• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.859-865
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• 2003

Surfactin is a mixture of cyclic lipopeptides built from variants of a heptapeptide and a ${\beta}-hydroxy$ fatty acid produced by several strains of Bacillus sp. Surfactin isoforms produced by endophytic Bacillus sp. CY22 from a balloon flower were isolated and characterized. It was found that the purified surfactin had three isoforms with protonated masses of m/z 1,008, 1,022, and 1,036, and different structures in combination with Na, K, Ca ions using MALDI-TOF MS, ESI-MS/MS, and ICP MS, respectively. In the MS/MS analysis, the isolated surfactin had the identical amino acid sequence (LLVDLL) and hydroxy fatty acids (with 13 to 15 carbons in length), even though isolated from different Bacillus strains. The sfp22 gene, required for producing the surfactin, consisted of an open reading frame (ORF) of 675 bp encoding 224 amino acid residues with a signal peptide of 20 amino acids. The predicted amino acid sequence of sfp22 was very similar to that of Ipa-8.

• Reproductive and Developmental Biology
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• v.37 no.4
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• pp.255-261
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• 2013

To profile the proteome in porcine plasma, blood samples were collected from adult male barrows and those plasma were retrieved. For the depletion or pre-fractionation of high-abundance proteins, plasma samples were treated with commercial kits. Then, protein profiling was initiated using one and two-dimensional electrophoresis. Proteins were spotted and then identified by MALDI-TOF-TOF and LC-MS-MS. In the results, more than forty six proteins were identified and the reference map was constructed. The pre-treatment for the removal of high-abundance proteins caused the changes in 2-DE images and some of the proteins were newly uncovered after the most of high abundant proteins were removed. However, it is expected for further steps necessary to identify more low-abundance proteins that may contain potential bio-markers.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.72-76
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• 2007

In order to examine the biofunctions of glycosylceramide which is representative of sphingolipid, monoglycosylceramide (cerebroside) was isolated from rice bran extract. Crude glycosylceramides were isolated in large quantities and promptly by flash system column chromatography from rice bran extract, and purified by normal-phase HPLC using an evaporative light-scattering detector. One major cerebroside was obtained by HPLC used as an eluent consisting of chloroform, methanol and water (99:11:1, v/v/v), and the constituents were analyzed by MALDI/TOF-MS, FAB-MS, GC and 600 MHz $^1$H-NMR. The component sugar was estimated to be glucose. In the ceramide, the fatty acid component consist was 2-hydroxy arachidic acid. The long-chain base component was sphinga-4,8-dienine.

• Mass Spectrometry Letters
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• v.2 no.2
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• pp.53-56
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• 2011

[ $C_8$ ]functionalized magnetic nanoparticles were synthesized by coating magnetic $Fe_3O_4$ nanoparticles with silicaamine groups using 3-aminopropyltriethoxysilane and by subsequently modifying the amine groups with chloro(dimethyl)octylsilane to produce octyl groups on the surface of the MNPs. The $C_8$-functionalized MNPs were used to enrich peptides from tryptic protein digests of myoglobin and ${\alpha}$-casein. The enriched peptides were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). MALDI-MS was also used to investigate desalting of the $C_8$-functionalized MNPs. Sample solutions were prepared in 1.0 M NaCl, and the successful removal of salt was observed. Enrichment with $C_8$-functionalized MNPs was very effective for separating and concentrating tryptic peptides.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.477-482
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• 2011

The structural analysis of polytrimethylene terephthalate (PTT) and characterization of the hydrolytic degradation products after acid hydrolysis were performed using MALDI-TOF mass spectrometry. Mass spectra of the PTT samples were analyzed using a self-calibration method as well as an internal calibration method with standard materials of known masses. PTT structures constituting the samples were determined from the analyses of the spectra, and their relative compositions were estimated. The MALDI-TOF mass spectra of the acid-hydrolyzed PTT sample showed three main series of oligomer products with different end groups in accordance with the hydrolysis schemes. From the spectra of both $Na^+$ and $K^+$ adducts, it was concluded that the PTT samples have higher affinity for $Na^+$ compared with $K^+$ and therefore show higher ionization efficiency with sodium ions when dithranol is used as a matrix. Two different wavelength laser beams ($\lambda$ = 337 nm and 355 nm) were tested and it was observed that the 355 nm beam was more efficient in obtaining the MALDI spectra of PTT using dithranol as a matrix under our experimental conditions.

• Macromolecular Research
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• v.16 no.2
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• pp.108-112
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• 2008

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis of nonpolar polymeric materials is affected by the sample preparation as well as the matrix and cationizing agent. This study examined the influence of silver salt types on the MALDI analysis of polybutadiene (PB). Silver trifluoroacetate (AgTFA), silver benzoate (AgBz), silver nitrate ($AgNO_3$), and silver p-toluenesulfonate (AgTS) were used as the silver salts to compare the MALDI mass spectra of PB. The mixture solution of PB and 2,5-dihydroxybenzoic acid (DHB), as a matrix dissolved in THF, was spotted on the sample plate and dried. A droplet of the aqueous silver salt solution was placed onto the mixture. The mass spectrum with AgBz showed the clear $[M+Ag]^+$ ion distribution of PB while the mass spectrum with AgTFA did not show $[M+Ag]^+$ ions but only silver cluster ions. The mass spectra with $AgNO_3$ and AgTS did not show a clear $[M+Ag]^+$ ion distribution. The difference in the formation of $[M+Ag]^+$ ions of PB depending on the silver salts was attributed to the silver cation transfer reaction between the silver salt and the matrix (DHB). The mass spectrum showed a clear $[M+Ag]^+$ ion distribution of PB when the conjugate acid of the silver salt was less acidic than the matrix.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.37-38
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• 2004

Salmonella gallinarum is a pathogen that is capable of causing disease in Korean native chicken. Although Salmonella gallinarum is important world-wide pathogens of poultry, little is understood of the mechanisms of pathogenesis of Salmonella gallinarum in the chicken. This study was to investigate chicken liver proteins affected by infection of Salmonella gallinarum in Korean native chicken. The differentially expressed proteins of chicken livers were identified by using 2-dimensional electro- phoresis (2D-E) and mass spectrometry (MS). We detected more than 300 protein spots on silver stained 2D gels using pH 3∼10 gradients. Three differentially expressed protein spots were analyzed by MALDI-TOF MS and MS/MS. The obtained MS and MS/MS data were searched against a protein database using the Mascot search engine. Further researches on the identified proteins can give valuable information of mechanism of pathogenesis in chicken.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.207-217
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• 2007

The Saccharomyces0 cerevisiae KNU5377 strain, which was isolated from spoilage in nature, has the ability to convert biomass to alcohol at high temperatures and it can resist against various stresses [18, 19]. In order to understand the defense mechanisms of the KNU5377 strain under menadione (MD) as oxidative stress, we used several techniques for study: peptide mass fingerprinting (PMF) by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) followed by two-dimensional (2D) gel electrophoresis, liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), and surface-enhanced laser desorption ionization-time of flight (SELDI-TOF) technology. Among the 35 proteins identified by MALDI-TOF MS, 19 proteins including Sod1p, Sod2p, Tsa1p, and Ahp1p were induced under stress condition, while 16 proteins were augmented under normal condition. In particular, five proteins, Sod1p, Sod2p, Ahp1p, Rib3p, Yaf9p, and Mnt1p, were induced in only stressed cells. By LC-ESI-MS/MS analysis, 37 proteins were identified in normal cells and 49 proteins were confirmed in the stressed cells. Among the identified proteins, 32 proteins were found in both cells. Five proteins including Yel047cp and Met6p were only upregulated in the normal cells, whereas 17 proteins including Abp1P and Sam1p were elevated in the stressed cells. It was interesting that highly hypothetical proteins such as Ynl281wp, Ygr279cp, Ypl273wp, Ykl133cp, and Ykr074wp were only expressed in the stressed cells. SELDI-TOF analysis using the SAX2 and WCX2 chips showed that highly multiple-specific protein patterns were reproducibly detected in ranges from 2.9 to 27.0 kDa both under normal and stress conditions. Therefore, induction of antioxidant proteins, hypothetical proteins, and low molecular weight proteins were revealed by different proteomic techniques. These results suggest that comparative analyses using proteomics might contribute to elucidate the defense mechanisms of KNU5377 under MD stress.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.74-76
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• 2006

닭의 간은 해독작용, 당의 저장, 혈장 단백질의 합성 등 주요 기능을 하는 것으로 알려져 있다. 본 연구는 간에서 성장 단계별로 발현량에 차이를 보이는 단백질들을 비교해 보았다. 2차원적 전기 영동에 의해 분리된 300개 이상의 단백질들이 확인되었으며 이 중 성장 단계별 특이적인 13개의 단백질은 MALDI-TOF MS에 의하여 분석이 되어졌다. 본 연구를 통하여 밝혀진 단백질들은 생화학적인 연구에 중요한 자료를 제공할 것으로 사료된다.

• YAKHAK HOEJI
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• v.43 no.4
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• pp.423-428
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• 1999

Two polysaccharides, ACP-UMP and ACP-ULF, were purified from the aerial part of Artemisia capillaris by anion-exchange chromatography, ultrafiltration, and gel filtration chromatography. The polysaccharides appeared to be homogenious from the results of HPLC. The molecular weights of ACP-UMF and ACP-ULF were estimated to be 16305.92 D and 3292.26 D, respectively, by MALDI-TOF MS. The sugar compositions were determined by GC to be arabinose 10.05%, xylose 1.67%, mannose 5.45G, galactose 39.06%, glucose 15.43% for ACP-UMF and arabinose 11.60%, xylose 11.15%, mannose 6.37% galactose 32.47%, glucose 18.35% for ACP-ULF. A polysaccharide, SP-M was determined to be 2462.52 D by MALDI-TOF MS. SP-M consisted mainly of rhamnose 36.49%, arabinose 29.00%, and glucose 19.38%. Incubation of CCl4-intoxicated hepatocytes with ACP-UMF reduced the levels of glutamic pyruvic transaminase (GPT) and cellular malondialdehyde (MDA) to 62.8% and 23.8%. ACP-ULF also reduced the levels of GPT and MDA to 46.1% and 38.1% and 26.3%, respectively.