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642 results on '"Na, Byoung-Kuk"'

8. Global research alliance in infectious disease: a collaborative effort to combat infectious diseases through dissemination of portable sequencing

Author

Runtuwene, Lucky R., Sathirapongsasuti, Nuankanya, Srisawat, Raweewan, Komalamisra, Narumon, Tuda, Josef S. B., Mongan, Arthur E., Aboge, Gabriel O., Shabardina, Victoria, Makalowski, Wojciech, Nesti, Dela Ria, Artama, Wayan T., Nguyen-Thi, Lan Anh, Wan, Kiew-Lian, Na, Byoung-Kuk, Hall, William, Pain, Arnab, Eshita, Yuki, Maeda, Ryuichiro, Yamagishi, Junya, and Suzuki, Yutaka

Published
2022
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11. The anti-amoebic activity of Pinus densiflora leaf extract against the brain-eating amoeba Naegleria fowleri.

Author

Lê, Hương Giang, Kim, Woong, Kang, Jung-Mi, Võ, Tuấn Cường, Yoo, Won Gi, Cheong, Hyeonsook, and Na, Byoung-Kuk

Subjects
JAPANESE red pine, PLANT extracts, NAEGLERIA fowleri, GENE ontology, DRUG efficacy
Abstract

Naegleria fowleri invades the brain and causes a fatal primary amoebic meningoencephalitis (PAM). Despite its high mortality rate of approximately 97%, an effective therapeutic drug for PAM has not been developed. Approaches with miltefosine, amphotericin B, and other antimicrobials have been clinically attempted to treat PAM, but their therapeutic efficacy remains unclear. The development of an effective and safe therapeutic drug for PAM is urgently needed. In this study, we investigated the anti-amoebic activity of Pinus densiflora leaf extract (PLE) against N. fowleri. PLE induced significant morphological changes in N. fowleri trophozoites, resulting in the death of the amoeba. The IC50 of PLE on N. fowleri was 62.3±0.95 µg/ml. Alternatively, PLE did not significantly affect the viability of the rat glial cell line C6. Transcriptome analysis revealed differentially expressed genes (DEGs) between PLE-treated and non-treated amoebae. A total of 5,846 DEGs were identified, of which 2,189 were upregulated, and 3,657 were downregulated in the PLE-treated amoebae. The DEGs were categorized into biological process (1,742 genes), cellular component (1,237 genes), and molecular function (846 genes) based on the gene ontology analysis, indicating that PLE may have dramatically altered the biological and cellular functions of the amoeba and contributed to their death. These results suggest that PLE has anti-N. fowleri activity and may be considered as a potential candidate for the development of therapeutic drugs for PAM. It may also be used as a supplement compound to enhance the therapeutic efficacy of drugs currently used to treat PAM. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Biochemical properties of a novel cysteine protease of Plasmodium vivax, vivapain-4.

Author

Na, Byoung-Kuk, Bae, Young-An, Zo, Young-Gun, Choe, Youngchool, Kim, Seon-Hee, Desai, Prashant V, Avery, Mitchell A, Craik, Charles S, Kim, Tong-Soo, Rosenthal, Philip J, and Kong, Yoon

Subjects
Cytoplasm, Vacuoles, Plasmodium vivax, Actins, Hemoglobins, Recombinant Proteins, Amino Acid Substitution, Mutagenesis, Site-Directed, Substrate Specificity, Hydrogen-Ion Concentration, Mutant Proteins, Aspartic Acid Endopeptidases, Cysteine Proteases, Tropical Medicine, Biological Sciences, Medical and Health Sciences
Abstract

BackgroundMultiple cysteine proteases of malaria parasites are required for maintenance of parasite metabolic homeostasis and egress from the host erythrocyte. In Plasmodium falciparum these proteases appear to mediate the processing of hemoglobin and aspartic proteases (plasmepsins) in the acidic food vacuole and the hydrolysis of erythrocyte structural proteins at neutral pH. Two cysteine proteases, vivapain (VX)-2 and VX-3 have been characterized in P. vivax, but comprehensive studies of P. vivax cysteine proteases remain elusive.FindingsWe characterized a novel cysteine protease of P. vivax, VX-4, of which orthologs appears to have evolved differentially in primate plasmodia with strong cladistic affinity toward those of rodent Plasmodium. Recombinant VX-4 demonstrated dual substrate specificity depending on the surrounding micro-environmental pH. Its hydrolyzing activity against benzyloxycarbonyl-Leu-Arg-4-methyl-coumaryl-7-amide (Z-Leu-Arg-MCA) and Z-Phe-Arg-MCA was highest at acidic pH (5.5), whereas that against Z-Arg-Arg-MCA was maximal at neutral pH (6.5-7.5). VX-4 preferred positively charged amino acids and Gln at the P1 position, with less strict specificity at P3 and P4. P2 preferences depended on pH (Leu at pH 5.5 and Arg at pH 7.5). Three amino acids that delineate the S2 pocket were substituted in VX-4 compared to VX-2 and VX-3 (Ala90, Gly157 and Glu180). Replacement of Glu180 abolished activity against Z-Arg-Arg-MCA at neutral pH, indicating the importance of this amino acid in the pH-dependent substrate preference. VX-4 was localized in the food vacuoles and cytoplasm of the erythrocytic stage of P. vivax. VX-4 showed maximal activity against actin at neutral pH, and that against P. vivax plasmepsin 4 and hemoglobin was detected at neutral/acidic and acidic pH, respectively.ConclusionVX-4 demonstrates pH-dependent substrate switching, which might offer an efficient mechanism for the specific cleavage of different substrates in different intracellular environments. VX-4 might function as a hemoglobinase in the acidic parasite food vacuole, a maturase of P. vivax plasmepsin 4 at neutral or acidic pH, and a cytoskeleton-degrading protease in the neutral erythrocyte cytosol.

Published
2010

29. Phragmites australis (Cav.) Trin. ex Steud. Extract Induces Apoptosis-like Programmed Cell Death in Acanthamoeba castellanii Trophozoites

Author

Lê, Hương-Giang, primary, Choi, Ji-Su, additional, Hwang, Buyng-Su, additional, Jeong, Yong-Tae, additional, Kang, Jung-Mi, additional, Võ, Tuấn-Cường, additional, Cho, Pyo-Yun, additional, Lee, Young-Kyung, additional, Yoo, Won-Gi, additional, Hong, Yeonchul, additional, Oh, Young-Taek, additional, and Na, Byoung-Kuk, additional

Published
2022
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33. Molecular Profiles of Multiple Antimalarial Drug Resistance Markers in Plasmodium falciparum and Plasmodium vivax in the Mandalay Region, Myanmar

Author

Lê, Hương Giang, primary, Naw, Haung, additional, Kang, Jung-Mi, additional, Võ, Tuấn Cường, additional, Myint, Moe Kyaw, additional, Htun, Zaw Than, additional, Lee, Jinyoung, additional, Yoo, Won Gi, additional, Kim, Tong-Soo, additional, Shin, Ho-Joon, additional, and Na, Byoung-Kuk, additional

Published
2022
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47. Additional file 2 of Population genetic analyses inferred a limited genetic diversity across the pvama-1 DI domain among Plasmodium vivax isolates from Khyber Pakhtunkhwa regions of Pakistan

Author

Ullah, Ibrar, Afridi, Sahib Gul, Israr, Muhammad, Khan, Hizbullah, Shams, Sulaiman, Zaib, Komal, Le, Huong Giang, Kang, Jung-Mi, Na, Byoung-Kuk, and Khan, Asifullah

Abstract

Additional file 2: Table S1. The haplotypes identified in pvama-1 DI region of KP, Pakistan P. vivax isolates.

Published
2022
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49. Additional file 4 of Population genetic analyses inferred a limited genetic diversity across the pvama-1 DI domain among Plasmodium vivax isolates from Khyber Pakhtunkhwa regions of Pakistan

Author

Ullah, Ibrar, Afridi, Sahib Gul, Israr, Muhammad, Khan, Hizbullah, Shams, Sulaiman, Zaib, Komal, Le, Huong Giang, Kang, Jung-Mi, Na, Byoung-Kuk, and Khan, Asifullah

Abstract

Additional file 4: Fig S3. Pearson correlation plot of KP and global pvama-1 samples based on pairwise Fst values. The plot shows clustering and correlation between the groups in hierarchical order. The dark brackets and large sizes depict the minimum genetic distinction and high correlation.

Published
2022
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50. Additional file 3 of Population genetic analyses inferred a limited genetic diversity across the pvama-1 DI domain among Plasmodium vivax isolates from Khyber Pakhtunkhwa regions of Pakistan

Author

Ullah, Ibrar, Afridi, Sahib Gul, Israr, Muhammad, Khan, Hizbullah, Shams, Sulaiman, Zaib, Komal, Le, Huong Giang, Kang, Jung-Mi, Na, Byoung-Kuk, and Khan, Asifullah

Abstract

Additional file 3: Fig S2. Linkage disequilibrium (LD) pattern of pvama-1 DI sequences of P. vivax isolates from KP, Pakistan. The LD index (R2) (Y-axis) plotted against nucleotide distance (X-axis) using a two tailed Fisher’s exact test.

Published
2022
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