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1. The peroxidase activity of cytochrome b6f complex from spinach chloroplasts

Creator:
Chen, X. B., Hou, C., Li, L. B., and Kuang, T. Y.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, cytochrome b6f complex, guaiacol, heme-containing protein, hydrogen peroxide, and peroxidase activity
Language:
Multiple languages
Description:
The cytochrome b6f (Cyt b6f) complex, which functions as a plastoquinol-plastocyanin oxidoreductase and mediates the linear electron flow between photosystem II (PSII) and photosystem I (PSI) and the cyclic electron flow around PSI, was isolated from spinach (Spinacia oleracea L.) chloroplasts using n-octyl-β-D-glucopyranoside (β-OG). The preparation was also able to catalyze the peroxidase-like reaction in the presence of hydrogen peroxide (H2O2) and guaiacol. The optimal conditions for peroxidase activity of the preparation included: pH 3.6, ionic strength 0.1, and temperature 35°C. The apparent Michaelis constant (Km) values for H2O2 and guaiacol were 50 mM and 2 mM, respectively. The bimolecular rate constant (k obs) was about 26 M-1 s-1 and the turnover number (K cat) was about 60 min-1 (20 mM guaiacol, 100 mM sodium phosphate, pH 3.6, 25°C, [H2O2]<100mM). These parameters were similar to those of several other heme-containing proteins, such as myoglobin and Cyt c. and X. B. Chen ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Virus-induced changes in photosynthetic parameters and peroxidase isoenzyme contents in tomato (Solanum lycopersicum L.) plants

Creator:
Huseynova, I. M., Mirzayeva, S. M., Sultanova, N. F., Aliyeva, D. R., Mustafayev, N. Sh., and Aliyev, J. A.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
chlorofyl, karotenoidy, chlorophyll, carotenoids, tobamovirus, efektivita fotosystému II, tylakoidní membránové proteiny, peroxidace lipidů, peroxidázové aktivity, photosystem II efficiency, thylakoid membrane proteins, lipid peroxidation, peroxidase activity, 2, and 581
Language:
Multiple languages
Description:
Tomato samples were collected from the field of Absheron peninsula in Azerbaijan in order to evaluate the incidence of main Tobamoviruses. According to results of serological and molecular tests, Tomato mosaic virus (ToMV), Tobacco mosaic virus (TMV), and Pepper mild mottle virus (PMMoV) were detected as single and mixed infections (TMV + PMMoV; ToMV + PMMoV) in various tomato samples. It was found that Tobamovirus infection caused an increase in the content of malondialdehyde, alterations in the activities of peroxidase enzymes and quantitative and qualitative changes in their molecular isoforms. A comparison of thylakoid membrane polypeptides from virus-infected leaves indicated a decrease in the content of the thylakoid membrane polypeptides with molecular masses of 123, 55, 47, 33, 28-24, 17, and 15 kD. PSII efficiency and the content of chlorophylls (a and b) were significantly lower in the virus-infected leaves., I. M. Huseynova, S. M. Mirzayeva, N. F. Sultanova, D. R. Aliyeva, N. Sh. Mustafayev, J. A. Aliyev., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public