• Food Science and Biotechnology
• /
• 제16권5호
• /
• pp.807-811
• /
• 2007

Diabetes is marked by high glucose levels and is associated with decreased bone mass and increased fracture rates. To determine if [6]-gingerol could influence osteoblast dysfunction induced by 2-deoxy-D-ribose (dRib), osteoblastic MC3T3-E1 cells was treated with dRib and [6]-gingerol and markers of osteoblast function and oxidized protein were examined. [6]-Gingerol ($10^{-7}\;M$) significantly increased the growth of MC3T3-E1 cells in the presence of 30 mM dRib (p<0.05). [6]-Gingerol ($10^{-7}\;M$) caused a significant elevation of alkaline phosphatase (ALP) activity, collagen content, and osteocalcin secretion in the cells. We then examined the effect of [6]-gingerol on the production of osteoprotegerin and protein carbonyl in osteoblasts. Treatment with [6]-gingerol ($10^{-9}$ and $10^{-7}\;M$) increased osteoprotegerin secretion in osteoblastic cells. Moreover, [6]-gingerol ($10^{-9}$ and $10^{-7}\;M$) decreased protein carbonyl contents of osteoblastic MC3T3-E1 cells in the presence of 30 mM dRib. Taken together, these results demonstrate that [6]-gingerol inhibits dRib-induced damage and may be useful in the treatment of diabetes related bone diseases.

• Archives of Pharmacal Research
• /
• 제27권12호
• /
• pp.1275-1283
• /
• 2004

Fate of the nascent thyrolglobulin (Tg) molecule is characterized by multimerization. To establish the formation of Tg multimers, the partially unfolded/reduced Tg or deoxycholate-treated/ reduced Tg was subjected to protein disulfide isomerase (PDI)-mediated multimerization. Oxidized glutathione/PDI-mediated formation of multimeric Tg forms, requiring at least an equivalent molar ratio of PDI/Tg monomer, decreased with increasing concentration of reduced glutathione (GSH), suggesting the oxidizing role of PDI. Additional support was obtained when PDI alone, at a PDI/Tg molar ratio of 0.3, expressed a rapid multimerization. Independently, the exposure of partially unfolded Tg to GSH resulted in Tg multimerization, enhanced by PDI, according to thiol-disulfide exchange. Though to a lower extent, a similar result was observed with the dimerization of deoxycholate-pretreated Tg monomer. Consequently, it is implied that intermolecular disulfide linkage may be facilitated at a limited region of unfolded Tg. In an attempt to examine the multimerization site, the cysteine residue-rich fragments of the Tg were subjected to GSH-induced multimerization; a 50 kDa fragment, containing three vicinal dithiols, was multimerized, while an N-terminal domain was not. Present results suggest that the oxidase as well as isomerase function of PDI may be involved in the multimerization of partially unfolded Tg or deoxycholate-treated Tg.

• BMB Reports
• /
• 제28권6호
• /
• pp.477-483
• /
• 1995

The recombinant human interferon alpha 2a ($rhIFN-{\alpha}2a$), expressed in Saccharomyces cerevtsiae, was purified from insoluble aggregates. The inclusion body of $rhIFN-{\alpha}$ was solubilized by guanidine salt in the presence of disulfide reducing agent. The refolding of denatured $rhIFN-{\alpha}2a$ was achieved by simple dilution. The authentic interferon alpha, which has two correctly matched disulfide bonds, was seperated from incompletely oxidized $IFN-{\alpha}$ and dimeric $IFN-{\alpha}$ by use of a CM-Sepharose column, followed by size exclusion columns at two different pH conditions. The purified protein has been subjected to detailed physicochemical characterization including sequence determination. Unlike other $rhIFN-{\alpha}2a$ from E. coli reported, the $rhIFN-{\alpha}2a$ from S. cerevisiae has no methionine residue at its N-terminus originating from the start codon, ATG. The pI of the protein was determined to be 6.05 with a single band in the pI gel, which demonstrated that the purified $rhIFN-{\alpha}$ was homogeneous. The structural study using circular dichroism showed that the protein retains its three dimensional structure in the wide range of pH conditions between pH 3 and 9, and only minor strucural deformation was observed at pH 1.0.

• Molecules and Cells
• /
• 제37권11호
• /
• pp.819-826
• /
• 2014

Protein modifications of recombinant pharmaceuticals have been observed both in vitro and in vivo. These modifications may result in lower efficacy, as well as bioavailability changes and antigenicity among the protein pharmaceuticals. Therefore, the contents of modification should be monitored for the quality and efficacy of protein pharmaceuticals. The interface of EPO and its receptor was visualized, and potential amino acids interacting on the interface were also listed. Two different types of modifications on the interface were identified in the preparation of rHu-EPO BRP. A UPLC/Q-TOF MS method was used to evaluate the modification at those variants. The modification of the oxidized variant was localized on the Met54 and the deamidated variants were localized on the Asn47 and Asn147. The extent of oxidation at Met54 was 3.0% and those of deamidation at Asn47 and Asn147 were 2.9% and 4.8%, respectively.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제48권1호
• /
• pp.25-32
• /
• 2024

Soy protein isolate (SPI) has garnered researchers' attention due to its abundance, costeffectiveness, excellent biocompatibility, hemo-compatibility, and biodegradability. However, SPI faces limitations in application due to poor processability and weak mechanical strength. Substantial efforts have been made to address these challenges. In this preliminary study, glycerol and biofibers were added to SPI to improve the mechanical properties and film forming, and glyoxal was employed to crosslink SPI molecules. The microstructure and mechanical properties of the resulting SPI/composite films were evaluated. A 15% addition of glycerol proved sufficient for good film formation. Among the biofibers, short SF microfibers were the most effective in enhancing breaking strength, while TEMPO-oxidized CNF (cellulose nanofiber) excelled among CNFs. Crosslinking with glyoxal significantly enhanced the mechanical properties, with the type of biofiber minimally affecting the mechanical properties of the crosslinked SPI composite films.

• 한국자원식물학회지
• /
• 제30권2호
• /
• pp.133-143
• /
• 2017

와송 ethylacetate 분획추출물의 폴리페놀 함량은 $634.48{\mu}g/mg$, 플라보노이드 함량은 $205.20{\mu}g/mg$로 나타났다. 또한 항산화 활성을 보면, ethylacetate 분획추출물의 1 mg/ml 농도에서 DPPH radical, ABTS radical 소거능은 95% 이상으로, ascorbic acid의 97%의 소거능과 거의 유사한 결과를 보여 높은 항산화능을 확인할 수 있었다. 항산화효소 활성의 경우, APX 및 CAT 효소 활성은 $1125.89{\mu}mol$ ascorbate oxidized/min/mg protein, 119.87mmol $H_2O_2$ decomposed/min/mg protein 으로 높은 것으로 나타났다. 항균활성은 Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, Malassezia furfur 균주에서 항생제 kanamycin보다 큰 저해환을 형성하여 높은 항균력이 확인되었다. 또한 와송의 용매분획별 추출물의 인체암 세포주에 대한 세포증식억제 효과는 특히 ethylacetate 분획추출물에서 폐암, 유방암에 대해 높은 효과를 나타냈다. 이와 같은 결과들을 종합하면 와송의 ethylacetate 분획추출물을 이용한 천연 항산화제와, 천연 항균제로서의 개발 가치가 높은 것으로 기대되어 경제성 있는 천연소재가 될 것으로 사료된다.

• Journal of Microbiology and Biotechnology
• /
• 제27권5호
• /
• pp.983-989
• /
• 2017

NADPH-P450 reductase (NPR) transfers electrons from NADPH to cytochrome P450 and heme oxygenase enzymes to support their catalytic activities. This protein is localized within the endoplasmic reticulum membrane and utilizes FMN, FAD, and NADPH as cofactors. Although NPR is essential toward enabling the biochemical and pharmacological analyses of P450 enzymes, its production as a recombinant purified protein requires a series of tedious efforts and a high cost due to the use of $NADP^+$ in the affinity chromatography process. In the present study, the rat NPR clone containing a $6{\times}$ Histidine-tag (NPR-His) was constructed and heterologously expressed. The NPR-His protein was purified using $Ni^{2+}$-affinity chromatography, and its functional features were characterized. A single band at 78 kDa was observed from SDS-PAGE and the purified protein displayed a maximum absorbance at 455 nm, indicating the presence of an oxidized flavin cofactor. Cytochrome c and nitroblue tetrazolium were reduced by purified NPR-His in an NADPH-dependent manner. The purified NPR-His successfully supported the catalytic activities of human P450 1A2 and 2A6 and fungal CYP52A21, yielding results similar to those obtained using conventional purified rat reductase. This study will facilitate the use of recombinant NPR-His protein in the various fields of P450 research.

• KSBB Journal
• /
• 제15권1호
• /
• pp.42-48
• /
• 2000

본 연구에서는 고정화 UK를 이용한 융합단백질의 절단방응에 대해 UK의 고정화, 고정화 UK의 특성과 절단방응, 절단반응 후의 분리정제 그리고 고정화 UK으 재생에 대해 실험하였다. 고정화 수율은 99% 이상이였고 고정화 후의 효소활성은 80%를 유지하였다. 융합단백질 전단반응에서 액상 UK와 고정화 UK를 이용한 회분식 반응 모두 약 70%의 절단반응을 얻었고, 특히 고정화 UK의 사용시 부반응이 매우 낮은 이점이 있었다. 컬럼식 절단반응에서는 기절의 주입속도에 따라 절단수율은 크게 변화하였다. 최적의 유속은 50%의 절단수율을 얻은 1 bed volume/h로 설정하였다. 고정화 효소반응의 이점인 안정성과 반복사용 측면에서는 액상 UK 대비 고정화 UK가 높은 열안정성을 보였고 낮은 pH에서는 10% 이상 높은 활성을 유지하였다. 반복사용을 위해 6M GuHCl을 사용하여 인위적으로 풀림, 재접힘을 한 경우 98%의 활성을 얻음으로 타당성이 있음을 제시하였다. 또한 목적 단백질의 분리를 위하여 산침전 후 expanded bed adsorption 크로마토그래피를 이용함으로써 연속화된 고수율의 정제공정을 가능하게 하였다. 이러한 고정화 UK를 이용한 절단방응 및 정제시스템을 구축함으로써 융합단백지의 생산공정에 매우 유용하게 사용될 것으로 생각되어진다.

• Journal of Microbiology
• /
• 제39권3호
• /
• pp.149-153
• /
• 2001

The electron transfer reaction is one of the most essential processes of life. Not only does it provide the means of transforming solar and chemical energy into a utilizable form for all living organisms, it also extends into a range of metabolic processes that support the life of a cell. Thus, it is of great interest to understand the physical basis of the rates and reduction potentials of these reactions. To identify the major determinants of reduction potentials in redox proteins, we have chosen the simplest electron transfer protein, rubredoxin, a small (52-54 residue) iron-sulfur protein family, widely distributed in bacteria and archaea. Rubredoxins can be grouped into two classes based on the correlation of their reduction potentials with the identity of residue 44; those with Ala44 (ex: Pyrococcus furiosus) have reduction potentials that are ∼50 mV higher than those with Va144 (ex: Clostridium pasteurianum). Based on the crystal structures of rubredoxins from C. pasteurianum and P. furiosus, we propose the identity of residue 44 alone determines the reduction potential by the orientation of the electric dipole moment of the peptide bond between 43 and 44. Based on 1.5 $\AA$ resolution crystal structures and molecular dynamics simulations of oxidized and reduced rubredoxins from C. pasteurianum, the structural rearrangements upon reduction suggest specific mechanisms by which electron transfer reactions of rubredoxin should be facilitated.

• BMB Reports
• /
• 제46권3호
• /
• pp.169-174
• /
• 2013

The human $B_{12}$ trafficking chaperone hCblC is well conserved in mammals and non-mammalian eukaryotes. However, the C-terminal ~40 amino acids of hCblC vary significantly and are predicted to be deleted by alternative splicing of the encoding gene. In this study, we examined the thermostability of the bovine CblC truncated at the C-terminal variable region (t-bCblC) and its regulation by glutathione. t-bCblC is highly thermolabile ($T_m={\sim}42^{\circ}C$) similar to the full-length protein (f-bCblC). However, t-bCblC is stabilized to a greater extent than f-bCblC by binding of reduced glutathione (GSH) with increased sensitivity to GSH. In addition, binding of oxidized glutathione (GSSG) destabilizes t-bCblC to a greater extent and with increased sensitivity as compared to f-bCblC. These results indicate that t-bCblC is a more sensitive form to be regulated by glutathione than the full-length form of the protein.