• The Korean Journal of Zoology
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• v.29 no.2
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• pp.107-120
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• 1986

The activities of serum of serum lactate dehydrogenase (SLDH), serum alkaline phosphatase (SALP), serum creatine phosphokinase (SCPK), and their isozymes were determined in adult male Sprague-Dawley rats acclimated to cold environment $(4\\pm1^\\circC)$ for 36 days. The SLDH activity was significantly higher in the early stage of acclimated period. The steady state of SLDH activity seemed to be reached by the end of acclimated period. Electrophoretic separation of serum of control rat showed three SLDH isozymes. Isozymes SLDH4 and SLDH5 appeared most prominently, whereas only trace of SLDH1 or SLDH2 was found. The increase in SLDH level during acclimation to cold environment is a reflection of an immediate increase in the SLDH1, SLDH2, and SLDH3 type of SLDH isozyme. The acclimation to cold environment increased significantly level of SALP in the early state of acclimated period. SALP activity showed a attaining steady state with the resting level after transient rise. Electrophoretic separation of SALP of control rats showed the SALP1 and SALP2 fractions. The transient rise in SALP activity of rats acclimated to cold environment coincided with a transient rise in SALP1 fraction. Immediately after exposure to cold environment, there was significant elevation in SCPK activity. Value returned to normal after transient rise. A new steady state of SCPK activity seemed to be reached by 36 days. It may be inferred from the above data that thermal compensation appears to result from a change in the activity of an enzyme and that the SLDH, SLDH-isozyme, SALP-isozyme, and SCPK may be involved directly or indirectly in thermoregulation during acclimation to cold environment.

• Journal of Life Science
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• v.8 no.6
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• pp.638-647
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• 1998

Protein Kinase C (PKC) activators, phorbol 12-myristate 13-acetate (PMA), bryostatin, and dioctanoyl glycerol (DiC8), induce translocation of PKC isozymes from cytoplasm to plasma membrane or into nucleus. The activated PKC negatively modulates growth of human breast cancer cells. Antiproliferative effect and translocation of PKC were investigated in MCF-7 cells. The translocation of activated PKC isozymes by PMA, bryostatin and DiC8 was occurred at the various different regions in MCF-7 cell. PKC $\alpha$ and $\beta$ could be translocated to the nucleus or the nuclear mem-brane, and PKC $\delta$and $\varepsilon$ to cell membrane by PMA while DiC8 and bryostatin induced the translocation of PKC $\alpha$ and $\beta$ to the nucleus or plasma membrane, respectively. In the antiproliferative effect of PKC activators, PMA ($IC_{50}$/ values of 1.2$\pm$0.3nM) and DiC8 ($IC_{50}$/ values of 5.0$\pm$1.1$\mu$M) inhibited the cell growth. Bryostatin also inhibited the cell growth but to a much less degree than one obser-ved with PMA : 16% growth reduction by 100nM bryostatin. However, PMA treated with bryostatin induced gro-wth inhibition, but PMA with DiC8 at 10$\mu$M was not effective. These results suggest that each PKC isozyme is tran-slocated to various specific sites, and that especially, PKC $\alpha$ isozyme plays an important role in control of antiprolife-raive function of cell growth.

• Journal of fish pathology
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• v.20 no.2
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• pp.119-127
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• 2007

Phosphoinositide-specific phospholipase Cδ (PLCδ) plays an important role in many cellular responses and is involved in the production of second messenger. The present study was conducted to characterize the catalytic and regulatory properties of the PLCδ of Misgurnus mizolepis (ML-PLCδ). The ML-PLCδ gene was cloned and expressed under according to the method of the previous report (Kim et al., 2004), and its recombinant protein was purified by successive chromatography using Ni2+-NTA affinity column. The recombinant ML-PLCδ showed a concentration-dependent PLC activity to phosphatidylinositol 4,5-bisphosphate (PIP2) or phosphatidylinositol (PI). Its activity was absolutely Ca2+-dependence, which was similar to mammalian PLCδ isozymes. The Ca2+ concentration yielding maximal activation of ML-PLCδ was 100 μM. However, the activity was decreased interestingly by a polyamine, such as spermine and spermidine. In vitro assay using cholate-micelle cell, ML-PLCδ activity was inhibited in dose-dependent manner by sphinogosine but increased by phosphocholine . In the lipid-binding assay, ML-PLCδ was strongly bound to LPA, PI(3)P, PI(4)P, PI(5)P, PI(3,5)P2, PI(4,5)P2, PI(3,4,5)P3 and PA, but it showed the low affinity to S1P, PI(3,4)P2 and PS. Taken together our results, it is suggested that the general catalytic and regulatory properties of ML-PLCδ are similar with those of mammalian PLCδ1 isozymes, but the N-terminal extended piscine phospholipase Cδ1 (ML-PLCδ) might reflect some distinctions in regulatory properties and inositol-lipid binding specificity between piscine ML-PLCδ and mammalian PLCδ isozymes.

• 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 Life Science
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• v.15 no.1 s.68
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• pp.80-86
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• 2005

To achieve the purpose of this study, forty-eight male Sprague-Dawley rats were assigned to control and three endurance exercise group. 36 rats were forced to exercise according to exercise intensity for 8 weeks and 12 rats were untrained for control group. Cardiac cytosol was extracted from cardiac tissue and cardiac mitochondria was purified from the cytosol. Purified mitochondria were separated into four fraction: inner membrane, outer membrane inter membrane space and matrix. The changes of cytosolic and mitochondrial LDH isozymes activity were measure. Relative activity $(\%)$ of cytosol for low and control group showed the following order of prevalence $AB_3>A_2B_2>B_4>A_3B>A_4$ for moderate and high group : $AB_3>B_4>A_2B_2>A_3B>A_4$. Outer membrane for low group showed $AB_3>B_4>A_2B_2$, for moderate group:$ B_4>AB_3>A_2B_2$, for high and control group: $B_4>A_3B$. Inter membrane space for low, moderate and high group showed $B_4>AB_3>A_2B_2>A_3B>A_4$, for control group: $B_4>A_3B>AB_3>A_2B_2>A_4$. Inner membrane for all group showed $B_4>AB_3>A_2B_2>A_3B>A_4$. Matrix for control, low, moderate and high group showed $B_4>AB_3>A_2B_2>A_3B>A_4$. These results suggest that long term exercise intensity effect on cardiac tissue cytosolic and mitochondrial activity and $A_4,\;A_3B,\;A_2B_2,\;AB_3\;and\;B_4$ isozymes were found entirely in mitochondrial fraction.

• Journal of Life Science
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• v.14 no.4
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• pp.702-707
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• 2004

In native-polyacrylamide gel electrophoresis of Pangasius polyuranodon, the lactate dehydrogenase (EC 1.1.1.27, LDH) $A_4$, $A_3$B, $A_2$$B_2$,$AB_3$ and $B_4$ isozymes were expressed in various tissues. The LDH $A_4$ and liver-specific $C_4$ isozymes were expressed in the tissues of Hypostomus Plecostomus. The bands of LDH in skeletal muscle, heart and eye tissues were not detected while one band was detected in kidney and liver, and four bands were detected in brain. The detected one band in liver was identified as alcohol dehydrogenase and an anodal band of skeletal muscle was identified as nothing dehydrogenase. The LDH in skeletal muscle, heart and eye might function as pyruvate reductase. The degree of inhibitions of LDH in skeletal muscle and heart of P. polyuranodon by 10 mM pyruvate were measured 57.6% and 73.8%, respectively. However, those of LDH in tissues of H. plecostomus were measured 52.7-61.8% so tissue specificity did not appear. Therefore, H. ple-costomus might be more acclimated to hypoxic environment by anaerobic metabolism of LDH iso-zymes than P. polyuranodon.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.151-157
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• 1986

Population of the green peach aphid, Myzus persicae(Sulz.), were successively selected(up to 20th generation) in the laboratory by the insecticide oxydemeton-methyl (Metasystox-R 25Ec) and the resistance was linearly increased with the selected generations. The population developed 355.5-to 359.9-fold resistance to oxydemeton-methyl at 20th generation-selection. The population showed cross resistance to the insectides cypermethrin(770.1-to 778.5-fold), acephate(25.6-to 33.2-fold) and pirimicarb(3.4-to 3.6-fold). The different esterase isozymes were detected by the electrophoresis from the selected and non-selected strains and the band of the ${\beta}-2$ from the selected strain showed greater esterase activity than that of the non. selected strain.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.213-218
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• 2010

Lactate dehydrogenases (LDHs) have been highly focused for long time, due to their important roles in biochemical and metabolic pathways of cells. On the basis of genome-wide searching results, three putative LDH genes from Bacillus cereus ATCC 14579 genome have been PCR-amplified, cloned, and well-expressed in E. coli. All three BcLDH isozymes are supposed to share highly conserved catalytic amino acid residues in common $NAD^+$-dependent LDHs. Meanwhile, BcLDH1 consisting of 314 amino acids shares 86 and 49% of identities with BcLDH2 and 3, respectively. Interestingly, only BcLDH1 showed the converting activities between L-lactate and pyruvate in the presence of $NAD^+$ coenzyme, while the other isozymes are likely to have almost no activity. As a result, it was revealed that BcLDH1 can be a typical $NAD^+$-dependent L-lactate-specific dehydrogenase.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.21-21
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• 1995

The effects of plant hormones (NAA, $GA_3$ and BA) and light qualities (white, red, green and blue light) on the changes of reducing sugar contents and invertase isozyme activities in leaves of maize (Zea mars L.) and mung bean (Phseolw radiatus L.) seedlings were investigated. NAA accelerated the increase of reducing sugar contents and invertase isozyme activities, on the contrary, $GA_3$ had little effect in the accumulation of reducing sugar and in the increase of enzyme activities from the leaves of maize and mung bean seedlings. On the other hand, BA accelerated an increase in the activities of the invertase isozyme from the leaves of mung bean seedlings whereas it had little effect in the increase of the enzyme activities from those of maize seedlings. The accumulation of reducing sugar in leaves of both seedlings was promoted by red light irradiation compared to white light irradiation, while the activities of the enzyme were little affected by various light Qualities. In the simultaneous applications of plant hormone and light quality, NAA with white light was very effective in the increase of reducing sugar contents and the enzyme activities from the leaves of mung bean seedlings, whereas NAA application with blue light showed a prominent enhancement in the reducing sugar contents and the enzyme activities from those of maize seedlings. These results suggest that plant hormone, particularly NAA, may be a more important factor than various light Qualities in the stimulation of invertase activity.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.323-333
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• 1995

The effects of plant hormones (NAA, $GA_3$ and BA) and light qualities (white, red, green and blue light) on the changes of reducing sugar contents and invertase isozyme activities in leaves of maize (Zea mars L.) and mung bean (Phseolw radiatus L.) seedlings were investigated. NAA accelerated the increase of reducing sugar contents and invertase isozyme activities, on the contrary, $GA_3$ had little effect in the accumulation of reducing sugar and in the increase of enzyme activities from the leaves of maize and mung bean seedlings. On the other hand, BA accelerated an increase in the activities of the invertase isozyme from the leaves of mung bean seedlings whereas it had little effect in the increase of the enzyme activities from those of maize seedlings. The accumulation of reducing sugar in leaves of both seedlings was promoted by red light irradiation compared to white light irradiation, while the activities of the enzyme were little affected by various light Qualities. In the simultaneous applications of plant hormone and light quality, NAA with white light was very effective in the increase of reducing sugar contents and the enzyme activities from the leaves of mung bean seedlings, whereas NAA application with blue light showed a prominent enhancement in the reducing sugar contents and the enzyme activities from those of maize seedlings. These results suggest that plant hormone, particularly NAA, may be a more important factor than various light Qualities in the stimulation of invertase activity.