• The Korean Journal of Mycology
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• v.27 no.5 s.92
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• pp.328-336
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• 1999

Isozyme comparisons of mycelial extracts from Pleurotus ostreatus were undertaken using isoelectric focusing. Enzyme isozyme patterns were Used to describe the extent of geographical diversity and degree of intraspecific variation in these extracts. A total of 77 bands were resolved from six different enzymes. Cluster analyses were performed using the zymograms for esterase (EST), glucose phosphate isomerase (GPI), leucine aminopeptidase (LAP), malate dehydrogenase(MDH), peroxidase (POX), and phosphoglucomutase (pGM). EST gave multiple banding patterns, while less variability was observed for GPI, MDH, and PGM. Cluster analyses demonstrated that strains of P. ostreatus from geographically different origins are genetically divergent, supporting the idea that there is little or no gene flow between these geographically distant population groups.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.90-94
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• 2001

Wondonins A and B, aromatic alkaloids of an unprecedented skeletal class have been isolated form and association of the sponges Poecillastra wondoensis and Jaspis sp. In addition, four novel bromotyrosine-derived metabolites, psammaplins $A_1$ and $A_2$, aplysinellins A and B, have been isolated from the tropical sponge Aplysinella rhax. The structures of these compounds have been determined on the basis of combined chemical and spectral analyses. The new compounds exhibited significant cytotoxicity and antiangiogenic activity as well as inhibitory activities against farnesyl protein transferase and leucine aminopeptidase. In addition to these compounds, several bioactive metabolites have been isolated from sponges of Korean and tropical waters.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.200-204
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• 2006

The enzymology of an activated sludge system for a petroleum wastewater purification process was investigated. Leucine-aminopeptidase (L-AMP), ${\beta}$-glucosidase (${\beta}-GLC$), and lipase (LIP) were selected for the study. It was found that more than 81.7% of enzymatic activity was associated with microbial cells in the activated sludge floc. The metabolic response of a mixed microbial population to increased phenol concentration showed that L-AMP activity increased in the activated sludge, whereas activities of ${\beta}-GLC$ and LIP decreased, due to the inhibitory effect of the phenol which varied from 100 mg/l to 500 mg/l.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.110-110
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• 2005

• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.68-75
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• 1981

The genetic structures at one leucine aminopeptidase locus (LAP-A) of acorns, seedling raised in greenhouse and forest form the two beech provenances. West Germany and Rumania, were investigated and compared with each other. In many pair wise comparisons significant differences in genotypic structure as well as genic structure were ascertained between different developmental stages. In both the provenances, the allele $A_2$ seems to have advantage at both seedling stages raised under two different conditions. Homozygous carriers of $A_2$ allele survived best in greenhouse, while heterozygous carriers especially with $A_2$ allele possessed great viability under more variable environmental conditions. Since a distinct different genetic background was present in two base populations, the identical effect of the allele $A_2$ confirms the adaptiveness of this locus. With aid of some measures such as viability parameter and genetic distance, the character of occurred viability selection of further explained. The possible significance of this locus at this early stage is discussed in relation to adaptation of this long lived tree species to heterogeneous environment.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.109-117
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• 1984

Allozyme study for open pollinated seeds of forty nine pitch pine families in an $F_1$-hybrid seed orchard demonstrated that allozyme variants in aspartate aminotransferase(AAT), glutamate dehydrogenase(GDH) and leucine aminopeptidase(LAP) systems are encoded by at Least eight loci; five for AAT, one for GDH and two fur LAP. Allozyme variations showed polymorphisms at seven of the eight loci, except GDH. Average number of alleles examined over six loci were 2.33 and 2.67 for maternal and progeny groups, respectively. Average heterozygosity and genetic diversity computed over six loci were, respectively, 0.235 and 5.409 for maternal tree group, 0.238 and 5.569 for progeny group. The proportion of $F_1$-hybrid seeds estimated by allozyme analysis was 0.77%. The estimated proportion of $F_1$ hybrid seeds by allozyme study is in good agreement with the value 0.73% estimated by morphological study for the proportion of pitch ${\times}$ Loblolly $F_1$ hybrid seedlings at a nursery. Indications for Wahlund effect, high levels of self-fertilization and for non-random matings in the $F_1$ hybrid seed orchard call for cautions in estimating allele frequency changes and mating probabilities for the parental and progeny groups.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.111-115
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• 2015

Two new analogs of bestatin were prepared from $\small{D}$-leucine and $\small{D}$-valine in a stereoselective and efficient way. An aminopeptidase inhibitor bestatin shows significant biological effects on immunomodulation and is marketed for the treatment of acute myelocytic leukemia. The key intermediates, trans-oxazolidine methyl esters 2a and 2b, were obtained with more than 20 to 1 stereoselectivity in a one-pot procedure by the three cascade reactions between N-hydroxymethyl protected ${\alpha}$-amino aldehydes (4a and 4b) and phenylsulfonylnitromethane ($PhSO_2CH_2NO_2$) and the following in-situ ozonolysis. Basic hydrolysis of 2a and 2b, and then the peptide coupling with $\small{L}$-Leu-OMe produced the protected derivatives of two new bestatin analogs, 3a and 3b, respectively. The new isobutyl and isopropyl analogs of bestatin (1a and 1b) were produced in overall 51% and 38% yields, respectively, with high stereoselectivity from the corresponding protected ${\alpha}$-amino aldehydes 4 in a six-step process.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.275-288
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• 1999

To understand the effects of ocean-dumping of organic wastes on bacteria, bacterial abundance and production, and hydrolytic activities of aminopeptidase (AMPase) and ${\beta}$-glucosidase (${\beta}$-GLCase) were measured 5 times in the euphotic zone of the dumping and non-dumping areas of the East Sea from April 1996 to September 1997. Comparing the depth-integrated values of phytoplankton biomass and bacterial parameters over the euphotic zone of dumping area with those of non-dumping area, we found that activities of ${\beta}$-GLCase in the oceanic dumping area were always higher than those in the oceanic non-dumping area. Also, thymidine-based bacterial production always correlated significantly with leucine-based bacterial production in dumping area (balanced growth), but not in non-dumping area (unbalanced growth). These results seem to be bacterial responses to continuous dumping of organic matter into the dumping area. Further, a relationship between bacterial abundance and production was significant in dumping area, but insignificant in non-dumping area, indicating that control mechanisms of bacterial abundance were different in two areas. Relationships between other bacterial parameters varied with areas and seasons, suggesting that bacteria might be regulated by different factors in spring and summer. Further studies are required to test whether these seasonal variabilities of regulating factor are associated with changes in temperature, temperature-related phenomena, or characteristics of wastes.

• The Korean Journal of Mycology
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• v.26 no.2 s.85
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• pp.163-172
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• 1998

Thirty six strains of Pleurotus spp., from world-wide nations, were examined for interspecific isozyme variation. A comparison of isozymes in mycelial extracts of the fungal genus Pleurotus was made by polyacrylamide gel isoelectric focusing. A total of one hundred and sixty six bands was resolved from six isozymes. A cluster analysis was done based on the zymograms for esterase, glucosephosphate isomerase, leucine aminopeptidase, malate dehydrogenase, peroxidase, and phosphoglucomutase. From the isozyme analysis, esterase showed higher degree of variability, while it was observed less variability for the enzymes such as glucosephosphate isomerase, malate dehydrogenase, and phosphoglucomutase. The species P. ostreatus, whose taxon is controversial, was discriminated from P. pulmonarius, while P. florida was classified as a distinct taxon. The clustering of P. sapidus and P. spodoleucus strains appeared to be more difficult. It was found that some strains were included to another cluster based on electrophoretic banding patterns. These results show that this lack of congruence among data sets may help explain the taxonomic difficulty within the genus Pleurotus. A dendrogram of genetic similarities was presented, and applications of isozyme data to the systematics of these commercially important fungi was discussed.

• Journal of fish pathology
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• v.27 no.1
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• pp.25-33
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• 2014

Hydrolase activities of excretory-secretory products (ESP) and somatic extracts (SE) from Anisakis simplex sensu stricto (s.s.) and Anisakis pegreffii larvae were investigated by using API ZYM kit. In esterase group, acid phosphatase showed high activity from both of A. simplex (s.s.) and A. pegreffii. Esterase (C4) showed activity only from SE and A. simplex (s.s.) showed higher activity than A. pegreffii. Alkaline phosphatase, acid phosphatase and naphthol-AS-BI-phosphohydrolase showed higher activity in 3rd stage larvae than in 4th stage larvae of both species. In aminopeptidase group, only leucine arylamidase showed remarkable activity in SE of both anisakid species, and A. simplex (s.s.) SE showed higher activity than A. pegreffii SE. In glycosidase group, N-acetyl-${\beta}$-glucosaminidase, ${\alpha}$-mannosidase, ${\alpha}$-fucosidase showed higher activity in A. simplex (s.s.) than A. pegreffii, and 4th larvae showed higher activity than 3rd larvae. These differences in hydrolase activity of anisakid nematodes larvae are thought to be due to different metabolism such as growth, moulting, digestion and feeding.