• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.155-165
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• 2006

The results of this study confirm that the availability of hemin influences the expression of selected membrane proteins of Porphyromonas gingivalis, Prevotella intermedia, and Prevotella nigrescens. A 30 kDa (heated 24 kDa) hemin-binding protein whose expression is hemin regulated was identified and purified in P. gingivalis. A strong hemin-binding function was found by LDS-PAGE and TMBZ staining when P. gingivalis cells were grown under hemin-limited conditions. A 50 kDa cell envelope associated protein, whose expression is hemin regulated, is considered to be a putative hemin binding protein from P. intermedia and P. nigrescens, respectively. N-terminal amino acid sequence analysis of CNBr-digested 24 kDa hemin binding protein from P. gingivalis revealed that this protein belongs to a new, so far undescribed hemin-binding class of proteins. N-terminal amino acid sequence of a 50 kDa putative hemin binding protein from P. intermedia was identical with Enolase from Streptococcus intermedia. Work is in progress to further characterize the molecular structure of these proteins.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.663-676
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• 1999

Porphyromonas gingivalis, a Gram negative, anaerobic, asaccharolytic rod, is one of the most frequently implicated pathogens in human periodontal disease and has a requirement for hemin for growth. A 30 kDa (heated 24 kDa) hemin-binding protein whose expression is both hemin and iron regulated has recently been purified and characterized in this oral pathogen. This study has identified a hemin-binding P. gingivalis protein by expression of a P. gingivalis genomic library in Escherichia coli, a bacterium which does not require or transport exogenous hemin. A library of genomic DNA fragments from P. gingivalis was constructed in plasmid pUC18, transformed into Escherichia coli strain $DH5{\alpha}$ , and screened for recombinant clones with hemin-binding activity by plating onto hemin-containing agar. Of approximately 10,000 recombinant E. coli colonies screened on LB-amp-hemin agar, 10 exhibited a clearly pigmented phenotype. Each clone contained various insert DNA. The Hind III fragment transferred to the T7 RNA polymerase/promoter expression vector system produced a sligltly smaller (21 kDa) protein, a precursor form, immunoreactive to the antibody against the 24 kDa protein, suggesting that the cloned DNA fragment probably carried an entire gene for the 24 kDa hemin-binding protein.

• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.351-360
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• 2002

In the study presented here, identification, purification, and partial characterization of a hemin-regulated protein in Prevotella nigrescens were carried out. The results of this study confirm that the availability of hemin influences the expression of a selected membrane protein as well as the growth rate of P. nigrescens ATCC 33563. The 50 kDa cell envelope associated protein, whose expression is hemin regulated, is considered to be a putative hemin-binding protein from P. nigrescens. Disulfide bonds were not present in this protein, and N'-terminal amino acid sequence analysis revealed that this protein belongs to a new, so far undescribed protein. The 50 kDa protein was found to be rich in hydrophilic amino acids, with glycine comprising approximately 60% of the total amino acids. The study described here is the first to identify, purify, and biochemically characterize a putative hemin-binding protein from P. nigrescens. Work is in progress to further characterize the molecular structure of this protein.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.304-310
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• 2006

Prevotella intermedia is one of the most frequently implicated pathogens in human periodontal disease and has a requirement for hemin for growth. This study has identified a hemin-binding P. intermedia protein by expression of a P. intermedia genomic library in Escherichia coli, a bacterium which does not require or transport exogenous hemin. The genomic library of P. intermedia was constructed into plasmid pUC18, transformed into Escherichia coli strain $DH5{\alpha}$, and screened for recombinant clones using heminbinding activity by plating onto hemin-containing agar. Approximately 5,000 recombinant E. coli colonies were screened onto LB-amp-hemin agar, single clone(pHem1) was exhibited a clearly pigmented phonotype. The 2.5kb insert DNA of pHem1 was determined by restriction enzyme mapping. Southern blot analysis of BamHI, BglII, EcoRI, HindIII and PstI-digested P. intermedia DNA indicated that single copy of the gene was present in the genome. Northern blot analysis revealed that the size of transcript was approximately 1.8 kb. The cloned gene contained a single ORF, consisting of approximately 850-residue amino acids. A BLAST search of the Institute for Genomic Research genes with similar nucleotide sequence revealed no significant similarity It needs further investigation to clarify the mechanisms of heme uptake in P. intermedia.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.265-270
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• 2019

Growing evidence suggests that mediating apoptotic cell death of ER stress plays an important role in pathological development of neurodegenerative diseases including Alzheimer's disease. The ethanol extract of Rodiola sacra (ERS) investigates whether ER stress protects neuroinvasive neuro-2A cells from homocysteine (Hcy) cell death and ER stress. In neuronal cells, Hcy markedly decreased the viability of the cells and induced the death of Annexin V-positive cells as confirmed by MTT assay. The Hcy cell viability and apoptotic loss pretreated with ERS were attenuated, and Hcy showed stress in the expression of C / EBP homologous protein, 78-kDa glucose regulatory protein and the junction of X-box binding protein-1 (xbp1) mRNA. ESR decreased Hcy-induced mRNA binding, GRP78 and CHOP cells induced Hcy-induced ER stress and apoptosis, and Western blotting revealed expression of heme oxygenase-1 and HO-1 enzyme activity Inhibition is indicative of therapeutic value for neurodegenerative diseases such as decreased cell death by hemin.

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.561-574
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• 2000

Poly-P has been used to prevent decomposition of foods and has been shown to have inhibitory effect on the growth of gram positive bacteria. The purpose of this study was to evaluate the effect of poly-P on the growth of Porphyromonas endodontalis, a gram negative obligate anaerobic rod, endodontopathic bacterium. P. endodontalis ATCC 35406 was in BHI broth containing hemin and vitamin K with or without poly-P. Inhibitory effect of each poly-P which was added at the beginning(lag phase) or during(exponential phase) the culture, MIC(minimum inhibitory concentration) was determined by measuring the optical density of the bacterial cell at 540nm. Viable cell counts were measured to determined whether poly-P has a bactericidal effect. Leakage of intracellular nucleotides from P. endodontalis was determined at 260nm and morphological change of P. endodontalis was observed under the TEM(transmission electron microscope). Binding of 32P-labeled poly-P to P. endodontalis was examined. SDS-polyacrylamide gel electrophoresis and zymography were performed to observe the changes in protein and enzyme profiles of P. endodontalis, respectively. The results from this study were as follows : 1. The minimal inhibitory concentration(MIC) of poly-P to P. endodontalis appeared to be 0.04~0.05%. 2. Poly-P added to the P. endodontalis culture during the exponential phase of P. endodontalis was as much effective as poly-P added at the begining of the culture, suggesting that the antibacterial effect of poly-P is not much dependent on the initial inoculum size of P. endodontalis. 3. Poly-P are bactericidal to P. endodontalis, demonstrating the decrease of the viable cell counts. 4. Intracellular nucleotide release from the P. endodontalis, was not increased in the presence of poly-P and was not reversed by the addition of divalent cations like $Ca^{2+}$ and $Mg^{2-}$. 5. Under the TEM, it was observed that fine electro-dense materials were prominent in the poly-P grown P. endodontalis, appearing locally in the cell, and the materials were more abundant and more dispersed in the cell as the incubation time with poly-P increased. In addition, highly electron dense granules accumulated in many poly-P grown cells, most of which were atypical in their shape. 6. Binding of 32P-labeled poly-P to P. endodontalis appeared to be 32.8 and 45.5 and 53.4% at 30 minutes, 1 hours and 2 hours, respectively. 7. In the presence of poly-P. the synthesis of proteins with apparent molecular masses of 25, 27, 35, 45 was lost or drastically decreased whereas expression of a protein with an apparent molecular mass of 75 was elevated. 8. Proteolytic activity of P. endodontalis was decreased by poly-P. The overall results suggest that use of poly-P may affect the growth of P. endodontalis, and the anti-bacterial activity of poly-P seems largely bactericidal. Changes in shape, protein expression, and proteolytic activity of P. endodontalis by poly-P may be directly and indirectly attributed to the antibacterial effect of poly-P. Further studies will be needed to confirm the effect of poly-P.