• Korean Journal of Microbiology
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• v.39 no.3
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• pp.148-154
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• 2003

Moraxella sp. CK-l is known to inhibits the growth of Anabaena cylindrica, a cyanobacterium. It has been documented that the ability of this growth inhibition of Anabaena cylindrica was attributed to extracellular autolysin from Moraxella sp. CK-l. However, it remains to be elucidated identification and characterization of autolysin have yet been elucidated. In this study, we tried to purify and identify autolysin secreted from Moraxella sp. CK-l. Cells were grown in a complex liquid medium (BGC-11) and culture supernatants were collected, followed by ammonium sulfate fractionation. Fractions were further separated with anion exchange column, Mono-Q, in FPLC system and analyzed by SDS/PAGE. The fraction containing high autolysin activity showed a single distinct protein peak in anion column and molecular mass of about 17 kDa in SDS/PAGE. Nterminal amino acid sequencing of the protein was analyzed, of which result showed the homology with some proteases, including extracellular serine protease, Dichelobacter nodosus.

• Molecules and Cells
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• v.44 no.7
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• pp.517-528
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• 2021

A recent genetic study with Brucella abortus revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV secretion system (T4SS) and peptidoglycan hydrolase inhibitor A (PhiA) as an inhibitor of SagA. In this study, we determined the crystal structures of both SagA and PhiA. Notably, the SagA structure contained a PGN fragment in a space between the N- and C-terminal domains, showing the substrate-dependent hinge motion of the domains. The purified SagA fully hydrolyzed the meso-diaminopimelic acid (DAP)-type PGN, showing a higher activity than hen egg-white lysozyme. The PhiA protein exhibiting tetrameric assembly failed to inhibit SagA activity in our experiments. Our findings provide implications for the molecular basis of the SagA-PhiA system of B. abortus. The development of inhibitors of SagA would further contribute to controlling brucellosis by attenuating the function of T4SS, the major virulence factor of Brucella.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.145-146
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• 2000

The presence of cross-reacting muramidase in Lactobacillus delbrueckii ssp. bulgaricus ULl2 was shown by using monoclonal antibodies raised against an muramidase-2 of Enterococcus hirae ATCC 9790. The separation of protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by Western immunoblot confirmed the presence of one cross-reacting band in Enterococcus hirae with an estimated molecular mass of 80 kDa, L. bulgaricus cultured cells harvested after 4 and 12 h were submitted to different autolysin releasing procedures and the liberated products were allowed to cross-react with muramidase-2 antibodies in order to estimate the efficiency of each treatment. Although the cultured cells harvested after 4 h yielded only a slight immune-reaction in Western immunoblots against these enzyme monoclonal antibodies, a strong signal was observed for the cell walls obtained from the same experimental conditions and treated with Triton X-100 surfactant. The same phenomenon was also observed by light fluorescence microscopy. Immune-labelling followed by optical and electron microscopy have shown that the muramidase-2 of L. bulgaricus ULl2 was essentially localized in the innermost part of the cell wall.(omitted)

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.174.1-174
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• 1998

No Abstract, See Full Text

• Journal of Ginseng Research
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• v.7 no.1
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• pp.63-67
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• 1983

Bacillus subtilis grown on medium containing 0.1% trios fraction, 0.005% sodium deoxycholate, and 0.05% taurocholate respectively was shown to grow as filamentous form and contain 2.3 x 10-5M, 1 x 10-5M, and 2.3${\times}$10-5M of intracellular C-AMP, respectively. The concentration was 3 or 4 times lower than that of the control. But concentrations of extracellula: C-AMP were similar to that of the control. Such decrease in C-AMP concentration was shown to parallel with decrease in autolysin activity indicating 40% and 20% lower activity of Bacillus subtilis grown on medium containing 0.05% and 0. l% triol fraction respectively than that of the control, The activity was also shown to be in inverse proportion with the formation of filament .

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.69-73
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• 1989

Cellular autolytic enzyme was isolated from the supernatant fluid of exponentially growing cuiture of Cl. butyricum ID-113. The autolysin was partially pruified by ammonium sulfate fractionation, chromatography on DEAE-Sephadex A-50 and gel filtration through Sephadex G-200. This autolytic enzyme lysed SDS-treated cell wall fractions of Cl. butyricum ID, but not whole cells at all. Its optimum pH and temperature were 5.0 and 37$^{\circ}C$, respectively. This enzyme was relatively stable at neutral pH, but sensitive to heat treatment. Enzyme activity was not influenced by the addition of various divalent cation, but inhibited by Cu$^{++}$.

• Biomedical Science Letters
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• v.17 no.4
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• pp.355-361
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• 2011

We evaluated the performance of the NOW $Streptococcus$ $pneumoniae$ urinary antigen test, standard culture and polymerase chain reaction for detecting $S.$ $pneumoniae$. The urinary antigen test of pneumonia patients represented sensitivity at 72% and specificity at 79%. The results of PCR were targeting for autolysin ($lyt$A), pneumolysin ($ply$), and spn9828. The $lyt$A sensitivity and specificity stood at 56% and 87% respectively while $ply$ sensitivity reported 83% and specificity was 47%, sensitivity and specificity of spn9828 stood at 83% and 73% respectively. The results of urinary antigen test and three genes were all statistically meaningful within $P$ <0.05. When the urinary antigen test of $S.$ $pneumoniae$ was positive, the three kinds of genes were also likely to be positive. According to the result of urinary antigen test, the results of PCR presented a meaningful difference ($P$ <0.05). Especially, the urinary antigen test of $S.$ $pneumoniae$ was likely to be positive ($P$ <0.05) when more than two genes were positive in PCR results.

• Molecules and Cells
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• v.40 no.12
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• pp.935-944
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• 2017

More than 50% of sepsis cases are associated with pneumonia. Sepsis is caused by infiltration of bacteria into the blood via inflammation, which is triggered by the release of cell wall components following lysis. However, the regulatory mechanism of lysis during infection is not well defined. Mice were infected with Streptococcus pneumoniae D39 wild-type (WT) and lipase mutant (${\Delta}lipA$) intranasally (pneumonia model) or intraperitoneally (sepsis model), and survival rate and pneumococcal colonization were determined. LipA and autolysin (LytA) levels were determined by qPCR and western blotting. S. pneumoniae Spd_1447 in the D39 (type 2) strain was identified as a lipase (LipA). In the sepsis model, but not in the pneumonia model, mice infected with the ${\Delta}lipA$ displayed higher mortality rates than did the D39 WT-infected mice. Treatment of pneumococci with serum induced LipA expression at both the mRNA and protein levels. In the presence of serum, the ${\Delta}lipA$ displayed faster lysis rates and higher LytA expression than the WT, both in vitro and in vivo. These results indicate that a pneumococcal lipase (LipA) represses autolysis via inhibition of LytA in a sepsis model.

• Journal of Life Science
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• v.21 no.12
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• pp.1716-1720
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• 2011

A bacterium hydrolysing various organic materials including cellulose, protein, starch and lipid was isolated. The isolate was identified as Bacillus subtilis, and named Bacillus subtilis CK-2 in this paper. This bacterium showed optimal growth at $40\sim45^{\circ}C$, pH 6~9, and 0~3% of NaCl. B. subtilis CK-2 seemed to synthesis highly active autolysin. The hydrolytic enzymes produced by B. subtilis CK-2 were primary enzymes because extracellular enzyme activities varied similarly to the growth curve. The hydrolytic enzymes seemed to be stable at basic pH conditions. From these results, B. subtilis CK-2 was found to bea useful bacterial agent for composting, or for use in feed-production waste in agriculture, fishery, forest materials, livestock farming, and food.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.15-21
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• 1997

We studied the characteristics of extracellular autolysins from Moraxella sp. CK-1 which has been known to lyse the cyanobacterial cell walls. This bacterium excreted autolysins from the early exponential growth phase. These enzymes showed optimal action condition of 60-$70^{\circ}C$ and pH 9.0. Whereas $Na^{+}$, $K^{+}$ and $Li^{+}$ ions exhibited positive effect on the enzyme activity, $Ba^{2+}$, $Mg^{2+}$, $Ca^{2+}$ and $Mn^{2+}$ ions exhibited negative effect. Especially, $Fe^{2+}$ and $Cu^{2+}$ ions almost completely suppressed the activity. Four extracellular autolysins of 30, 32, 38 and 41 kDa were detected in renaturing SOS-PAGE gel containing 0.2% heat-killed Micrococcus luteus cells as substrate. Among these 4 autolysins, 2 enzymes of 32 and 41 kDa distributed in the culture medium throughout the experimental time, but the 38 kOa enzyme diminished and 30 kOa began to appear at mid-exponential growth phase. When SOS-insoluble peptidoglycan of M. luteus was treated with the autolysins of Moraxella sp. CK-l, the concentration of free amino groups in reaction mixture increased. This indicates that the autolysins are N-acetylmuramyl-L-alanine amidase or endopeptidase.