The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Tohru Nakajima - One of the best experts on this subject based on the ideXlab platform.
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PREVENTION OF AMYLOID-LIKE DEPOSITION BY A SELECTIVE Prolyl Endopeptidase INHIBITOR, Y-29794, IN SENESCENCE-ACCELERATED MOUSE
The Journal of pharmacology and experimental therapeutics, 1997Co-Authors: Akira Kato, Atsushi Fukunari, Yoko Sakai, Tohru NakajimaAbstract:Our study was performed to assess the hypothesis that Prolyl Endopeptidase (PEP) would be functionally involved in the senescence-accelerated amyloid formation and that long-term inhibition of Prolyl Endopeptidase would suppress the progression of Aβ-like deposition in the hippocampus of the senescence-accelerated mouse (SAM). Granular structures of Aβ-LI were observed in the hippocampus and around cerebral microvessels of the SAM after immunohistochemical staining with specific anti-Aβ antibody. Repeated treatment of the SAM with Y-29794 (1, 10, 20 mg/kg, p.o.), a specific inhibitor of Prolyl Endopeptidase, significantly reduced the number and density of Aβ-positive granular structures in the hippocampus of the SAM, after digital image analysis with NIH Image software. Furthermore, the characteristic biphasic distribution of the digitized density of the granules was significantly modulated after the treatment with Y-29794. These results suggest that chronic treatment of the SAM with Y-29794, a nonpeptide inhibitor of Prolyl Endopeptidase, prevents the progression of Aβ-like deposition in the hippocampus of the SAM.
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colocalization of Prolyl Endopeptidase and amyloid β peptide in brains of senescence accelerated mouse
Neuroscience Letters, 1994Co-Authors: Atsushi Fukunari, Shoichi Ishiura, Tadashi Yoshimoto, Akira Kato, Yoko Sakai, Koichi Suzuki, Tohru NakajimaAbstract:Abstract Prolyl Endopeptidase-like immunoreactivity (PEP-LI) was detected and compared with amyloid β-peptide-like immunoreactivity (Aβ-LI) in the brains of senescence-accelerated mouse (SAM). Granular structures of PEP-LI in the hippocampus appeared progressively, and age- and strain-dependently to form deposits which distributed morphologically similar and closely to those of Aβ-LI. These results suggest that PEP has functional relevance to amyloidgenesis in brains of SAM.
Tadashi Yoshimoto - One of the best experts on this subject based on the ideXlab platform.
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Directed evolution to improve the thermostability of Prolyl Endopeptidase.
Journal of biochemistry, 2000Co-Authors: Hidefumi Uchiyama, Tadashi Yoshimoto, Tetsuya Inaoka, Toyomi Ohkuma-soyejima, Hiroko Togame, Yasuhiko Shibanaka, Toshio KokuboAbstract:Prolyl Endopeptidase is the only Endopeptidase that specifically cleaves peptides at proline residues. Although this unique specificity is advantageous for application in protein chemistry, the stability of the enzyme is lower than those of commonly used peptidases such as subtilisin and trypsin. Therefore, we attempted to apply a directed evolution system to improve the thermostability of the enzyme. First, an efficient expression system for the enzyme in Escherichia coli was established using the Prolyl Endopeptidase gene from Flavobacterium meningosepticum. Then, a method for screening thermostable variants was developed by combining heat treatment with active staining on membrane filters. Random mutagenesis by error-prone PCR and screening was repeated three times, and as a result the thermostability of the enzyme was increased step by step as the amino acid substitutions accumulated. The most thermostable mutant obtained after the third cycle, PEP-407, showed a half-life of 42 min at 60 degrees C, which was 60 times longer than that of the wild-type enzyme. The thermostable mutant was also more stable with a high concentration of glycerol, which is a necessary condition for in vitro amidation.
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Prolyl Endopeptidase from Sphingomonas capsulata: isolation and characterization of the enzyme and nucleotide sequence of the gene.
Archives of biochemistry and biophysics, 1998Co-Authors: Tsutomu Kabashima, Kiyoshi Ito, Mikio Fujii, Yang Meng, Tadashi YoshimotoAbstract:Abstract Prolyl Endopeptidase (Prolyl oligopeptidase, EC 3.4.21.26) was purified from Sphingomonas capsulata IFO 12533, and its gene was cloned and expressed in Escherichia coli. The recombinant enzyme was markedly inhibited by diisopropyl phosphofluoridate and hardly affected by SH reagents or metal chelators, similar to the native enzyme purified from S. capsulata. Nucleotide sequencing analysis revealed an open reading frame of 2169 bp, coding for a protein of 723 amino acids with a predicted molecular weight of 78,433. The amino acid sequence was 39.6, 45.3, 38.9, and 38.3% homologous to Flavobacterium meningosepticum, Aeromonas hydrophila, porcine brain, and human T cell Prolyl Endopeptidase, respectively. A region near the C-terminus and the region containing the putative catalytic triad residues were highly conserved. The enzyme was crystallized by the hanging drop vapor diffusion method, using ammonium sulfate as a precipitant.
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Prolyl Endopeptidase Inhibitors Derived from Actinomycetes
Bioscience biotechnology and biochemistry, 1997Co-Authors: Ken-ichi Kimura, Fumiko Kanou, Yasushi Yamashita, Tadashi Yoshimoto, Makoto YoshihamaAbstract:Four Prolyl Endopeptidase inhibitors isolated from actinomycetes, named propeptin, SNA-8073-B, staurosporine, and enduracidin were classified into 3 groups on the basis of their inhibition potency against Prolyl Endopeptidase from a bacterium (Flavobacterium) and a mammal (human placenta). Staurosporine inhibited the enzyme from Flavobacterium more strongly than that from human placenta. Enduracidin inhibited the enzyme from human placenta more strongly than that from Flavobacterium. Propeptin and SNA-8073-B, both new compounds, inhibited the enzymes from both origins to the same extent.
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Purification and characterization of a Prolyl Endopeptidase from Pseudomonas sp. KU-22
Journal of Fermentation and Bioengineering, 1997Co-Authors: Hiroshi Oyama, Tadashi Yoshimoto, Hideyuki Aoki, Makoto Amano, Eiichi Mizuki, Daisuke Tsuru, Sawao MuraoAbstract:Abstract We detected a Prolyl Endopeptidase (EC 3.4.21.26) in the cell-free extract of Pseudomonas sp. KU-22. The enzyme was purified approximately 2,000-fold by a series of column chromatographies. The molecular weight and isoelectric point of the purified enzyme were estimated to be 76,000 and pH 4.9, respectively. The enzyme was most active at 45°C and pH 8.0 with benzyloxycarbonyl- l -alanyl- l -alanyl- l -proline p -nitroanilide (Z-Ala-Ala-Pro-NphNO 2 ) as a substrate. Significant inhibition of the enzyme by DFP and Prolyl Endopeptidase-specific inhibitors was observed. Some properties noted, particularly pH stability, amino acid composition, and pI of the enzyme, are clearly different from those of other bacterial Prolyl Endopeptidases reported to date, indicating that the enzyme is a member of the microbial Prolyl Endopeptidase family.
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Cloning and expression of the cDNA encoding Prolyl oligopeptidase (Prolyl Endopeptidase) from bovine brain
Biological & pharmaceutical bulletin, 1997Co-Authors: Tadashi Yoshimoto, Kaori Miyazaki, Naoko Haraguchi, Ana Kitazono, Tsutomu Kabashima, Kiyoshi ItoAbstract:Prolyl oligopeptidase (EC 3.4.21.26, Prolyl Endopeptidase) cDNA from bovine brain was cloned by PCR, and the amplified fragment was used as a probe to screen the cDNA library from bovine brain. The obtained clone contained a 2.7 kb DNA fragment with an open reading frame of 2130 nucleotides, and encoded a protein of 710 amino acids with a deduced molecular weight of 80640 Da. The deduced amino acid sequence is 95, 94, 51 and 48% homologous to those of human T-cell, porcine brain, Aeromonas hydrophila, and Flavobacterium meningosepticum Prolyl Endopeptidases, respectively. The bovine brain Prolyl Endopeptidase-encoding cDNA was expressed using an expression vector bearing a tac promoter, with an approximate yield of 20 μg/ml of cell culture.
Atsushi Fukunari - One of the best experts on this subject based on the ideXlab platform.
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PREVENTION OF AMYLOID-LIKE DEPOSITION BY A SELECTIVE Prolyl Endopeptidase INHIBITOR, Y-29794, IN SENESCENCE-ACCELERATED MOUSE
The Journal of pharmacology and experimental therapeutics, 1997Co-Authors: Akira Kato, Atsushi Fukunari, Yoko Sakai, Tohru NakajimaAbstract:Our study was performed to assess the hypothesis that Prolyl Endopeptidase (PEP) would be functionally involved in the senescence-accelerated amyloid formation and that long-term inhibition of Prolyl Endopeptidase would suppress the progression of Aβ-like deposition in the hippocampus of the senescence-accelerated mouse (SAM). Granular structures of Aβ-LI were observed in the hippocampus and around cerebral microvessels of the SAM after immunohistochemical staining with specific anti-Aβ antibody. Repeated treatment of the SAM with Y-29794 (1, 10, 20 mg/kg, p.o.), a specific inhibitor of Prolyl Endopeptidase, significantly reduced the number and density of Aβ-positive granular structures in the hippocampus of the SAM, after digital image analysis with NIH Image software. Furthermore, the characteristic biphasic distribution of the digitized density of the granules was significantly modulated after the treatment with Y-29794. These results suggest that chronic treatment of the SAM with Y-29794, a nonpeptide inhibitor of Prolyl Endopeptidase, prevents the progression of Aβ-like deposition in the hippocampus of the SAM.
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colocalization of Prolyl Endopeptidase and amyloid β peptide in brains of senescence accelerated mouse
Neuroscience Letters, 1994Co-Authors: Atsushi Fukunari, Shoichi Ishiura, Tadashi Yoshimoto, Akira Kato, Yoko Sakai, Koichi Suzuki, Tohru NakajimaAbstract:Abstract Prolyl Endopeptidase-like immunoreactivity (PEP-LI) was detected and compared with amyloid β-peptide-like immunoreactivity (Aβ-LI) in the brains of senescence-accelerated mouse (SAM). Granular structures of PEP-LI in the hippocampus appeared progressively, and age- and strain-dependently to form deposits which distributed morphologically similar and closely to those of Aβ-LI. These results suggest that PEP has functional relevance to amyloidgenesis in brains of SAM.
Akira Kato - One of the best experts on this subject based on the ideXlab platform.
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PREVENTION OF AMYLOID-LIKE DEPOSITION BY A SELECTIVE Prolyl Endopeptidase INHIBITOR, Y-29794, IN SENESCENCE-ACCELERATED MOUSE
The Journal of pharmacology and experimental therapeutics, 1997Co-Authors: Akira Kato, Atsushi Fukunari, Yoko Sakai, Tohru NakajimaAbstract:Our study was performed to assess the hypothesis that Prolyl Endopeptidase (PEP) would be functionally involved in the senescence-accelerated amyloid formation and that long-term inhibition of Prolyl Endopeptidase would suppress the progression of Aβ-like deposition in the hippocampus of the senescence-accelerated mouse (SAM). Granular structures of Aβ-LI were observed in the hippocampus and around cerebral microvessels of the SAM after immunohistochemical staining with specific anti-Aβ antibody. Repeated treatment of the SAM with Y-29794 (1, 10, 20 mg/kg, p.o.), a specific inhibitor of Prolyl Endopeptidase, significantly reduced the number and density of Aβ-positive granular structures in the hippocampus of the SAM, after digital image analysis with NIH Image software. Furthermore, the characteristic biphasic distribution of the digitized density of the granules was significantly modulated after the treatment with Y-29794. These results suggest that chronic treatment of the SAM with Y-29794, a nonpeptide inhibitor of Prolyl Endopeptidase, prevents the progression of Aβ-like deposition in the hippocampus of the SAM.
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colocalization of Prolyl Endopeptidase and amyloid β peptide in brains of senescence accelerated mouse
Neuroscience Letters, 1994Co-Authors: Atsushi Fukunari, Shoichi Ishiura, Tadashi Yoshimoto, Akira Kato, Yoko Sakai, Koichi Suzuki, Tohru NakajimaAbstract:Abstract Prolyl Endopeptidase-like immunoreactivity (PEP-LI) was detected and compared with amyloid β-peptide-like immunoreactivity (Aβ-LI) in the brains of senescence-accelerated mouse (SAM). Granular structures of PEP-LI in the hippocampus appeared progressively, and age- and strain-dependently to form deposits which distributed morphologically similar and closely to those of Aβ-LI. These results suggest that PEP has functional relevance to amyloidgenesis in brains of SAM.
Yoko Sakai - One of the best experts on this subject based on the ideXlab platform.
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PREVENTION OF AMYLOID-LIKE DEPOSITION BY A SELECTIVE Prolyl Endopeptidase INHIBITOR, Y-29794, IN SENESCENCE-ACCELERATED MOUSE
The Journal of pharmacology and experimental therapeutics, 1997Co-Authors: Akira Kato, Atsushi Fukunari, Yoko Sakai, Tohru NakajimaAbstract:Our study was performed to assess the hypothesis that Prolyl Endopeptidase (PEP) would be functionally involved in the senescence-accelerated amyloid formation and that long-term inhibition of Prolyl Endopeptidase would suppress the progression of Aβ-like deposition in the hippocampus of the senescence-accelerated mouse (SAM). Granular structures of Aβ-LI were observed in the hippocampus and around cerebral microvessels of the SAM after immunohistochemical staining with specific anti-Aβ antibody. Repeated treatment of the SAM with Y-29794 (1, 10, 20 mg/kg, p.o.), a specific inhibitor of Prolyl Endopeptidase, significantly reduced the number and density of Aβ-positive granular structures in the hippocampus of the SAM, after digital image analysis with NIH Image software. Furthermore, the characteristic biphasic distribution of the digitized density of the granules was significantly modulated after the treatment with Y-29794. These results suggest that chronic treatment of the SAM with Y-29794, a nonpeptide inhibitor of Prolyl Endopeptidase, prevents the progression of Aβ-like deposition in the hippocampus of the SAM.
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colocalization of Prolyl Endopeptidase and amyloid β peptide in brains of senescence accelerated mouse
Neuroscience Letters, 1994Co-Authors: Atsushi Fukunari, Shoichi Ishiura, Tadashi Yoshimoto, Akira Kato, Yoko Sakai, Koichi Suzuki, Tohru NakajimaAbstract:Abstract Prolyl Endopeptidase-like immunoreactivity (PEP-LI) was detected and compared with amyloid β-peptide-like immunoreactivity (Aβ-LI) in the brains of senescence-accelerated mouse (SAM). Granular structures of PEP-LI in the hippocampus appeared progressively, and age- and strain-dependently to form deposits which distributed morphologically similar and closely to those of Aβ-LI. These results suggest that PEP has functional relevance to amyloidgenesis in brains of SAM.
