• Preventive Nutrition and Food Science
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• 제19권4호
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• pp.307-313
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• 2014

The effect of various levels of proteins, sulfates, and molecular weight ($M_w$) of a sulfated-glycoprotein ($NF_3$) from a sea cucumber, Stichopus japonicus, on nitric oxide (NO) releasing capacity from RAW 264.7 cells was investigated. The $NF_3$ derivatives had various amounts of proteins (4.8~11.2%) and sulfates (6.8~25.2%) as well as different $M_w$ ($640.3{\times}10^3{\sim}109.2{\times}10^3g/mol$). $NF_3$ was able to stimulate RAW 264.7 cells to release NO with lower protein contents, indicating that the protein moiety was not an important factor to stimulate macrophages. On the other hand, the NO inducing capacity was significantly reduced with decreased levels of sulfates and $M_w$, implying that sulfates and $M_w$ played a pivotal role in activating RAW 264.7 cells. It was not clear why sulfates and a certain range of $M_w$ were essential for stimulating macrophages. It appeared that certain levels of sulfates and $M_w$ of sulfated-glycoproteins were required to bind to the surface receptors on RAW 264.7 cells.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.874-880
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• 2010

A series of 13- and 14-membered cyclic enkephalin analogs based on the moderately $\mu$ selective prototype compound Tyr-C[D-$A_2bu$-Gly-Phe-Leu] 8a were synthesized to investigate the structure-activity relationship. The modifications of sequence were mainly focused on two positions 3 and 5, critical for the selective recognition for $\mu$ and $\delta$ opioid receptors. The substitution of hydrophobic $Leu^5$ with hydrophilic $Asp^5$ derivatives led to Tyr-C[D-$A_2bu$-Gly-Phe-Asp(N-Me)] 7 and Tyr-C[D-Glu-Phe-gPhe-rAsp(O-Me)] 5, the peptides with a large affinity losses at both $\mu$ and $\delta$ receptors. The substitution of $Phe^3$ with $Gly^3$ led to Tyr-C[D-Glu-Gly-gPhe-rLeu] 3 and Tyr-C[D-Glu-Gly-gPhe-D-rLeu] 4, the peptides with large affinity losses at $\mu$ receptors, indicating the critical role of phenyl ring of $Phe^3$ for $\mu$ receptor affinities. One atom reduction of the ring size from 14-membered analogs Tyr-C[D-Glu-Phe-gPhe-(L and D)-rLeu] 6a, 6b to 13-membered analogs Tyr-C[D-Asp-Phe-gPhe-(L and D)-rLeu] 1, 2 reduced the affinity at both $\mu$ and $\delta$ receptors, but increased the potency in the nociceptive assay, indicating the ring constrain is attributed to high nociceptive potency of the analogs. For the influence of D- or L-chirality of $Leu^5$ on the receptor selectivity, regardless of chirality and ring size, all cyclic diastereomers displayed marked $\mu$ selectivity with low potencies at the $\delta$ receptor. The retro-inverso analogs display similar or more active at $\mu$ receptor, but less active at $\delta$ receptor than the parent analogs.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.673-697
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• 2018

BACKGROUND: Cartilage tissue engineering (CTE) aims to obtain a structure mimicking native cartilage tissue through the combination of relevant cells, three-dimensional scaffolds, and extraneous signals. Implantation of 'matured' constructs is thus expected to provide solution for treating large injury of articular cartilage. Type I collagen is widely used as scaffolds for CTE products undergoing clinical trial, owing to its ubiquitous biocompatibility and vast clinical approval. However, the long-term performance of pure type I collagen scaffolds would suffer from its limited chondrogenic capacity and inferior mechanical properties. This paper aims to provide insights necessary for advancing type I collagen scaffolds in the CTE applications. METHODS: Initially, the interactions of type I/II collagen with CTE-relevant cells [i.e., articular chondrocytes (ACs) and mesenchymal stem cells (MSCs)] are discussed. Next, the physical features and chemical composition of the scaffolds crucial to support chondrogenic activities of AC and MSC are highlighted. Attempts to optimize the collagen scaffolds by blending with natural/synthetic polymers are described. Hybrid strategy in which collagen and structural polymers are combined in non-blending manner is detailed. RESULTS: Type I collagen is sufficient to support cellular activities of ACs and MSCs; however it shows limited chondrogenic performance than type II collagen. Nonetheless, type I collagen is the clinically feasible option since type II collagen shows arthritogenic potency. Physical features of scaffolds such as internal structure, pore size, stiffness, etc. are shown to be crucial in influencing the differentiation fate and secreting extracellular matrixes from ACs and MSCs. Collagen can be blended with native or synthetic polymer to improve the mechanical and bioactivities of final composites. However, the versatility of blending strategy is limited due to denaturation of type I collagen at harsh processing condition. Hybrid strategy is successful in maximizing bioactivity of collagen scaffolds and mechanical robustness of structural polymer. CONCLUSION: Considering the previous improvements of physical and compositional properties of collagen scaffolds and recent manufacturing developments of structural polymer, it is concluded that hybrid strategy is a promising approach to advance further collagen-based scaffolds in CTE.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.1931-1936
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• 2010

Discovery and isolation of compounds capable of blocking the interactions between VCAM-1 and VLA-4, a major pair of adhesion molecules contributing to the different steps of leukocyte migration across the endothelium in inflammatory responses, has been a major goal of this lab. Through bioactivity-guided fractionation, five saikosaponins were subsequently isolated from the methanol extracts of the roots of Bupleurum falcatum L. Their structures were elucidated by spectroscopic analysis ($^1H-$, $^{13}C$-NMR and 2D-NMR), as follows, saikosaponins: A (1); D (2); C (3); B3 (4); B4 (5). Compounds 1 and 2 inhibited interaction of sVCAM-1 and VLA-4 of THP-1 cells with respective $IC_{50}$ values of 7.8 and 1.7 ${\mu}M$. The aglycone structure of 2 also showed cell adhesion inhibitory activity with an $IC_{50}$ value of 21.1 ${\mu}M$. With these results, we suspect these two saikosaponins from the Bupleurum falcatum L. roots to be prime candidates for therapeutic strategies towards inflammation.

• Biomaterials and Biomechanics in Bioengineering
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• 제1권1호
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• pp.51-62
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• 2014

The purpose of this experiment was to evaluate the apatite-formation abilities of low-modulus Ti-7.5Mo substrates treated with NaOH aqueous solutions and subsequent ethyl alcohol aging before soaking them in simulated body fluid. Specimens of Ti-7.5Mo were initially treated with 5 M NaOH at $60^{\circ}C$ for 24 h, resulting in the formation of a porous network structure composed of sodium hydrogen titanate. Afterwards, the specimens were aged in ethyl alcohol at $60^{\circ}C$ for 5 or 10 min, and subsequently immersed in simulated body fluid at $37^{\circ}C$ for 3, 7 and 14 days. Ethyl alcohol aging significantly increased the apatite-forming abilities of Ti-7.5Mo. The amount of apatite deposited on the Ti-7.5Mo after NaOH treatment and subsequent ethyl alcohol aging was much greater, especially after the Ti-7.5Mo specimens were aged for 5 min. Due to its excellent combination of bioactivity, low elastic modulus and low processing costs, the Ti-7.5Mo treated with NaOH aqueous solutions and subsequently aged in ethyl alcohol has promising heavy load-bearing applications.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1076-1080
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• 2008

Glucagon, a peptide hormone produced by alpha-cells of Langerhans islets, is a physiological antagonist of insulin and stimulator of its secretion. In order to improve its bioactivity, we modified its structure at the C-terminus by amidation catalyzed by a recombinant amidase in bacterial cells. The human gene coding for glucagon-gly was PCR amplified using three overlapping primers and cloned together with a rat ${\alpha}$-amidase gene in plasmid pMGA. Both genes were expressed under control of the strong constitutive promoter of aph and secretion signal melC1 in Streptomyces lividans. With Phenyl-Sepharose 6 FF, Q-Sepharose FF, SP-Sepharose FF chromatographies and HPLC, the peptide was purified to about 93.4% purity. The molecular mass of the peptide is 3.494 kDa as analyzed by MALDI TOF, which agrees with the theoretical mass value of the C-terminal amidated glucagon. The N-terminal sequence of the peptide was also determined, confirming its identity with human glucagon at the N-terminal part. ELISA showed that the purified peptide amide is bioactive in reacting with glucagon antibodies.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7523-7527
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• 2013

Thymidylate synthase (TS) catalyzes the transfer of a methyl group from methylenetetrahydrofolate to dUMP to form dTMP. It is a primary target in the chemotherapy of colorectal cancers and some other neoplasms. In order to obtain pure protein for analysis of structure and biological function, an expression vector TS-pET28b (+) was constructed by inserting wild-type human thymidylate synthase (hTS) cDNA into pET28b (+). Then an expression strain was selected after transformation of the recombined plasmid into Rosetta (DE3). Fusion protein with His-tag was efficiently expressed in the form of inclusion bodies after IPTG induction and the content was approximately 40.0% of total bacteria proteins after optimizing expression conditions. When inclusion bodies were washed, dissolved and purified by Ni-NTA under denatured conditions, the purity was up to 90%. On SDS-PAGE and West-blotting, the protein band was found to match well with the predicted relative molecular mass-36kDa. Bioactivity was 0.1 U/mg. The results indicated that high-level expression of wild-type hTS cDNA can be achieved in prokaryotes with our novel method, facilitating research into related chemotherapy.

• 한국미생물·생명공학회지
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• 제45권3호
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• pp.209-217
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• 2017

In the enduring investigation of the bioactive microbes, Pseudomonas aeruginosa strain (referred to as CGK-KS-1 (ICTB-315)), isolated from Chumathang hot spring, Ladakh, and India, was identified to possess a major bioactive fraction with antimicrobial and anti-biofilm properties. This bioactive metabolite was purified through bioactivity-guided fractionation. The chemical structure of this major compound was elucidated as phenazine-1-carboxamide (PCN) based on $^1H$ and $^{13}C$ NMR, FT-IR, EI-HR-MS and 2D NMR spectroscopic techniques. In the current study, PCN exhibited antimicrobial activity with MIC values ranging between $1.9-3.9{\mu}g/ml$ against various test human pathogens and Xanthomonas spp. PCN showed the anti-biofilm property with the $IC_{50}$ values ranging from 17.04 to $60.7{\mu}M$ against different test pathogens. The in silico docking studies showed PCN strongly interacted with various proteins of different Xanthomonas spp. with high binding energies. We report herein for the first time the anti-biofilm property and the docking studies of PCN. The extrolite from P. aeruginosa strain CGK-KS-1 showed promising bioactivities and may be considered as a potential candidate for application in various biocontrol strategies.

• Advances in Traditional Medicine
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• 제6권4호
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• pp.355-360
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• 2006

Plants have been used in traditional medicinal system for centuries. Bangladeshi medicinal plants have received considerable attention from the researchers for evaluation of their bioactivity. As a part of our ongoing research of screening the Bangladeshi medicinal plants, the ethanolic extract of Dendrophthoe falcata have been chosen for the present study. The ethanolic extract of the leaves of the plant have been assessed for their antioxidant, antinociceptive, and general toxicity. The extract showed potent antioxidant activity ($IC_{50}5.1{\mu}g/ml$) using DPPH radical scavenging assay, which is comparable to the standard ascorbic acid ($IC_{50}4.6{\mu}g/ml$). The extract significantly and dose dependently inhibited the acetic acid induced writhing in mice (71.2%, P < 0.001 and 28.0%, P < 0.05 for 500 and 250 mg/kg body weight, respectively). A general toxicity was assessed by a simple and low cost assay using brine shrimp lethality as an indicator. The extract showed low level of toxicity ($LC_{50}100{\mu}g/ml$). Using different chromatographic techniques, quercitrin (quercetin 3-O-${\alpha}$-rhamnoside) was separated as the major component from the extract. The structure was elucidated by detailed 1D and 2D NMR and mass spectral analysis.

• 대한화학회지
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• 제52권1호
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• pp.36-46
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• 2008

가진 1차 arylselenocarboxylic amide의 고리화는 여러가지 새로운 2,4-diaryl-1,3-selenazoles에 사용되었다. 염소, 브롬, 요오드를 사용한 2,4-diaryl-1,3-selenazoles의 할로겐화는 좋은 수율의 새로운 1,1-dihalo-2,4-diaryl-1,3-selenazoles를 준다. AIDS virus(HIV-1 and HIV-2)에 대하여 몇몇의 1,1-dihalo-2,4-diaryl-1,3-selenazoles의 항바이러스 활성도를 검사하였다. 그것들은 HIV-1에 대한 약간의 대생물활성을 보였다. 모든 화합물은 원소분석, 1H NMR 그리고 질량 분광분석 정보로 구조분석 하였다. 2-(3,4-dimethoxyphenyl)-4-(4-bromophenyl)-1,3-selenazole의 결정구조도 보였다.