved photosynthetic rate over uninoculated plants.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!