• Mass Spectrometry Letters
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• v.12 no.2
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• pp.41-46
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• 2021

Collision-induced dissociation (CID) and higher-energy collisional dissociation (HCD) are the widely used fragmentation technique in mass spectrometry-based proteomics studies. Understanding the fragmentation pattern from the tandem mass spectra using statistical methods helps to implement efficient spectrum analysis algorithms. The study characterizes the frequency of occurrence of multi-charged fragment ions and their neutral loss events of doubly and triply charged peptides in the CID and HCD spectrum. The dependency of the length of the fragment ion on the occurrence of multi-charged fragment ion is characterized here. Study shows that the singly charged fragment ions are generally dominated in the doubly charged peptide spectrum. However, as the length of the product ion increases, the frequency of occurrence of charge 2 fragment ions increases. The y- ions have more tendencies to generate charge 2 fragment ions than b- ions, both in CID and HCD spectrum. The frequency of occurrence of charge 2 fragment ion peaks is prominent upon the dissociation of the triply charged peptides. For triply charged peptides, product ion of higher length occurred in multiple charge states in CID spectrum. The neutral loss peaks mostly exist in charge 2 states in the triply charged peptide spectrum. The b-ions peaks are observed in much less frequency than y-ions in HCD spectrum as the length of the fragment increases. Isotopic peaks are occurred in charge 2 state both in doubly and triply charged peptide's HCD spectrum.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.619-623
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• 2007

Synthesis of 4-substituted 3-exo-methylenechroman derivatives was carried out by the n-Bu3SnH-mediated vinyl radical cyclization as the key step starting from various salicylaldehydes.

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1387-1394
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• 2020

Clam worms (Marphysa sanguinea) are a rich source of bioactive components such as the antibacterial peptide, perinerin. In the present study, we explored the physiological activities of a novel NCWPFQGVPLGFQAPP peptide (NCW peptide), which was purified from clam worm extract through high-performance liquid chromatography. Tandem mass spectrometry (MS/MS) revealed that NCW was a new peptide with a molecular weight of 1757.86 kDa. Moreover, NCW peptide exhibited significant antioxidant effects, causing a 50% inhibition of DPPH radical at a concentration of 20 μM without showing any cytotoxicity. These were associated with a reduction in the activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) in LPS-stimulated RAW264. 7 cells. Furthermore, NCW peptide exhibited anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages via inhibition of the abnormal production of pro-inflammatory cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). These anti-inflammatory effects of NCW peptide were associated with the inhibition of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Our results therefore suggest that this novel NCW peptide with antioxidant and anti-inflammatory effects could be a good therapeutic agent against inflammation-related diseases.

• Journal of Korean Biological Nursing Science
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• v.3 no.2
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• pp.91-103
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• 2001

The bone is composed of the bone matrix of collagen and hydroxyapatite, the mixture of calcium and phosphours. The bone tissue is considered to the special connective tissue that possesses extracellular matrix made by collagen fiber deposited with mineral complex. In order to maintain bone mass measured by the sum of bone matrix and hydroxyapatite, bone resorption by osteoclast during lifetime and bone remodeling to form bone by osteoblast in its resorption region repeat continuously. The osteoblast has a mesodermic fetal origin like fibroblast for the formation of form tissues. Two cells express identical genes and synthesize the identical collagen type I as the major component of the formation of bone matrix and skin. Therefore, it is considered that the decrease of skinfold thickness and the decrease of bone mass related to the age, the change of two tissues composed of collagen type I is caused by the same genetic mechanism. The decrease of bone mass is caused by the change of the amount and structure of bone matrix by several factors and the amount of minerals deposited on bone matrix. Especially, in case of female, the deficiency of estrogen by menopause makes these changes rapidly increased. The decrease of bone mass and skinfold thickness is due to the decrease of the amount of collagen and its structural change the common component of bone tissue and skin tissue. Therefore, the relationship of the amount of cross-linked peptide N-telopeptide, collagen metabolite which excretes as urine. Based upon the proved results about the significant relationship of bone mass, the amount of bone collagen, the amount of skin collagen and skinfold thickness, the bone mass may be expected through a facile determination of skinfold thickness.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.426-428
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• 2012

In order to identify proteins that are present in biological samples, these samples are separated and analyzed under the sequential procedure as follows: protein purification and digestion, peptide fragmentation by tandem mass spectrometry (MS/MS) which breaks peptides into fragments, peptide identification, and protein identification. One of the widely used methods for protein identification is based on probabilistic approaches such as ProteinProphet and BaysPro. However, they do not consider the difference in peptide identification probabilities according to their length. Here, we propose a probabilistic graphical model-based approach to protein identification from MS/MS data considering peptide identification probabilities, number of sibling peptides, and peptide length. We compared our approach with ProteinProphet using a yeast MS/MS dataset. As a result, our model identified 27 more proteins than ProteinProphet at 1% of FDR (false discovery rate), confirming the importance of peptide length information in protein identification.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.282-286
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• 2010

To isolate a calcium-binding peptide from chlorella protein hydrolysates, chlorella protein was extracted and hydrolyzed using Flavourzyme, a commercial protease. The degree of hydrolysis and calcium-binding capacity were determined using trinitrobenzenesulfonic acid and orthophenanthroline methods, respectively. The enzymatic hydrolysis of chlorella protein for 6 hr was sufficient for the preparation of chlorella protein hydrolysates. The hydrolysates of chlorella protein were then ultra-filtered under 5 kDa as molecular weight. The membrane-filtered solution was fractionated using ion exchange, reverse phase, normal phase chromatography, and fast protein liquid chromatography to identify a calcium-binding peptide. The purified calcium-binding peptide had a calcium binding activity of 0.166 mM and was determined to be 700.48 Da as molecular weight, and partially identified as a peptide containing Asn-Ser-Gly-Cys based on liquid chromatography/electrospray ionization tandem mass spectrum.

• KSBB Journal
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• v.25 no.4
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• pp.395-400
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• 2010

Papain hydrolysate of fibroin was found to be mainly composed of several even-numbered peptides that can be produced at a large scale and can be used as a precursor for biological fine-chemicals such as peptide detergents. Thus, the hydrolysate was further modified to synthesize a peptide mixture of glyceryl esters using the identical enzyme for the production of such chemicals. Formation of glyceryl ester of each peptide was confirmed by identifying peaks of the nominal mass shift of +74 Da in mass spectrometry. Analysis of the mass spectra indicated that glyceryl esters of di- and tetra-peptides were the major constituents of the mixture and that alanylglycine was most preferentially esterified. It also suggests that papain prefers dipeptide to tetrapeptide and alanine to serine or tyrosine at $P_2$ position as substrate for glyceryl esterification. The glyceryl esters were recovered using ion exchange resin and the yield of glyceryl esterification recorded was 17.8% by weight.

• Mass Spectrometry Letters
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• v.9 no.2
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• pp.56-60
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• 2018

In this study, matrix-assisted laser desorption/ionization (MALDI) was applied to the TEMPO-assisted FRIPS for the first time. We found that 3-HPA is the optimal matrix for the analysis of p-TEMPO-Bz-Sc-peptides, which gives minimal precursor fragmentations. MALDI-TOF/TOF experiments on p-TEMPO-Bz-Sc-peptides yielded mainly $[a_n+H]^+$, $[z_n+H]^+$, and $[y_n]^+-type$ products, indicating that radical-driven peptide fragmentation occurs in MALDI-TOF/TOF-MS.

• Journal of Korean Biological Nursing Science
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• v.5 no.1
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• pp.5-12
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• 2003

The purpose of this study to compare of clinical profile between obese and nonobese type 2 diabetic patients. The subjects were consist of 111 obese (50 male, 61 female) and 159 non obese (79 male, 80 female) type 2 diabetic patients underwent fasting blood glucose, 2-hour postprandial blood glucose, $HbA_1c$, total cholesterol, triglyceride, high density lipoprotein, microalbuminuria, fasting C-peptide and 2-hour postprandial C-peptide were measured. Diabetes was diagnosed according to the American Diabetes Association (ADA) criteria. Obesity was defined as body mass index (BMI, kilograms per meters squared) ${\geq}23$. Data analyses were t-test, chisquare test in SAS program. The results were as follows : 1) Triglycerides and 2-hour postprandial C-peptide were significant higher in obese than non-obese patients. 2) Systolic blood pressure, Diastolic blood pressure, fasting blood sugar, 2-hour postprandial blood glucose, $HbA_1c$, total cholesterol, high-density lipoprotein, microalbuminuria and fasting C-peptide were no difference between obese and non-obese groups. These data indicate that obesity is a risk factor for the development of coronary heart disease (CHD) in diabetic patients. Therefore, weight reductions have beneficial effects on insulin action and glycemic control in obese type 2 diabetic patients.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.237-243
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• 2014

Human Glucagon like peptide-1 (GLP-1) is an incretin hormone that promotes secretion of insulin. In order to eliminate the formation of the soluble aggregate, Ala19 in GLP-1 was substituted with Thr, resulting in a GLP-1 mutant GLP-1A19T. The gene synthesis of GLP-1A19T and the fusion of 6-lysine tagged ubiquitin gene were accomplished by using the overlap extension polymerase chain reaction. The ubiquitin fused GLP-1A19T (K6UbGLP-1A19T) is expressed as form of inclusion body with little formation of the soluble aggregation in recombinant E. coli. In order to produce K6UbGLP-1A19T in large amounts, fed-batch fermentation was carried out in a pH-stat feeding strategy. Maximum dry cell weight of 87.7 g/L and 20.4% of specific K6UbGLP-1A19T content were obtained. Solid-phase refolding using a cation exchanger was carried out to renature K6UbGLP-1A19T. The refolded K6UbGLP-1A19T aggregated little and was released GLP-1A19T by on-column cleavage with ubiquitin-specific protease-1. The molecular mass of GLP-1A19T showed an accurate agreement with its theoretical molecular mass.