• Annals of Laboratory Medicine
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• 제38권6호
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• pp.530-537
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• 2018

Background: Measurement of insulin and C-peptide concentrations is important for deciding whether insulin treatment is required in diabetic patients. We aimed to investigate the analytical performance of insulin and C-peptide assays using the Lumipulse G1200 system (Fujirebio Inc., Tokyo, Japan). Methods: We examined the precision, linearity, and cross-reactivity of insulin and C-peptide using five insulin analogues and purified proinsulin. A method comparison was conducted between the Lumipulse G1200 and Roche E170 (Roche Diagnostics, Mannheim, Germany) systems in 200 diabetic patients on insulin treatment. Reference intervals for insulin and C-peptide concentrations were determined in 279 healthy individuals. Results: For insulin and C-peptide assays, within-laboratory precision (% CV) was 3.78-4.14 and 2.89-3.35%, respectively. The linearity of the insulin assay in the range of 0-2,778 pmol/L was $R^2=0.9997$, and that of the C-peptide assay in the range of 0-10 nmol/L was $R^2=0.9996$. The correlation coefficient (r) between the Roche E170 and Lumipulse G1200 results was 0.943 (P <0.001) for insulin and 0.996 (P <0.001) for C-peptide. The mean differences in insulin and C-peptide between Lumipulse G1200 and the Roche E170 were 19.4 pmol/L and 0.2 nmol/L, respectively. None of the insulin analogues or proinsulin showed significant cross-reactivity with the Lumipulse G1200. Reference intervals of insulin and C-peptide were 7.64-70.14 pmol/L and 0.17-0.85 nmol/L, respectively. Conclusions: Insulin and C-peptide tests on the Lumipulse G1200 show adequate analytical performance and are expected to be acceptable for use in clinical areas.

• Journal of Korean Biological Nursing Science
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• 제5권1호
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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.

• Applied Biological Chemistry
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• 제43권4호
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• pp.247-252
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• 2000

한국 전통장류의 기능성 탐색 연구의 일환으로 청국장 발효과정 중 고혈압을 유발하는 angiotensin converting enzyme(ACE)의 저해 peptide를 분리하고 저해효과를 검토하였다. 청국장은 Bacillus subtilis CH-1023을 이용하여 제조하였고, $20^{\circ}C,\;30^{\circ}C,\;40^{\circ}C,\;50^{\circ}C,\;60^{\circ}C$에서 $0{\sim}72$시간동안 배양하면서 protein양, protease activity, ACE 저해율을 측정하고 저해활성을 가지는 peptide를 정제 후 아미노산조성을 분석하였다. 청국장의 발효시간이 경과함에 따라 protein 함량이 증가하여 $40^{\circ}C$, 60시간에서 최대를 나타낸 후 감소하였으며, 발효시간에 따른 protease activity와 ACE 저해율은 $40^{\circ}C$, 60시간에서 최대로 나타난 후 점차 감소하였다. 따라서 Bacillus subtilis CH-1023을 이용한 청국장 제조는 $40^{\circ}C$에서 60시간 배양이 최적의 배양조건이었다. 최적 발효조건에 따라 청국장을 제조한 후 20 mM sodium phosphate buffer(pH 7.0)를 가해 추출한 추출물을 Amicon YM-3 membrane filtration과 Sephadex G-10, G-25를 이용한 gel filtration으로 부분정제 하였다. 또한 정제한 peptide는 첨가함량이 높아질수록 저해활성은 높게 나타났으며, 0.5 mg 정도의 peptide 함량으로 94.3%의 저해율을 나타내었다. 정제한 peptide의 아미노산 조성은 histidine, alanine, phenylalanine 함량이 높은 것으로 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권4호
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• pp.244-251
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• 2001

Over half of all biologically active peptide and peptide hormones are $\alpha$-amidated at their C-terminus, which is essential for their full biological activities. Amidation is accomplished through the sequential reaction of the two enzymes encoded by the single bifunctional, peptidyl-glycine $\alpha$-amidating monooxygenase (PAM or an $\alpha$-amidating enzyme). PAM catalyze the forma - tion of a peptide amide from peptide precursors that include a C-terminal glycine, and requires copper molecular oxygen and ascorbate. PAM is the only enzyme that produces peptide amides in vivo. However various strategies utilizing PAM, carboxypeptidase-Y enzymes, and chemical syn-thesis have been developed for producing peptide amides in vitro. The growing need and impor-tance of peptide amide drugs has highlighted the necessity for a efficient in vitro amidating sys-tem for industrial application for the production of peptide hormones, like calcitonin and oxytocin. This review presents the current situation regarding amidation with a special emphasis on the in-dustrial production or peptide hormones.

• Journal of Korean Biological Nursing Science
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• 제4권2호
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• pp.41-49
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• 2002

Aim To evaluate blood pressure, blood glucose and serum lipid level in obese and nonobese type 2 diabetic patients. Methods 206 obese(76 male, 130 female) and 442 nonobese(208 male, 234 female) type 2 diabetic patients underwent fasting blood glucose, 2-hour postprandial blood glucose, $HbA_1c$ total cholesterol, triglyceride, high density lipoprotein, microalbuminuria, blood urea nitrogen, creatinine and 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)${\geq}25$. Results In male, systolic blood pressure, triglycerides, microalbuminuria and C-peptide were significant higher in obese than nonobese patients. Fasting blood glucose were significantly lower in obese than nonobese patients. Diastolic blood pressure, 2-hour postprandial blood glucose, $HbA_1c$, total cholesterol, high density lipoprotein, blood urea nitrogen, and creatinine were no difference between 2 groups. In female, triglycerides and C-peptide were significant higher in obese than nonobese patients, Blood pressure, fasting blood glucose, 2-hour postprandial blood glucose, $HbA_1c$, total cholesterol, high density lipoprotein, microalbuminuria, blood urea nitrogen, and creatinine were no difference between 2 groups. Conclusion Our present study supports that increased triglycerides play a major role in increasing the risk of coronary heart disease(CHD) in obese women type 2 diabetic patients.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2001년도 추계학술대회
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• pp.97-101
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• 2001

The fusion between viral envelope and target cell membrane is a central step of viral infection, and the fusion proteins located at viral envelope mediate such process. Gp41 of HIV is one of the fusion proteins whose structure and mechanism of membrane fusion had been extensively studied. Functionally important motives of gp41 are the N-terminus fusion peptide, the coiled-coil and the membrane proximal C-peptide regions. The role of these regions during the fusion process had been thoroughly examined. Specially, insertion of the fusion peptide into membrane and conformational change of the coiled-coil and C-peptide regions are assumed to be critical for the fusion mechanism. In addition, the coiled-coil region has been shown to interact with membrane, and the C-peptide region regulates the interaction in a dose dependent manner. Furthermore, fusion defective mutations of the coiled-coil region dramatically changed its binding affinity to membrane. These results suggested that the membrane binding property of the coiled-coil region is important for the fusion activity of gp41, and such property could be modulated by the interaction with the C-peptide region.

• Mass Spectrometry Letters
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• 제4권4호
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• pp.71-74
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• 2013

In the present study, we report that the charge-directed (assisted) peptide dissociation products, such as b- and y-type peptide backbone fragments, were the major products in MS/MS and $MS^3$ applications of some o-TEMPO-Bz-C(O)-peptide ions, while radical-driven dissociation products, such as a/x and c/z-type fragments, were previously shown to be the major products in the free radical initiated peptide sequencing mass spectrometry (FRIPS MS). Those o-TEMPO-Bz-C(O)-peptides share a common feature in their sequences, that is, the peptides do not include an arginine residue that has the highest proton affinity among free amino acids. The appearance of b- and y-type fragments as major products in FRIPS MS can be understood in terms of the so-called "mobile-proton model". When the proton is highly mobilized by the absence of arginine, the chare-directed peptide dissociation pathways appear to be more competitive than the radical-driven dissociation pathways, in our FRIPS experiments.

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.79-84
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• 2015

A new cecropin-like antimicrobial peptide (Px-CLP) gene was isolated from the immunechallenged larvae of the swallowtail butterfly, Papilio xuthus, by employing annealing control primer (ACP)-based GeneFishing PCR. The full-length cDNA of Px-CLP is 310 nucleotides encoding a 70 amino acid precursor that contains a putative 22-residue signal peptide, a 4-residue propeptide, a presumed 37-residue mature peptide, and an uncommon 7-residue acidic pro-region at the C-terminus. The deduced amino acid sequence of Px-CLP showed significant identities with other Lepidopteran cecropin D type peptides. RT-PCR revealed that the Px-CLP transcript was detected at significant level after injection with bacterial lipopolysaccharide (LPS). The peptides with or without C-terminal acidic sequence region were synthesized on-solid phage and submitted to antibacterial activity assay. The synthetic 37-mer peptide (Px-CLPa), which removed C-terminal acidic sequence region, was showed exclusively antibacterial activity against E. coli ML35; meanwhile, a 44-mer peptide (Px-CLPb) with C-terminal acidic peptide region was not active. This result suggests that Px-CLP is produced as a larger precursor containing a C-terminal pro-region that is subsequently removed by C-terminal modification.

• Journal of Plant Biology
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• 제27권1호
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• pp.7-13
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• 1984

Activities of corn endosperm adenylate cyclase and phosphodiesterase were found right after germination, and phosphodiesterase activity was shown to increase steadily. Protease activity was also found. Corn peptide fraction purified by using Sephadex G-25 column was shown to enhance corn phosphodiesterase activity buy inhibit bovine phosphodiesterase activity. And the fraction inhibits corn adenylate cyclase activity. Trypsintreated peptide fraction was shown to enhance phosphodiesterase activity 80% compared to that of native peptide fraction. However, in case of DNase phosphodiesterase was shown to be innocuous. According to cumulative results, it is more likely that peptide fraction produced by protease inhibits adenylate cyclase activity and enhance phosphodiesterase, decreasing cAMP level.

• 농업과학연구
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• 제29권2호
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• pp.78-90
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• 2002

밀 단백질에 효소가수분해 할 때 생산되는 peptide의 항균활성과 천연항균제로서의 이용가능성을 검토하기 위하여 실험을 행하였다. 밀 단백질에 7종의 단백질가수분해효소를 작용시켜 생성된 가수분해물의 항균활성을 측정하고 한외여과, membrane filtration, HPLC를 이용하여 항균성 peptide를 분리 정제한 후 분자량과 아미노산 결합순서를 측정한 결과는 다음과 같다. 밀 단백질에 7종의 단백질 분해효소를 적용시켜 제조한 가수분해물중 Asp. saito protease를 적용시켜 얻어진 peptide 만이 항균활성을 나타내었다. Asp. saito protease는 $37^{\circ}C$, pH 6.0에서 작용시킨 경우에 항균활성이 가장 높았으며, $50^{\circ}C$ 이상에서는 활성을 나타내지 않았다. 밀단백 효소가수분해물은 membrane filtration에 의하여 분자량 1,000~3,000 에서 항균활성이 나타났다. Membrane filtration으로 얻어진 항균활성분획을 HPLC로 분리한 결과 retention time 31.1~31.8 min에서 항균활성을 나타내었다. 밀단백 효소가수분해물은 $121^{\circ}C$에서 15분간 가열하여도 효소활성이 유지되는 매우 안정한 화합물이었다. 항균활성분획을 MALDI-mass로 질량을 분석한 결과 1,633이었다. 항균성 peptide의 아미노산 결합순서는 cysteine, glycine, prolin, prolin, prolin, valine, valine, alanine, alanine, arginine 의 순서였다.