• Journal of Microbiology and Biotechnology
• /
• v.9 no.1
• /
• pp.119-121
• /
• 1999

Tumor cell interaction with the extracellular matrix is defined as the critical event of tumor invasion that signals the initiation of a metastatic cascade. Sesquicillin has been identified as an inhibitor of melanoma cell adhesion to the components of the extracellular matrix (ECM) in cultured broth of fungal strain F60063. Sesquicillin strongly inhibited the adhesion of B16 melanoma cells to laminin, fibronectin, and typeIV collagen. It also inhibited B16 melanoma cell invasion of reconstituted basement membrane Matrigel in vitro in a dose-dependent manner. These results suggest that sesquicillin is a new class of nonpeptidic ECM adhesion inhibitor having anti-invasive activity.

• Korean Journal of Microbiology
• /
• v.38 no.4
• /
• pp.254-259
• /
• 2002

A psychrotrophic bacterium was isolated from Antarctic marine sediment and identified as Shewanella sp. species based on the biochemical properties and 16S rRNA sequence, and designated as Shewanella sp. L93. Extracellular protease produced by this strain was purified through ammonium sulfate precipitation, High-Q column chromatography, first gel permeation chromatography, BioScale Q2 ion exchange chromatography and second gel permeation chromatography, and basic properties of this enzyme were investigated.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.1
• /
• pp.178-181
• /
• 2004

A gene encoding an extracellular nuclease was cloned from Aeromonas hydrophila strain ATCC14715. The gene was overexpressed and the enzyme was purified by fusing to maltose binding protein. It was shown that the protein possessed DNase activity on both single-stranded and double-stranded DNAs. It exhibited both endo- and exonuclease activities. It was also shown that the protein had an RNase activity. Possible roles of this extracellular enzyme in the A. hydrophila life cycle are discussed.

• Archives of Pharmacal Research
• /
• v.18 no.4
• /
• pp.249-255
• /
• 1995

The changes in the levels of the extracellular dopamine metabolites and the responses to various dopamine agents were studied by using microdialysis inhyperglycemic rat striatum. The hyperglycemia were induced by the administriation of streptozotocin (40 mg/kg, i.p. for 3 days.). The basal levels of striatal dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were significantly decreased in hyperglycemic rat striatum. After the administration ofl D-1 and D-2 receptor antagonists, SCH-23390 and (-)sulpiride, to rats 14 days after the last administration of STZ, the increased rates in DOPAC levels were higher in hyper- than in normoglycemic rats. However, after the administration of dopamine autoeceptor agonist, 3(-)PPP, the levels of the extracellular HVA were increased in normoglycemic rats, but those were not altered in hyperglycemic rats. The results indicate that the striatal dopamine activities were decreased in the hyperglycemic rats and suggest that release of dopamine may be decreased in hyperglycemic rats. Furthermore it suggest that the increase in the levels of the extracellular dopamine metabolites by dopamine antagonists might be dur to the incrrased sensitivities of the dopamine receptors in hyperglycemic state.

• Journal of Microbiology and Biotechnology
• /
• v.6 no.6
• /
• pp.381-385
• /
• 1996

Three distinct plasmids, with approximate molecular weights of 1, 4.5, and 33 megadaltons, were found in Lactococcus lactis subsp. lactis (L. lactis) ML8. Slow acid-producing mutants of L. lactis ML8, isolated by plasmid curing with acriflavine treatment, lacked the 33-megadalton plasmids. The plasmid-cured mutant showed lactose-negative (Lac) characteristics and the alteration of extracellular proteinase pattern. The possible involvement of extracellular proteinase with the 33-megadalton plasmid is highlighted in this research.

• Journal of Microbiology
• /
• v.42 no.2
• /
• pp.156-159
• /
• 2004

In general, the salinity of the ocean is close to 3.5％ and marine vibrios possess the respiratory chain-linked Na$\^$+/ pump. The influence of sodium chloride and the proton conductor carbonylcyanide m-chlo-rophenylhydrazone (CCCP) on the production of extracellular proteases in a marine Vibrio strain was examined. At the concentration of 0.5 M, sodium chloride minimally inhibited the activity of extra-cellular proteases by approximately 16％, whereas at the same concentration, the producton of extra-cellular proteases was severely inhibited. On the other hand, the production of extracellular proteases was completely inhibited by the addition of 2 ${\mu}$M CCCP at pH 8.5, where the respiratory chain-linked Na$\^$+/ pump functions.

• KSBB Journal
• /
• v.16 no.2
• /
• pp.158-162
• /
• 2001

A halotolerant and extracellular protease-producing yeast was isolated from traditional Meju and identified as a strain of Hansenular polymorpha by investigating its microbiological characteristics. The optimum pH, temperature and NaCl concentration reauired for the growth of Hansenular polymorpha S-9 were found to be pH 6.0, 30$^{\circ}C$ and 0.5 M, respectively. Extracellular protease was produced maximally at 10 U ml(sup)-1 when Hansenular polymorpha S-9 was grown on the medium containing 1.0% beef extract and 0.1 M NaCl for 12 hr at 30$^{\circ}C$. About 13% of the angiotensin-converting enzyme (ACE) inhibitory activity was shown in the hydrolysates which were obtained from the digestion of soybean protein (6 mg) for 6 hr at 30$^{\circ}C$ by the crude enzyme (1 U).

• Applied Microscopy
• /
• v.48 no.4
• /
• pp.96-101
• /
• 2018

The release of nanoscale membrane-bound vesicles is common in all three domains of life. These vesicles are involved in a variety of biological processes such as cell-to-cell communication, horizontal gene transfer, and substrate transport. Prokaryotes including bacteria and archaea release membrane vesicles (MVs) (20 to 400 nm in diameter) into their extracellular milieu. In spite of structural differences in cell envelope, both Gram-positive and negative bacteria produce MVs that contain the cell membrane of each bacterial species. Archaeal MVs characteristically show surface-layer encircling the vesicles. Filamentous fungi and yeasts as eukaryotic microbes produce bilayered exosomes that have varying electron density. Microbes also form intracellular vesicles and minicells that are similar to MVs and exosomes in shape. Electron and fluorescence microscopy could reveal the presence of DNA in MVs and exosomes. Given the biogenesis of extracellular vesicles from the donor cell, in situ high-resolution microscopy can provide insights on the structural mechanisms underlying the formation and release of microbial extracellular vesicles.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2001.02a
• /
• pp.37-37
• /
• 2001

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.10
• /
• pp.1398-1406
• /
• 2016

In general, the seminiferous tubule basement membrane (STBM), comprising laminin, collagen IV, perlecan, and entactin, plays an important role in self-renewal and spermatogenesis of spermatogonial stem cells (SSCs) in the testis. However, among the diverse extracellular matrix (ECM) proteins constituting the STBM, the mechanism by which each regulates SSC fate has yet to be revealed. Accordingly, we investigated the effects of various ECM proteins on the maintenance of the undifferentiated state of SSCs in pigs. First, an extracellular signaling-free culture system was optimized, and alkaline phosphatase (AP) activity and transcriptional regulation of SSC-specific genes were analyzed in porcine SSCs (pSSCs) cultured for 1, 3, and 5 days on non-, laminin- and collagen IV-coated Petri dishes in the optimized culture system. The microenvironment consisting of glial cell-derived neurotrophic factor (GDNF)-supplemented mouse embryonic stem cell culture medium (mESCCM) (GDNF-mESCCM) demonstrated the highest efficiency in the maintenance of AP activity. Moreover, under the established extracellular signaling-free microenvironment, effective maintenance of AP activity and SSC-specific gene expression was detected in pSSCs experiencing laminin-derived signaling. From these results, we believe that laminin can serve as an extracellular niche factor required for the in vitro maintenance of undifferentiated pSSCs in the establishment of the pSSC culture system.