• Molecules and Cells
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• 제41권2호
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• pp.150-159
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• 2018

Animals use their odorant receptors to receive chemical information from the environment. Insect odorant receptors differ from the G protein-coupled odorant receptors in vertebrates and nematodes, and very little is known about their protein-protein interactions. Here, we introduce a mass spectrometric platform designed for the large-scale analysis of insect odorant receptor protein-protein interactions. Using this platform, we obtained the first Orco interactome from Drosophila melanogaster. From a total of 1,186 identified proteins, we narrowed the interaction candidates to 226, of which only two-thirds have been named. These candidates include the known olfactory proteins Or92a and Obp51a. Around 90% of the proteins having published names likely function inside the cell, and nearly half of these intracellular proteins are associated with the endomembrane system. In a basic loss-of-function electrophysiological screen, we found that the disruption of eight (i.e., Rab5, CG32795, Mpcp, Tom70, Vir-1, CG30427, Eaat1, and CG2781) of 28 randomly selected candidates affects olfactory responses in vivo. Thus, because this Orco interactome includes physiologically meaningful candidates, we anticipate that our platform will help guide further research on the molecular mechanisms of the insect odorant receptor family.

• Biomolecules & Therapeutics
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• 제1권2호
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• pp.143-150
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• 1993

The metabolic profile of triprolidine, 2-[(4-methylphenyl)-3-(1-pyrrolidinyl-1-propenyl)] pyridine, was determined. Urinary extracts obtained with enzyme hydrolysis were derivatized with MSTFA/TMSCl (N-methyl-N-trimethylsilyl trifluoroacetamide/trimethylchlorosilane) and analyzed by GC/MSD. In human urine, which were obtained after the oral administration with triprolidine, hydroxymethyltriprolidine, triprolidine carboxylic acid, oxotriprolidine carboxylic acid and unchanged triprolidine were detected. The maximum urinary excretion rate of triprolidine and hydroxymethyltriprolidine which were extracted from human urine was at 2 to 4 hours after the drug administration. Triprolidine and hydroxymethyl triprolidine were identified by comparison with authentic standards In chromatographic and mass spectral properties. Triprolidine carboxylic acid was detected as a major metabolite of its metabolites in the urine. Oxotriprolidine carboxylic acid and triprolidine carboxylic acid were tentatively identified by the interpretation of its mass spectral patterns. These data suggest that in human, hydroxylation of either the benzyl or pyrrolidine ring can occur during triprolidine elimination.

• Mass Spectrometry Letters
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• 제6권2호
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• pp.31-37
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• 2015

Phosphorylation upon protein is well known to a key regulator that implicates in modulating many cellular processes like growth, migration, and differentiation. Up to date, grafting of multidimensional separation techniques onto advanced mass spectrometry (MS) has emerged as a promising tool for figuring out the biological functions of phosphorylation in a cell. However, advanced MS-based phosphoproteomics is still challenging, due to its intrinsic issues, i.e., low stoichiometry, less susceptibility in positive ion mode, and low abundance in biological sample. To overcome these bottlenecks, diverse techniques (e.g., SCX, HILIC, ERLIC, IMAC, TiO₂, etc.) are continuously developed for on-/off-line enrichment of phosphorylated protein (or peptide) from biological samples, thereby helping qualitative/quantitative determination of phosphorylated protein and its phosphorylated sites. In this review, we introduce to the overall views of enrichment tools that are universally used to selectively isolate targeted phosphorylated protein (or peptide) from ordinary ones before MS-based phospoproteomic analysis.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.242-247
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• 2003

An experimental study presents characteristics of combustion in a combustion chamber by port deactivation valve for economy and emissions standards. In order to use combustion properties data it is necessary to build some data base, which use cylinder pressure sensor, etc. Port deactivation valve has been developed to satisfy requirement of achieving sufficient swirl generation to improve the combustion. A feasibility and necessity of combustion pressure based cylinder spark timing control has been examined. So, this was obtained the Coefficient of Variation(COV) and the mass-burned(MFB). The characteristics of pressure ratio fraction is similar to that of mass-burned fraction. Using the results of the test, the effects of the combustion chamber can be improved combustion stability by port deactivation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1993년도 추계학술대회논문집; 반도아카데미, 26 Nov. 1993
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• pp.29-34
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• 1993

In many circumstances, it is desired to move a mass from one position to another without inducing any vibration in the mass being moved. Two such problems are considered here: the motion of a pendulum initiated by the specified motion of its support. In each case, it is desired that the system start at rest and come to rest in the second position. A simple strategy for the specified motion is given here. The method is motivated by engine cam-follower design. The force required to move the system in question is determined as well as the maximum value of the force required (and the times at which these forces take place) is determined.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.159-162
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• 2021

The fragmentation pattern of four hindered phenol antioxidants was investigated using ammonium and lithium ions as the additives for ionization. Due to different binding geometries and interactions, they underwent different characteristic fragmentation reactions providing useful complementary information for structural analysis of hindered phenol antioxidants. Ammonium ion adducts were fragmented successively until all t-butyl groups were lost in the form of isobutylene and allowed the estimation of the number of t-butyl groups present in the molecule. Lithium ion adducts produced fragment ions from major backbone cleavage, on the other hand, which provide more crucial information for the identification of detailed backbone structure.

• 분석과학
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• 제26권6호
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• pp.401-406
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• 2013

유정란의 부화과정 동안 소모되는 산소와 배출되는 이산화탄소의 양을 기체질량분석기를 사용하여 측정하였다. 20 일에 걸친 유정란과 무정란의 인공부화 과정 동안 기체 시료를 채취하기 위해 밀폐된 구조의 시료 챔버를 제작하였다. 2~4 일 간격으로 시료 챔버 안에 유정란을 1 시간 동안 방치한 후, 실린지를 이용해 밀폐된 시료 챔버로부터 2 mL의 기체 시료를 채취한 후 기체질량분석기를 사용하여 분석하였다. 인공부화를 시작한 후 약 10 일 후부터 닭 배아의 산소 소모량과 이산화탄소 배출량이 급격히 증가하였다. 20 일 후에는 시간당 23 mL의 산소를 소모하고 16 mL의 이산화탄소를 배출하였다. 전체 부화 기간 동안 산소의 농도는 4.3 mol% 감소하였고 이산화탄소의 농도는 3.1 mole% 증가하여 소모된 산소의 몰수와 배출된 이산화탄소의 몰수가 같지 않았다. 한편, 동일한 기간 동안 질소의 농도는 약 1.3 mol% 증가하였으며 그 증가된 농도는 소모된 산소와 배출된 이산화탄소의 농도변화량의 차이와 비슷한 값을 보였다. 따라서 질소의 몰분율 증가는 소모된 산소와 배출된 이산화탄소 간의 몰분율 차이에 의한 것임을 알 수 있었다. 본 연구에서는 기체의 조성 변화량을 정확히 측정하여 유정란의 부화과정 중 호흡현상을 설명할 수 있었다.

• 분석과학
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• 제21권5호
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• pp.364-374
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• 2008

2000년도에 COMNAP/SCAR에 의해 극지지역의 환경모니터링에 관한 표준기술지침서인 'Antarctic Environmental Monitoring Handbook'이 발간되었다. 이 지침서에 따라 남극세종기지주변지역의 토양시료중의 중금속을 분석하였다. 시료분해방법은 고압산분해 방법을 사용하였고, 분석방법으로는 동위원소희석 유도결합플라스마질량분석법을 사용하여 토양중의 Pb, Cu, Zn 성분을 분석하였다. 분석방법의 정확성을 확인하기 위해 표준시료인 NIST 2702를 분석한 결과 인증값의 99.5~100.8% 범위내에서 일치하였다. Chelex 100 이온교환수지를 사용하여 간섭이온을 제거하기 위해 매질을 분리하였다. 측정결과 인위적오염이 예상되는 기지주변지역의 중금속의 평균농도는 각각 Pb 332.9 mg/kg, Cu 95.6 mg/kg, Zn 115.3 mg/kg로 나타났으며, 기지에서 멀리 떨어진 지역의 평균농도는 각각 Pb 28.1 mg/kg, Cu 101.8 mg/kg, Zn 115.6 mg/kg로 나타났다. Pb 농도는 기지주변지역과 멀리 떨어진 지점에서 현저한 차이를 보였다.

• Mass Spectrometry Letters
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• 제2권3호
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• pp.69-72
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• 2011

Defective synthesis of the steroid hormones by the adrenal cortex has profound effects on human development and homeostasis. Due to the time-consuming chromatography procedure combined with mass spectrometry, the matrix-assisted laser desorption ionization method coupled to the linear ion-trap tandem mass spectrometry (MALDI-LTQ-MS/MS) was developed for quantitative analysis of 10 adrenal steroids in human serum. Although MALDI-MS can be introduced for its applicability as a high-throughput screening method, it has a limitation on reproducibility within and between samples, which renders poor reproducibility for quantification. For quantitative MALDI-MS/MS analysis, the stable-isotope labeled internal standards were used and the conditions of crystallization were tested. The precision and accuracy were 3.1~35.5% and 83.8~138.5%, respectively, when a mixture of 10 mg/mL ${\alpha}$-cyano-4-hydroxycinnamic acid in 0.2% TFA of 70% acetonitrile was used as the MALDI matrix. The limit of quantification ranged from 5 to 340 ng/mL, and the linearity as a correlation coefficient was higher than 0.988 for all analytes in the calibration range. Clinical applications include quantitative analyses of patients with congenital adrenal hyperplasia. The devised MALDI-MS/MS technique could be successfully applied to diagnosis of clinical samples.

• 공업화학
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• 제16권3호
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• pp.323-327
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• 2005

Pentachlorophenol (PCP)은 독성이 강한 발암성 물질로 미국환경청(Environmental Protection Agency, USA)이 정한 대표적인 환경호르몬이다. 본 연구에서는 종이 중에 함유된 극미량의 PCP 측정을 목적으로 하였다. 종이의 전처리는 고상추출법(SPE)을 이용하였고 분석을 위해 PCP를 유도체화시켜 gas chromatography/mass spectroscopy-selected ion monitoring (GC/MS-SIM)으로 분석하였다. GC/MS-SIM의 분석 결과 실릴화 PCP의 분석감도가 증가되었다. 본 실험에서는 실험군으로 사무용지와 벽지를 사용하였다.