Isolation and Characterization of Photosystem II of Porphyra yezoensis Ueda

2004 ◽  
Vol 36 (11) ◽  
pp. 780-785 ◽  
Author(s):  
Zheng-Quan Gao ◽  
Guang-Ce Wang ◽  
Cheng-Kui Tseng

Abstract The thylakoid membranes were isolated and purified from gametophyte of Porphyra yezoensis Ueda (P. yezoensis) by sucrose density gradient ultracentrifugation. After P. yezoensis gametophyte thylakoid membranes were solubilized with SDS, the photosystem II (PSII) particles were isolated and purified. The activity of PSII particles was determined with DCIP (2,6-dichloroindophenol) photoreduction reaction. The composition of purified PSII particles was detected by SDS-PAGE. As a result, seven proteins including 55 kD protein, 47 kD protein, 43 kD protein, 33 kD protein, 31 kD protein, 29 kD protein, and 18 kD protein were found. Compared with PSII particles of higher plants and other algae, they were identified as D1/D2 complex, CP47, CP43, 33 kD protein, D1, D2 and cyt c-550 respectively. Besides, other three new proteins of 20 kD, 16 kD and 14 kD respectively were found. Among these extrinsic proteins, the 16 kD and 14 kD proteins had not been reported previously, and the 20 kD protein was found for the first time in multicellular red algae.

2018 ◽  
Vol 132 ◽  
pp. 356-362 ◽  
Author(s):  
Andrea Trotta ◽  
Simone Barera ◽  
Francesco Marsano ◽  
Domenico Osella ◽  
Davide Musso ◽  
...  

2020 ◽  
Vol 64 (1) ◽  
pp. 153-164
Author(s):  
Mohammed M. Abdel-Monsef ◽  
Hind A. Zidan ◽  
Doaa A. Darwish ◽  
Hassan M. Masoud ◽  
Mohamed S. Helmy ◽  
...  

AbstractThe hyaluronidase enzyme has been used in many such fields of medicine as ophthalmology, orthopaedia, internal medicine, gynecology, surgery, oncology and dermatology. In this study, the hyaluronidase enzyme was purified and characterized for the first time from Egyptian bee venom homogeneously using DEAE-cellulose and Sephacryl S-300 columns. Bee venom hyaluronidase specific activity was 411.7 units/mg protein with 49.9% yield and 3.23-fold purification. The molecular weight of the purified bee venom hyaluronidase native form was 37 kDa. The purified enzyme was found homogeneous on native PAGE and SDS-PAGE, with two congruent subunits of 18.4 kDa and isoelectric point (pI) of 8.6–8.8. The enzyme was found to be stable over a wide range of temperature (20–60°C) and pH (4.5–6.5), and its optimum activity at 37°C, pH 5.4 and 0.15 M NaCl. Km for bee venom hyaluronidase was 0.029 mg/ml hyaluronic acid and its activity was elevated in presence of MgCl2 and ZnCl2 and lowered in presence of FeCl2. Heparin inhibited the hyaluronidase enzyme noncompetitively with a Ki value of 2.9 units heparin and one binding site on the enzyme molecule.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saleem Farooq ◽  
Ruqeya Nazir ◽  
Shabir Ahmad Ganai ◽  
Bashir Ahmad Ganai

AbstractAs an approach to the exploration of cold-active enzymes, in this study, we isolated a cold-active protease produced by psychrotrophic bacteria from glacial soils of Thajwas Glacier, Himalayas. The isolated strain BO1, identified as Bacillus pumilus, grew well within a temperature range of 4–30 °C. After its qualitative and quantitative screening, the cold-active protease (Apr-BO1) was purified. The Apr-BO1 had a molecular mass of 38 kDa and showed maximum (37.02 U/mg) specific activity at 20 °C, with casein as substrate. It was stable and active between the temperature range of 5–35 °C and pH 6.0–12.0, with an optimum temperature of 20 °C at pH 9.0. The Apr-BO1 had low Km value of 1.0 mg/ml and Vmax 10.0 µmol/ml/min. Moreover, it displayed better tolerance to organic solvents, surfactants, metal ions and reducing agents than most alkaline proteases. The results exhibited that it effectively removed the stains even in a cold wash and could be considered a decent detergent additive. Furthermore, through protein modelling, the structure of this protease was generated from template, subtilisin E of Bacillus subtilis (PDB ID: 3WHI), and different methods checked its quality. For the first time, this study reported the protein sequence for psychrotrophic Apr-BO1 and brought forth its novelty among other cold-active proteases.


2002 ◽  
Vol 68 (9) ◽  
pp. 4390-4398 ◽  
Author(s):  
S. A. F. T. van Hijum ◽  
G. H. van Geel-Schutten ◽  
H. Rahaoui ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.


Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 546
Author(s):  
Jie Pan ◽  
Ni-Na Wang ◽  
Xue-Jing Yin ◽  
Xiao-Ling Liang ◽  
Zhi-Peng Wang

Tannase plays a crucial role in many fields, such as the pharmaceutical industry, beverage processing, and brewing. Although many tannases derived from bacteria and fungi have been thoroughly studied, those with good pH stabilities are still less reported. In this work, a mangrove-derived yeast strain Rhodosporidium diobovatum Q95, capable of efficiently degrading tannin, was screened to induce tannase, which exhibited an activity of up to 26.4 U/mL after 48 h cultivation in the presence of 15 g/L tannic acid. The tannase coding gene TANRD was cloned and expressed in Yarrowia lipolytica. The activity of recombinant tannase (named TanRd) was as high as 27.3 U/mL. TanRd was purified by chromatography and analysed by SDS-PAGE, showing a molecular weight of 75.1 kDa. The specific activity of TanRd towards tannic acid was 676.4 U/mg. Its highest activity was obtained at 40 °C, with more than 70% of the activity observed at 25–60 °C. Furthermore, it possessed at least 60% of the activity in a broad pH range of 2.5–6.5. Notably, TanRd was excellently stable at a pH range from 3.0 to 8.0; over 65% of its maximum activity remained after incubation. Besides, the broad substrate specificity of TanRd to esters of gallic acid has attracted wide attention. In view of the above, tannase resources were developed from mangrove-derived yeasts for the first time in this study. This tannase can become a promising material in tannin biodegradation and gallic acid production.


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