• BMB Reports
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• v.40 no.6
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• pp.1077-1082
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• 2007

Human glutamate dehydrogenase exists in hGDH1 (housekeeping isozyme) and in hGDH2 (nerve-specific isozyme), which differ markedly in their allosteric regulation. In the nervous system, GDH is enriched in astrocytes and is important for recycling glutamate, a major excitatory neurotransmitter during neurotransmission. Chloroquine has been known to be a potent inhibitor of house-keeping GDH1 in permeabilized liver and kidneycortex of rabbit. However, the effects of chloroquine on nerve-specific GDH2 have not been reported yet. In the present study, we have investigated the effects of chloroquine on hGDH2 at various conditions and showed that chloroquine could inhibit the activity of hGDH2 at dose-dependent manner. Studies of the chloroquine inhibition on enzyme activity revealed that hGDH2 was relatively less sensitive to chloroquine inhibition than house-keeping hGDH1. Incubation of hGDH2 was uncompetitive with respect of NADH and non-competitive with respect of 2-oxoglutarate. The inhibitory effect of chloroquine on hGDH2 was abolished, although in part, by the presence of ADP and L-leucine, whereas GTP did not change the sensitivity to chloroquine inhibition. Our results show a possibility that chloroquine may be used in regulating GDH activity and subsequently glutamate concentration in the central nervous system.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.898-904
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• 2014

The stability of Bacillus licheniformis alpha-amylase (BLA) under acid condition was enhanced through direct evolution using the error-prone polymerase chain reaction. One beneficial mutation site, H281I, was obtained in BLA. The specific activity of H281I was 161/352 U/mg, which was 62.6/27.5% higher than that of the wild-type (WT) (99/276 U/mg) at pH 4.5/6.5 and $95^{\circ}C$. The pH optimum for H281I was decreased about 1 unit, whereas no significant changes of optimum temperature and thermostability were observed compared with the wild type (WT). The $k_{cat}/K_m$ value of H281I was 1.7-/1.4-fold higher at pH 4.5/6.5, respectively, than that of WT. The structure model analysis indicated that the H281I mutation altered the predicted interaction between the amino acid residues at 281 and 273, thus creating a conducive local environment for substrate binding, as reflected by its decreased $K_m$, and consequently increased the specific activity.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.340-347
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• 1999

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with none marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocutured DCs was able to induce complete protectiv immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DC s induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be used for designing tumor vaccines using DCs when the information about tumor antigens is limited.

• The Journal of Korean Physical Therapy
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• v.31 no.1
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• pp.49-55
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• 2019

Purpose: This study examined the effects of taping therapy on the balance and gait of stroke patients. Methods: The subjects of this study were 30 stroke patients. The treatment groups were prescribed a combination of taping, therapy applied simultaneously to the ankle and the hip joint, and general physical therapy twice a day for 30 minutes each, five days per week for 4 weeks for a total of 40 times. The control group was treated with general physical therapy for 30 minutes, 5 times per week for 4 weeks, and total 40 times. All subjects were followed up on a Berg balance scale, timed up and go test, activity-specific balance confidence scale, and GaitRite. Results: The group that simultaneously received taping therapy to the ankle and hip joint showed more significant effects than the group treated with ankle joint taping only (p<0.05). Effects were noted in the Berg balance scale, timed up and go test, activity-specific balance confidence scale and gait ability test. Compared to the control group, the group treated at the ankle and hip joint showed significant effects after the experiment in the Berg balance scale, timed up and go test, activity-specific balance confidence scale, and gait ability test (p<0.05). Conclusion: Taping therapy applied to both the ankle and hip joints, and combined with general physical therapy appears to be effective in patients with chronic stroke who have an impaired balance and gait ability.

• BMB Reports
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• v.28 no.3
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• pp.227-231
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• 1995

In order to figure out the relationships between structural features and biological activity of the host-specific HC-toxin in maize, structurally related cyclic tetrapeptides, chlamydocin and CYL-2 were isolated, and their biological activities in maize were examined. Biological activities of preparations were determined by root growth inhibition and electrolyte leakage bioassays. Chlamydocin and CYL-2 showed toxicities to maize. However, the toxicities of these compounds were non-specific. Thus, the precise peptide ring structure of HC-toxin apparently does not play an important role in toxicity, while resistance of maize to HC-toxin is based on a precise ring conformation.

• Mycobiology
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• v.39 no.2
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• pp.125-128
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• 2011

Enzyme activities of Cenococcum geophilum isolates were examined on enzyme- specific solid media. Deoxyribonuclease, phosphatase, and urease were detected in all isolates, whereas cellulase was not detected in any of the isolates. Variations in enzyme activities of amylase, caseinolysis, gelatinase, lipase, and ribonuclease were observed among isolates.

• Korean Journal of Microbiology
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• v.29 no.4
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• pp.209-214
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• 1991

The PRD1 DNA polymerase is a small multi-functional enzyme containing conserved amino acid sequences shared by family B DNA polymerases. Thus the PRD1 DNA polymerase provides an useful model system with which to study structure-functional relationships of DNA polymerase molecules. In order to investigate the functional and structural roles of the highly conserved amino acid sequences, we have introduced three mutations into a conserved amino acid of the PRD1 DNA polymerase. Genetic complememtation study indicated that each mutation inactivated DNA polymerase catalytic activity.

• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.15-15
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• 1997

Recent studies indicate that hydrogen peroxide (H$_2$O$_2$), which is one of the reactive oxygen species involved in the oxidative stress, is an intracellular secondary messenger in the signal transduction. A novel family of thiol specific antioxidant (TSA) enzymes with a peroxidase activity shows no sequence homology to previously known antioxidant enzymes.(omitted)

• Journal of Korean Academy of Fundamentals of Nursing
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• v.20 no.3
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• pp.220-229
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• 2013

Purpose: The purpose of the study was to investigate activities-specific balance confidence and risk of fallings among rehabilitation patients with impaired of mobility, and to identify the influence of activities-specific balance confidence on their risk of fallings. Method: Data for 132 rehabilitation patients were collected between October June 20 and August 20, 2012 at nine hospitals in a metropolitan city. Data were analyzed using t-test, ANOVA, Pearson correlation coefficient and stepwise multiple regression with SPSS/WIN 20.0. Result: The mean score for rehabilitation patients' activities-specific balance confidence was 40.18 out of a possible range of 0-100 and the mean score for risk of fallings among rehabilitation patients was 31.10 within a possible range of 0-125. Significant factors affecting the risk of fallings among the rehabilitation patients were 'activity level', 'dementia', 'body mass index', 'anxiety', and 'presence of a caregiver', which together explained 34.7% of the variance. The most significantly factor influencing rehabilitation patients' risk of fallings was activities-specific balance confidence which explained 23.5% of the variance. Conclusion: The study results indicate that activities-specific balance confidence as well as physical factors should be considered for interventions to decrease risk of fallings in rehabilitation patients with impaired mobility.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.82-82
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• 1995

Regulation of enzyme synthesis by transcriptional and translational control systems provides rather stable adaptation to change of amino acid level in the growth medium, while manipulation of enzyme activity through endproduct feedback inhibition represents rather short-term and reversible ways of adjusting metabolic fluctuation of amino acid level. Various control mechanisms interplay to regulate genes encoding enzymes for amino acid biosynthesis in the yeast, Sacchromyces cerevisiae. When amino acids are in short supply, genes under a cross-pathway regulatory mechanism Or general amino acid control (general control) increase their action, in which Gcn4p is the major positive regulator of gene expression. When cells are cultured in minimal medium, basal level expression is also regulated by supplementary control elements, where inorganic phosphate level is additionally involved. Most of amino acid biosynthetic genes are also regulated by the level of endproduct of the pathway. This pathway-specific regulatory mechanism is called specific amino acid control (specific controD, under which gene expression is reduced when endproduct is present in the medium. Derepression of a gene through general control can be usually overridden by repression through specific control, where the endproduct level of that particular pathway is high and not limiting. In this presentation, regulatory factors for basal level expression and general control of yeast amino acid biosynthesis will be discussed, m addition to pathway-specific repression patterns and interaction between CrOSS- and specific-control mechanisms. Preliminary results are also presented from the investigation of the cloned genes in the threonine biosynthetic pathway of the yeast. yeast.