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Phytochemistry, 2007
Five serine proteinase inhibitors (Mirabilis jalapa trypsin inhibitors, MJTI I and II and Spinaci... more Five serine proteinase inhibitors (Mirabilis jalapa trypsin inhibitors, MJTI I and II and Spinacia oleracea trypsin inhibitors, SOTI I, II, and III) from the garden four-o’clock (M. jalapa) and spinach (S. oleracea) seeds were isolated. The purification procedures included affinity chromatography on immobilized methylchymotrypsin in the presence of 5 M NaCl, ion exchange chromatography and/or preparative electrophoresis, and finally RP–HPLC on a C-18 column. The inhibitors, crosslinked by three disulfide bridges, are built of 35 to 37 amino-acid residues. Their primary structures differ from those of known trypsin inhibitors, but showed significant similarity to the antimicrobial peptides isolated from the seeds of M. jalapa (MJ-AMP1, MJ-AMP2), Mesembryanthemum crystallinum (AMP1), and Phytolacca americana (AMP-2 and PAFP-S) and from the hemolymph of Acrocinus longimanus (Alo-1, 2 and 3). The association equilibrium constants (Ka) with bovine β-trypsin for the inhibitors from M. jalapa (MJTI I and II) and S. oleracea (SOTI I–III) were found to be about 107 M−1. Fully active MJTI I and SOTI I were obtained by solid-phase peptide synthesis. The disulfide bridge pattern in both inhibitors (Cys1–Cys4, Cys2–Cys5 and Cys3–Cys6) was established after their digestion with thermolysin and proteinase K followed by the MALDI-TOF analysis.Five trypsin inhibitors from the ripe seeds of the garden four-o’clock and spinach were isolated. The primary structures and disulfide bridge pattern were established for natural and chemical synthesized inhibitors. There are probably representatives of a family of serine proteinase inhibitors.
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Acta Physiologiae Plantarum, 1999
Short-term treatment of potato tuber (Solanum tuberosum L.) discs with CdCl2 changed glutathione ... more Short-term treatment of potato tuber (Solanum tuberosum L.) discs with CdCl2 changed glutathione reductase (GR) activity depending on cadmium ions concentrations, kind of tuber and time of incubation. The increase of GR activity at 10 and 100 µmol·dcm−3 of CdCl2 solutions was marked in less resistant tissues of cv. Bintje after 24 hrs, and was slight in more resistant tissues of cv. Bzura after 72 hrs. At 1 mmol·dcm−3 concentration of CdCl2 rapid and total inactivation in both kind of tissues was observed, which disappeared after a few days. However this elevation was faster in more resistant tissues. These inhibition effects come from the inactivation process of GR by cadmium. The values of KI for cadmium and KM for GSSG of GR from potato tuber tissues indicated that enzyme from more resistant tissues possessed lower affinity to toxic metal and higher affinity to substrate.
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Phytochemistry, 2007
Five serine proteinase inhibitors (Mirabilis jalapa trypsin inhibitors, MJTI I and II and Spinaci... more Five serine proteinase inhibitors (Mirabilis jalapa trypsin inhibitors, MJTI I and II and Spinacia oleracea trypsin inhibitors, SOTI I, II, and III) from the garden four-o’clock (M. jalapa) and spinach (S. oleracea) seeds were isolated. The purification procedures included affinity chromatography on immobilized methylchymotrypsin in the presence of 5 M NaCl, ion exchange chromatography and/or preparative electrophoresis, and finally RP–HPLC on a C-18 column. The inhibitors, crosslinked by three disulfide bridges, are built of 35 to 37 amino-acid residues. Their primary structures differ from those of known trypsin inhibitors, but showed significant similarity to the antimicrobial peptides isolated from the seeds of M. jalapa (MJ-AMP1, MJ-AMP2), Mesembryanthemum crystallinum (AMP1), and Phytolacca americana (AMP-2 and PAFP-S) and from the hemolymph of Acrocinus longimanus (Alo-1, 2 and 3). The association equilibrium constants (Ka) with bovine β-trypsin for the inhibitors from M. jalapa (MJTI I and II) and S. oleracea (SOTI I–III) were found to be about 107 M−1. Fully active MJTI I and SOTI I were obtained by solid-phase peptide synthesis. The disulfide bridge pattern in both inhibitors (Cys1–Cys4, Cys2–Cys5 and Cys3–Cys6) was established after their digestion with thermolysin and proteinase K followed by the MALDI-TOF analysis.Five trypsin inhibitors from the ripe seeds of the garden four-o’clock and spinach were isolated. The primary structures and disulfide bridge pattern were established for natural and chemical synthesized inhibitors. There are probably representatives of a family of serine proteinase inhibitors.
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Acta Physiologiae Plantarum, 1999
Short-term treatment of potato tuber (Solanum tuberosum L.) discs with CdCl2 changed glutathione ... more Short-term treatment of potato tuber (Solanum tuberosum L.) discs with CdCl2 changed glutathione reductase (GR) activity depending on cadmium ions concentrations, kind of tuber and time of incubation. The increase of GR activity at 10 and 100 µmol·dcm−3 of CdCl2 solutions was marked in less resistant tissues of cv. Bintje after 24 hrs, and was slight in more resistant tissues of cv. Bzura after 72 hrs. At 1 mmol·dcm−3 concentration of CdCl2 rapid and total inactivation in both kind of tissues was observed, which disappeared after a few days. However this elevation was faster in more resistant tissues. These inhibition effects come from the inactivation process of GR by cadmium. The values of KI for cadmium and KM for GSSG of GR from potato tuber tissues indicated that enzyme from more resistant tissues possessed lower affinity to toxic metal and higher affinity to substrate.
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