• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.838-844
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• 2001

The enzyme Fuc aldolase from Methanococcus jannaschii that catalyzes the aldol condensation of DHAP and L-lactaldehyde to give fuculose-1-phosphate was inactivated by DEP. The inactivation was pseudo first-order in the enzyme and DEP, which was biphasic. A pseudo second-order rate constant of 120$M^{-1}min^{-1}$ was obtained at pH 6.0 and $25{\circ}C$. Quantifying the increase in absorbance at 240nm showed that four histidine residues per subunit were modified during the nearly complete inactivation. The statistical analysis and the time course of the modification suggested that two or three histidine residues were essential for activity. The rate of inactivation was dependent on the pH, and the pH inactivation data implied the involvement of the amino acid residue with a $pK_a$ value of 5.7. Fuc aldolase was protected against DEP inactivation by DHAP, indicating that the histidine residues were located at the active site of Fuc aldolase. DL-Glyceraldehyde, as an alternative substrate to L-lactaldehyde, showed no specific protection for the Fuc aldolase.

• Journal of Veterinary Science
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• v.21 no.1
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• pp.4.1-4.9
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• 2020

Fast and accurate detection of viral RNA pathogens is important in apiculture. A polymerase chain reaction (PCR)-based detection method has been developed, which is simple, specific, and sensitive. In this study, we rapidly (in 1 min) synthesized cDNA from the RNA of deformed wing virus (DWV)-infected bees (Apis mellifera), and then, within 10 min, amplified the target cDNA by ultra-rapid qPCR. The PCR products were hybridized to a DNA-chip for confirmation of target gene specificity. The results of this study suggest that our method might be a useful tool for detecting DWV, as well as for the diagnosis of RNA virus-mediated diseases on-site.

• Journal of Veterinary Clinics
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• v.40 no.4
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• pp.288-293
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• 2023

A 11-year-old neutered male Maltese dog was vaccinated with a rabies vaccine (Rabisin^®, Boehringer Ingelheim International GmbH, Germany) subcutaneously at a local animal hospital. One hour after vaccination, purpura with edema was observed at the injection site and severe thrombocytopenia (0 K/μL) was noted on a complete blood count (CBC). No specific findings were found in serum chemistry, electrolyte, blood gas analysis, and coagulation tests. The patient was hospitalized and administered antihemorrhagic agents (vitamin K, desmopressin), antihistamines (chlorpheniramine) and corticosteroids (methylprednisolone sodium succinate). On a repeat CBC, mild anemia had developed, thrombocytopenia was still noted, and autoagglutination was observed on a saline agglutination test (SAT). A polymerase chain reaction panel for infectious agents (e.g., Babesia spp.) was negative. The diagnosis was secondary immune-mediated thrombocytopenia (IMT) with immune-mediated hemolytic anemia (IMHA) associated with vaccination. Therefore, the immunosuppressants (prednisolone, and mycophenolate mofetil) were administered. Six days after drug administration, new lesion was not observed, and the previous lesions were significantly improved. It gradually improved and 4 weeks after hematocrit and platelet recovered to normal levels. It was maintained for 6 months without recurrence of related symptoms. Based on patient's history and test results, the patient was diagnosed with Evans' syndrome associated with rabies vaccine.

• Analytical Science and Technology
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• v.10 no.5
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• pp.378-385
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• 1997

In order to clarify the functional role of Tyr7 in human glutathione S-transferase P1-1, we extensively investigated the effect of mutation of Tyr7 on the substrate specificity and inhibition characteristics. The mutational replacement of Tyr7 with phenylalanine lowered the specific activities with 1,2-dichloro-4-nitrobenzene and 1,2-epoxy-3-(p-nitrophenoxy) propane for GSH-conjugation reaction to 3~5% of the values for the wild-type enzyme. The pKa of the thiol group of GSH bound in Y7F was about 2.4 pK units higher than that in the wild-type enzyme. The $I_{50}$ of hematin for Y7F was similar to that for the wild-type enzyme and those of benastatin A and S-(2,4-dinitrophenyl)glutathione were only moderately decreased. These results suggest that Tyr7 is considered to be important the catalytic activities not only for GSH-chloronitrobenzene derivatives but also for GSH-epoxide conjugation reaction, rather than to binding of the substrates.

• Journal of Ginseng Research
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• v.34 no.1
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• pp.41-46
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• 2010

Expensive herbs such as ginseng are always a possible target for fraudulent labeling. New mountain ginseng strains have occasionally been found deep within mountain areas and commercially traded at exorbitant prices. However, until now, no scientific basis has existed to distinguish such ginseng from commonly cultivated ginseng species other than by virtue of being found within deep mountain areas. Polymerase chain reaction (PCR) analysis of the internal transcribed spacer has been shown to be an appropriate method for the identification of the most popular species (Panax ginseng) in the Panax ginseng genus. A single nucleotide polymorphism (SNP) has been identified between three newly found mountain ginseng (KGD4, KGD5, and KW1) and already established Panax species. Specific PCR primers were designed from this SNP site within the sequence data and used to detect the mountain ginseng strains via multiplex PCR. The established multiplex-PCR method for the simultaneous detection of newly found mountain ginseng strains, Korean ginseng, and foreign ginseng in a single reaction was determined to be effective. This study is the first report of scientific discrimination of "mountain ginsengs" and describes an effective method of identification for fraud prevention and for uncovering the possible presence of other, cheaper ginseng species on the market.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.11-24
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• 2002

The antitumor antibiotic (+)-CC-1065 can alkylate N3 of guanine in certain sequences. A previous high-field $^1H$ NMR study on the$(+)-CC-1065d[GCGCAATTG*CGC]_2$ adduct ($^*$ indicates the drug alkylation site) showed that drag modification on N3 of guanine results in protonation of the cross-strand cytosine [Park, H-J.; Hurley, L. H. J. Am. Chem. Soc.1997, 119,629]. In this contribution we describe a further analysis of the NMR data sets together with restrained molecular dynamics. This study provides not only a solution structure of the (+)-CC-1065(N3- guanine) DNA duplex adduct but also new insight into the molecular basis for the sequence- specific interaction between (+)-CC-1065 and N3-guanine in the DNA duplex. On the basis of NOESY data, we propose that the narrow minor groove at the 7T8T step and conformational kinks at the junctions of 16C17A and 18A19T are both related to DNA bending in the drugDNA adduct. Analysis of the one-dimensional $^1H$ NMR (in $H_2O$) data and rMD trajectories strongly suggests that hydrogen bonding linkages between the 8-OH group of the (+)-CC-1065 A-sub-unit and the 9G10C phosphate via a water molecule are present. All the phenomena observed here in the (+)-CC-1065(N3-guanine) adduct at 5'$-AATTG^*$are reminiscent of those obtained from the studies on the (+)-CC-1065(N3-adenine) adduct at $5'-AGTTA^*$, suggesting that (+)-CC-1065 takes advantage of the conformational flexibility of the 5'-TPu step to entrap the bent structure required for the covalent bonding reaction. This study reveals a common molecular basis for (+)-CC-1065 alkylation at both $5'-TTG^*$ and $5'-TTA^*$, which involves a trapping out of sequence-dependent DNA conformational flexibility as well as sequence-dependent general acid and general base catalysis by duplex DNA.

• The Korean Journal of Physiology
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• v.15 no.2
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• pp.73-81
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• 1981

Experiments were conducted in ischemic decerebrate cats to study the effects of electroacupuncture and electrical stimulation of peripheral nerve on pain reaction. Flexion reflex was used as an index of pain. The reflex was elicited by stimulating the sural nerve(20 V, 0.5 msec duration) and recorded as a compound action potential from the nerve innervated to the semitendinosus muscle. Electroacupuncture was performed, using a 23-gauge hyperdermic needle, on the tsusanli point in the lateral upper tibia of the ipsilateral hindlimb. The common peroneal nerve was selected as a peripheral nerve which may be associated with electroacupuncture action, as it runs through the tissue portion under the tsusanli point. Both for electroacupuncture and the stimulation of common peroneal nerve a stimulus of 20 V-intensity, 2 msec-duration and 2 Hz-frequency was applied for 60 min. The results are summerized as follows: 1) The electroacupuncture markedly depressed the flexion reflex; this effect was eliminated by systemic application of naloxone $(0.02{\sim}0.12\;mg/kg)$, a specific narcotic antagonist. 2) Similarly, the electrical stimulation of the common peroneal nerve significantly depressed the flexion reflex, the effect being reversed by naloxone. 3) When most of the afferent nerves excluding sural nerve in the ipsilateral hindlimb were cut, the effect of electroacupuncture on the flexion reflex was not observed. Whereas direct stimulation of the common peroneal nerve at the proximal end from the cut resulted in a significant reduction of the flexion reflex, again the effect was reversible by naloxone application. 4) Transection of the spinal cord at the thoracic 12 did not eliminate the effect of peripheral nerve stimulation on the flexion reflex and its reversal by naloxone, although the effect was significantly less than that in the animal with spinal cord intact. These results suggest that: 1) the analgesic effect of an electroacupuncture is directly mediated by the nervous system and involves morphine-like substances in CNS, 2) the site of analgesic action of electroacupuncture resides mainly in the brainstem and in part in the spinal cord.

• Advances in nano research
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• v.16 no.1
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• pp.41-52
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• 2024

In this study, rare-earth orthoferrites LnFeO₃ were synthesized using a facile hydrothermal reaction and their visible-light-induced photo-Fenton degradation of organics was optimized through Ln variation (Ln = La, Pr, or Gd). The morphological, structural, and chemical characteristics of as-prepared samples were examined in detail by using different methods, including XRD, SEM, TEM, XPS, etc. On the other side, under visible light illumination, the photo-Fenton-like catalytic activities of LnFeO₃ were assessed in terms of the removal of selected organic models, i.e., pharmaceuticals (ketoprofen and tetracycline) and dyes (rhodamine B and methyl orange). As compared with PrFeO₃ or GdFeO₃, the sample of LaFeO₃ displayed more structural distortion, larger specific surface area, and narrower band gap, resulting in its higher photo-Fenton-like catalytic activity toward the degradation of organics. In organic-containing solution, in which the initial solution pH = 5, catalyst dosage = 1 g/L and H₂O₂ concentration = 10 mM, 98.2% of rhodamine B, 31.1% of methyl orange, 67.7% of ketoprofen, or 96.4% of tetracycline was removed after 90-min exposure to simulated visible light. Our findings revealed that variation of Ln site on rare-earth orthoferrites was an effective strategy for optimizing their organic removal via visible-light-induced photo-Fenton reaction.

• Microbiology and Biotechnology Letters
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• v.16 no.3
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• pp.238-245
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• 1988

Studies were made on the regulation of chorismate mutase and prephenate dehydratase of a species of Intrasporangium, a phenylalanine producing Actinomycete isolated from soil. Two distinctly regulated species of chorismate mutase, designated CM I and CM IIwere resolved by DEAE Cellulose and DEAE Sephadex A 50 chromatography. The activity of CM II was inhibited by L-tyrosine, whereas that of CM I appeared to be unregulated. Single species of prephenate dehydyatase was also separated in the same purification steps. The activity of the enzyme was strongly feedback inhibited by L-phenylalanine, but by L-tyrosine or L-methionine it was rather slightly stimulated. Synthesis of chorismate mutase was not influenced by the presence of phenylalanine, tyrosine or tryptophan, whereas prephenate dehydratase was found to be subject to strong feedback repression by L-phenylalanine. The rate of repression was 94% at the concentration of 1mM L-phenylalanine but the repression was completely offset by the presence of 5mM tyrosine. The critical regulatory site of the phenylalanine terminal biopathway was, therefore, proved to be the second reaction which was catalyzed by the L-phenylalanine inhibitable and repressible prephenate dehydratase.

• BMB Reports
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• v.36 no.4
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• pp.409-416
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• 2003

The isoform 1 of cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) from Paenibacillus sp. A11 was purified by a preparative gel electrophoresis. The importance of histidine, tryptophan, tyrosine, and carboxylic amino acids for isoform 1 activity is suggested by the modification of the isoform 1 with various group-specific reagents. Activity loss, when incubated with diethylpyrocarbonate (DEP), a histidine modifying reagent, could be protected by adding 25 mM methyl-$\beta$-cyclodextrin substrate prior to the modification. Inactivation kinetics of isoform 1 with DEP resulted in second-order rate constants ($k_{inactivation}$) of $29.5\;M^{-1}s^{-1}$. The specificity of the DEP-modified reaction for the histidine residue was shown by the correlation between the loss of isoform activity and the increase in the absorbance at 246 nm of N-carbethoxyhistidine. The number of histidines that were modified by DEP in the absence and presence of a protective substrate was estimated from the increase in the absorbance using a specific extinction coefficient of N-carbethoxyhistidine of $3,200\;M^{-1}cm^{-1}$. It was discovered that methyl-$\beta$-CD protected per mole of isoform 1, two histidine residues from the modification by DEP. To localize essential histidines, the native, the DEP-modified, and the protected forms of isoform 1 were digested by trypsin. The resulting peptides were separated by HPLC. The peptides of interest were those with $R_t$ 11.34 and 40.93 min. The molecular masses of the two peptides were 5,732 and 2,540 daltons, respectively. When the data from the peptide analysis were checked with the sequence of CGTase, then His-140 and His-327 were identified as essential histidines in the active site of isoform 1.