• Journal of Pharmaceutical Investigation
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• 제7권1_4호
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• pp.1-12
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• 1977

Free amino acid in ethanol extracts and total amino acid hydrolysates of Coicis semen were analyzed by amino acid autoanalyzer. The sample A (unpolished Coicis Semen) and sample B(polished Coicis Semen) are used in this experiments. The results obtained from this study are as follows: 1) 17 kinds of free amino acid (Asp, Thr, Ser, Glu, Pro, Gly, Ala, Val, Cys, Met, Ileu, Lew, Try, Phe, Lys, His, Arg,) including 7 kinds of essential amino acid (Val, Lew, Ileu, Thr, Lys, Met, Phe,) as human nutrition were identified and quantified but tryptophan. 2) Total free amino acids of sample A is more than about 3 folds that of sample B. 3) The distribution of free amino acids contained in sample A, threonine is the richiest and then comes Ala, Glu, Asp, and Pro, in that order. In sample B, glutamic acid is the richiest and then comes Thr, Asp, Ala, and Gly, in that order. 4) 17 kinds of total amino acid (Asp, Thr, Ser, Glu, Pro, Gly, Ala, Val, Cys, Met, Ileu, Lew, Tyr, Pher, Lys, including 7 kinds of essential amino acid (Val, Leu, Ileu, Thr, Lys, Met, Phe,) in human nutrition except tryptophan were identified and quanified. 5) Total amino acid content of sample A is more than about 1.06 folds that of sample B. 6) Total amino acid content of sample A in acid hydrolysates is more than about 1.06 folds that of sample B in acid hydrolysates. 7) Unknown chromatogram of ethanol extracts and acid hydrolysates of Coicis Semen were identified as Ornitine.

• The Korean Journal of Physiology and Pharmacology
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• 제20권2호
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• pp.177-183
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• 2016

We fortuitously observed a human neutrophil intracellular free-calcium concentration ($[Ca^{2+}]_i$) increasing activity in the commercially available phosphodiesterase I (PDE I), which is actually dried crude venom of Crotalus atrox. As this activity was not observed with another commercially available pure PDE I, we tried to find out the causative molecule(s) present in 'crude' PDE, and identified Lys49-phospholipase A2 (Lys49-PLA2 or K49-PLA2), a catalytically inactive protein which belongs to the phospholipase A2 family, by activity-driven three HPLC (reverse phase, size exclusion, reverse phase) steps followed by SDS-PAGE and LC-MS/MS. K49-PLA2 induced $Ca^{2+}$ influx in human neutrophils without any cytotoxic effect. Two calcium channel inhibitors, 2-aminoetoxydiphenyl borate (2-APB) ($30{\mu}M$) and SKF-96365 ($20{\mu}M$) significantly inhibited K49-PLA2-induced $[Ca^{2+}]_i$ increase. These results suggest that K49-PLA2 modulates $[Ca^{2+}]_i$ in human neutrophils via 2-APB- and SKF-96365-sensitive calcium channels without causing membrane disruption.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.45-45
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• 1999

Cytochrome c (cyt c) binds to acidic membranes at low ionic strength. Replacement of Lys-72 or Lys-87 by Glu reduced the binding affinity of cyt c toward large unilamellar vesicles (LUV) in liquid crystalline phase. The differences were smaller for LUV in gel phase. A fraction of bound cyt c was non-electrostatically associated.(omitted)

• 생명과학회지
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• 제22권1호
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• pp.7-15
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• 2012

이전 연구에서 Streptomyces sp. M3 균주로부터 polyguluronate에 기질특이성을 가지는 알긴산분해효소를 cloning하고 활성을 연구하였다. 이번 연구에서는 pColdI vector에 들어있는 M3 알긴산분해효소 유전자를 돌연변이시켜 알긴산분해효소의 활성을 증진시키고자 하였으며, 점-돌연변이 또는 무작위-돌연변이 방법을 사용하여 돌연변이를 실시하였다. Ser25Arg, Phe99Leu, Asp142Asn, Val163Ala, Lys191Glu 및 Gly194Cys 등 6 종류의 돌연변이 단백질을 얻을 수 있었다. Phe99Leu 및 Lys191Glu 돌연변이 단백질은 알긴산을 분해하는 능력을 완전히 잃었으나 Gly194Cys 돌연변이 단백질의 활성은 원래 단백질에 비하여 10배 증가하였다. 또한 돌연변이된 M3 알긴산분해효소 단백질의 3차 구조는 Swiss-Model 자동모델러를 이용하여 생성하였으며 다른 알긴산분해효소의 결정구조와 비교하였다. 194 번째 아미노산인 글리신은 알긴산의 C-말단 보존서열인 YFKAGXYXQ의 Gly193과 Tyr195 사이에 위치한다. 이 연구에서 돌연변이된 글리신과 페닐알라닌 잔기들은 활성자리로부터 많이 떨어져있음에도 불구하고 돌연변이에 의하여 알긴산 분해활성이 강하게 영향을 받는 것으로 나타났다.

• 한국축산식품학회지
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• 제36권4호
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• pp.487-493
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• 2016

The antimicrobial activity of bovine lactoferrin hydrolysates (bLFH) was measured against Pseudomonas strains (P. syringae and P. fluorescens) in vitro. To compare susceptibility to bLFH, minimal inhibitory concentration (MIC) values were determined using chemiluminescence assays and paper disc plate assays. Antimicrobial effect against P. fluorescens was not observed by either assay, suggesting that bLFH did not exhibit antimicrobial activity against P. fluorescens. However, a significant inhibition of P. syringae growth was observed in the presence of bLFH. The addition of bLFH in liquid or solid medium inhibited growth of P. syringae in a dose-dependent manner. Furthermore, a bLFH peptide with antimicrobial activity toward P. syringae was isolated and identified. The N-terminal amino acid sequences of thus obtained antimicrobial bLFH peptides were analyzed by a protein sequencer and were found to be Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala and Phe-Lys-Cys-Arg-Arg-Trp-Gln-Trp-Arg-Met. The latter peptide sequence is known to be characteristic of lactoferricin. Therefore, in the present study, we identified a new antimicrobial peptide against P. syringae, present within the N-terminus and possessing the amino acid sequence of Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala.

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1459-1464
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• 2004

The purpose of this research was to investigate the potential use of cheese whey protein (CWP), a cheese by-product. The physiological activity of calcium-binding peptides in CWP may be used as a food additive that prevents bone disorders. This research also examined the characteristics of calcium-binding peptides. After the CWP was heat treated, it was hydrolyzed by trypsin. Then calcium-binding peptides were separated and purified by ion-exchange chromatography and reverse phase HPLC, respectively. To examine the characteristics of the purified calcium-binding peptides, amino acid composition and amino acid sequence were analyzed. Calcium-binding peptides with a small molecular weight of about 1.4 to 3.4 kDa were identified in the fraction that was flowed out from 0.25 M NaCl step gradient by ion-exchange chromatography of tryptic hydrolysates. The results of the amino acid analysis revealed that glutamic acid in a calcium-binding site took up most part of the amino acids including a quantity of proline, leucine and lysine. The amino acid sequence of calcium-binding peptides showed Phe-Leu-Asp-Asp-Asp-Leu-Thr-Asp and Ile-Leu-Asp-Lys from $\alpha$-LA and Ile-Pro-Ala-Val-Phe-Lys and Val-Tyr-Val-Glu-Glu-Leu-Lys from ${\beta}$-LG.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
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• pp.322-325
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• 2004

Kefir에서 유산균인 Lactobacillus acidophilus와 Lactococcus lactis 그리고 효모인 Candida kefir를 분리하였고, 이를 이용하여 FM(Fermented milk) A, B, C 제조${\cdot}$분석하였다. 유산균 수는 FM B가 $8.6{\times}\;10^9\;cfu/ml$로 가장 많았고, 효모수는 FM C가 $1.3{\times}\;10^7cfu/ml$로 가장 많았다. 알콜 함량은 FM C가 3.2%, FM A가 0.98%, FM B가 0.15% 였다. 아미노산은 FM A에서는 Glu, Pro, Leu, Lys, Asp 등이, FM B에서는 Glu, Leu, Pro, Lys 등이, FM C에서는 Glu, Leu, Pro, Lys 등이 주요 아미노산으로 나타났다. 지방산은 FM A, FM B, FM C 모두 palmitic acid(Cl6:0)와 oleic acid(Cl8:1)가 각각 33.5${\sim}$37.7%와 22.1${\sim}$22.4%의 수준으로 주요 지방산을 차지하였다. 관능검사 결과FM C가 가장 높은 점수를 받았으며, 다음은 FM A, FM B 순이었다.

• Biomolecules & Therapeutics
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• 제5권1호
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• pp.53-58
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• 1997

$[Lys^7$]dermorphin, abbreviated K7DA, which has structural features similar to a metabolically stable $\mu$-opioid peptide agonist $[D-Arg^2, Lys^4$]dermorphin analogue (DALDA), but is intrinsically more potent with respect to binding to the $\mu$-opioid peptide receptor. The present studies report on attempts to enhance brain uptake of systemically administered K7DA by conjugation to a complex of streptavidin (SA) and the OX26 murine monoclonal antibody to the rat transferrin receptor, which undergoes receptor-mediated transcytosis through the blood-brain barrier (BBB). SA-OX26 conjugate mediates BBB transport of biotinylated therapeutics. The K7DA is monobiotinylated at the $\varepsilon$-amino group of the $[Lys^7$] residue with cleavable linker using NHS-SS-biotin. The brain uptake of $^{125}I$ labeled biotinylated K7DA ($^{125}I$-bio-SSa-K7DA) was very small and rapidly metabolized after intravenous injection. The brain uptake, expressed as percent of injected dose delivered per gram of brain, of the $^{125}I$-bio-55-K7DA bound to the SA-OX26 conjugate $^{125}I$-bio-SS-K7DA/SA-OX26) was 0.14$\pm$0.01, a level that is 2-fold greater than the brain uptake of morphine. The cleavability of the disulfide linker in vivo in rat plasma and brain was assessed with gel filtration HPLC and intravenous injection of labeled opioid chimeric peptides. The disulfide linker is stable in plasma in vivo but is cleaved in rat brain in vivo. In conclusion, these studies show that delivery of these potential opioid peptides to the brain may be improved by coupling them to vector-mediated BBB drug delivery system.

• Biodesign
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• 제6권4호
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• pp.84-91
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• 2018

Spo0F is a response regulator that modulates sporulation, undergoes phosphorylation for phosphorelay signal transduction, and interacts with various regulatory proteins; however, the mechanisms through which phosphorylation induces structural changes and regulates interactions with binding partners remain unclear. Here, we determined the unphosphorylated crystal structure of Spo0F from the psychrophilic bacterium Paenisporosarcina sp. TG-14 (PaSpo0F) and established a phosphorylation-state structural model. We found that PaSpo0F underwent structural changes (Lys54 and Lys102) by phosphorylation and generated new interactions (Lys102/Gln10 and Lys54/Glu84) to stabilize the ${\beta}4/{\alpha}4$ and ${\beta}1/{\alpha}1$ loop structures, which are important target-protein binding sites. Analysis of Bacillus subtilis Spo0 variants revealed movement by BsSpo0F Thr82 and Tyr84 residues following interaction with BsSpo0B, providing insight into the movement of corresponding residues in PaSpo0F (Thr80 and Tyr82), with further analysis of BsSpo0F/BsRapH interaction revealing alterations in the ${\beta}4/{\alpha}4$ loop region. These results suggest that phosphorylation-induced structural rearrangement might be essential for PaSpo0F activation and expand the understanding of Spo0F-specific activation mechanisms during sporulation.

• 한국자기공명학회논문지
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• 제19권2호
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• pp.54-60
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• 2015

Papiliocin, from the swallowtail butterfly, Papilio xuthus, shows high bacterial cell selectivity against Gram-negative bacteria. Recently, we designed a 22mer analog with N-terminal helix from $Lys^3$ to $Ala^{22}$, PapN. It shows outstanding antimicrobial activity against Gram-negative bacteria with low toxicity against mammalian cells. In this study, we determined the 3-D structure of PapN in 300 mM DPC micelle using NMR spectroscopy and investigated the interactions between PapN and DPC micelles. The results showed that PapN has an amphipathic ${\alpha}$-helical structure from $Lys^3$ to $Lys^{21}$. STD-NMR and DOSY experiment showed that this helix is important in binding to the bacterial cell membrane. Furthermore, we tested antibacterial activities of PapN in the presence of salt for therapeutic application. PapN was calcium- and magnesium-resistant in a physiological condition, especially against Gram-negative bacteria, implying that it can be a potent candidate as peptide antibiotics.