• Molecules and Cells
• /
• 제38권7호
• /
• pp.657-662
• /
• 2015

Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for removal of the large number of apoptotic cells generated in multicellular organisms. To achieve this, phagocytes need to be able to continuously uptake apoptotic cells. It was recently reported that uncoupling protein 2 (Ucp2) promotes engulfment of apoptotic cells by increasing the phagocytic capacity, thereby allowing cells to continuously ingest apoptotic cells. However, the functions of Ucp2, beyond its possible role in dissipating the mitochondrial membrane potential, that contribute to elevation of the phagocytic capacity have not been determined. Here, we report that the anion transfer or nucleotide binding activity of Ucp2, as well as its dissipation of the mitochondrial membrane potential, is necessary for Ucp2-mediated engulfment of apoptotic cells. To study these properties, we generated Ucp2 mutations that affected three different functions of Ucp2, namely, dissipation of the mitochondrial membrane potential, transfer of anions, and binding of purine nucleotides. Mutations of Ucp2 that affected the proton leak did not enhance the engulfment of apoptotic cells. Although anion transfer and nucleotide binding mutations did not affect the mitochondrial membrane potential, they exerted a dominant-negative effect on Ucp2-mediated engulfment. Furthermore, none of our Ucp2 mutations increased the phagocytic capacity. We conclude that dissipation of the proton gradient by Ucp2 is not the only determinant of the phagocytic capacity and that anion transfer or nucleotide binding by Ucp2 is also essential for Ucp2-mediated engulfment of apoptotic cells.

• Journal of Microbiology and Biotechnology
• /
• 제25권7호
• /
• pp.963-977
• /
• 2015

The well-characterized gram-positive bacterium Bacillus subtilis is an outstanding industrial candidate for protein expression owing to its single membrane and high capacity of secretion, simplifying the downstream processing of secretory proteins. During the last few years, there has been continuous progress in the illustration of secretion mechanisms and application of this robust host in various fields of life science, such as enzyme production, feed additives, and food and pharmaceutical industries. Here, we review the developments of Bacillus subtilis as a highly promising expression system illuminating strong chemical- and temperatureinducible and other types of promoters, strategies for ribosome-binding-site utilization, and the novel approach of signal peptide selection. Furthermore, we outline the main steps of the Sec pathway and the relevant elements as well as their interactions. In addition, we introduce the latest discoveries of Tat-related complex structures and functions and the countless applications of this full-folded protein secretion pathway. This review also lists some of the current understandings of ATP-binding cassette transporters. According to the extensive knowledge on the genetic modification strategies and molecular biology of Bacillus subtilis, we propose some suggestions and strategies for improving the yield of intended productions. We expect this to promote striking future developments in the optimization and application of this bacterium.

• 한국자기공명학회논문지
• /
• 제10권2호
• /
• pp.155-162
• /
• 2006

Angiogenin is unique among angiogenic molecules in that it is a member of the pancreatic ribonuclease superfamily and, in fact, is a ribonucleolytic enzyme. Its enzymatic activity is extremely weak compared to that of the digestive RNases but is critical for its capacity to induce neovascularization. In this study, we completed the backbone resonance assignment of bovine angiogenin using triple resonance NMR experiments of $^{15}N\;and/or\;^{13}C$ isotope labeled protein and investigated the chemical shift variation upon binding with inhibitor phosphate ion and determine the phosphate binding site.

• 한국식품영양과학회지
• /
• 제29권2호
• /
• pp.280-287
• /
• 2000

Generally, buckwheat has been regarded as a crop of secondary importance in many countries. In vitro functionalities of buckwheats as a food were evaluated in this study. Five of buckwheat cultivars were extracted with methanol, and the extractant were dried and lyophilized, separately. Or water soluble buckwheat components were digested with the commercial enzymes and the obtained protein hydrolysate was again fractionated by acid precipitation. The antioxidant capacity of the methanol extracts determined using Fe2+-ascorbic acid system was dependent ont the cultivars: The extract of Suwon 4 showed 3.3 times stronger activity than ascorbic acid in terms of IC50. Also, the extracts of buckwheats inhibited efficiently the activities of $\alpha$-amylase and lens aldose reductase. Buckwheat soluble protein or rutin suppressed the in vitro activities of angiotensin-converting enzyme, and the inhibitory degree depended largely on the cultivars. Buckwheat proteins exerted higher hydrophobicity being related to the sterol binding capacity than casein. The results suggested that buckwheat seeds may be desirable and functional food resources in human living in current society.

• 한국미생물·생명공학회지
• /
• 제47권2호
• /
• pp.278-288
• /
• 2019

In the present investigation, we attempted to design a protocol to develop a hybrid protein with better bioremediation capacity. Using in silico approaches, a Hybrid Open Reading Frame (Hybrid ORF) is developed targeting the genes of microorganisms known for degradation of organophosphates. Out of 21 genes identified through BLAST search, 8 structurally similar genes (opdA, opd, opaA, pte RO, pdeA, parC, mpd and phnE) involved in biodegradation were screened. Gene conservational analysis categorizes these organophosphates degrading 8 genes into 4 super families i.e., Metallo-dependent hydrolases, Lactamase B, MPP and TM_PBP2 superfamily. Hybrid protein structure was modeled using multi-template homology modeling (3S07_A; 99%, 1P9E_A; 98%, 2ZO9_B; 33%, 2DXL_A; 33%) by $Schr{\ddot{o}}dinger$ software suit version 10.4.018. Structural verification of protein models was done using Ramachandran plot, it was showing 96.0% residue in the favored region, which was verified using RAMPAGE. The phosphotriesterase protein was showing the highest structural similarity with hybrid protein having raw score 984. The 5 binding sites of hybrid protein were identified through binding site prediction. The docking study shows that hybrid protein potentially interacts with 10 different organophosphates. The study results indicate that the hybrid protein designed has the capability of degrading a wide range of organophosphate compounds.

• 한국식품영양과학회지
• /
• 제18권2호
• /
• pp.195-198
• /
• 1989

도축장에서는 폐기되는 돼지 혈액으로부터 혈장을 분리하여, pH, 온도, 단백질함량에 따른 혈장 단백질 보수력의 변화를 조사하였다. 돼지 혈액으로부터 혈장분리는 1400g-force에서 가장 좋았다. 단백질 농도가 5%인 혈장액을 $85^{\circ}C$에서 30분간 가열하였을 때 pH가 증가함에 따라 혈장단백질보수력은 급격히 증가하다가 pH 7 이후에는 완만한 증가를 나타냈다. 단백질 농도가 5%이고 pH 7인 혈장액에서의 보수력은 gel화 온도가 높을수록 짧은 시간 내에 높은 보수력을 나타냈으며 가열 초기에 급격히 증가하다가 일정 가열 시간 이후에는 큰 변화를 나타내지 않았다. pH가 7인 혈장액을 $85^{\circ}C$에서 30분간 가열하였을 때 혈장 단백질의 농도가 증가함에 따라 단위 단백질 무게당 보수력은 감소하였다.

• 한국식품과학회지
• /
• 제4권2호
• /
• pp.90-94
• /
• 1972

대맥주요(大麥主要)품종 22개의 보리쌀 중 단백질(蛋白質) 및 전탄수화물(全炭水化物) 함량(含量)을 분석(分析)하고 재배현황(栽培現況)의 연간추이(年間趨移)와 관계(關聯) 검토(檢討)하였다. 조단백함량(粗蛋白含量) $(N{\times}5.83)$은 평균(平均) 8.60 최고(最高) 15.39% 최소(最小) 6.06%이었고 약 1/3이 평균치(平均値) 이상(以上)이었다. 조단백(粗蛋白) 함량(含量)은 dye-binding capacity와 유의정상관(有意正相關)$(r=0.82^{**})$을 보였으나 탄수화물(炭水化物)과는 유의성(有意性)없는 부상관(否相關)을 보였다. 경1호(京1號)(15.39%), 관취기(關取埼)(12.42%) 및 영월육각(寧越六角)(11.95%)의 세품종만 고단백품종(高蛋白品種)으로 볼 수 있으나 거의 재배(栽培)되지 않고 있다. 지난 10년간(年間) 대맥(大麥)의 품종별 재배면적비(品種別 栽培面積比)는 거의 변화(變化)가 없으며 조단백함량(粗蛋白含量) 평균치이상(平均値以上)이 품종(品種)이 전대맥재배면적(全大麥栽培面積)의 약 50%를 차지하고 있으며 경남대맥(慶南大麥) 89호(號)는 단백함량(蛋白含量)이 상당히 낮은 데도 불구(不拘)하고 8%의 면적(面積)을 차지하고 있다.

• BMB Reports
• /
• 제31권4호
• /
• pp.370-376
• /
• 1998

Src-Homology 2 (SH2) domains have a capacity to bind phosphotyrosine-containing sequence context and play essential roles in various cellular signaling pathways. Due to the specific nature of the binding between SH2 domains and their counterpart proteins, inhibitors of SID domain binding have drawn extensive attention as a potential candidate for therapeutic agents. Here, we describe the binding assay system to screen for the ligands or blockers of the SH2 domains with an emphasis on the $p56^{lck}$ SH2 domain. In our assay system, SID domains expressed and purified as fusion proteins to Glutathione-S-transferase (GST) were covalently attached to 96-well microtitre plates through amide bond formation, which were subsequently allowed to bind the biotinylated phosphotyrosine (pY)containing synthetic pep tides. The binding of biotinylated pY peptides was detected by the horseradish peroxidase (HRP)-conjugated streptavidin. Using the various combinations of SH2 domain-pY peptides, we observed that: (1) The binding of pY-peptides to its counterpart SH2 domain is concentration-dependent and saturable; (2) The binding is highly specific for a particular combination of SH2 domain-pY peptide pair; and (3) The binding of Lck SH2-cognate pY-peptides is specifically competed by the nonbiotinylated peptides with expected relative affinity. These results indicate that the established assay system detects the SH2-pY peptide interaction with reproducible sensitivity and specificity and is suitable for screening the specific inhibitors of $p56^{lck}$ SH2 function.

• 한국어병학회지
• /
• 제27권2호
• /
• pp.99-105
• /
• 2014

Biosensors consist of biochemical recognition agents like antibodies immobilized on the surfaces of transducers that change the recognition into a measurable electronic signal. Here we report a piezoelectric immunosensor made to detect Vibrio vulnificus. A 9MHz AT-cut piezoelectric wafer attached with two gold electrodes of 5mm diameter was used as the transducer of the QCM biosensor with a reproducibility of ${\pm}0.1Hz$ in frequency response. We have tried different approaches to immobilize antibody on the sensor chip. Concerning the orientation of antibody for the best antigen binding capacity, the antibody was immobilized by specific binding to protein G or by cross-linking through hydrazine. In addition, protein G was cross-linked on glutaraldehyde activated immine layer (PEI) or EDC/NHS activated sulfide monolayer (MPA). PEI was found to be more effective to immobilize protein G following glutaraldehyde activation than MPA. However, hydrazine chip showed a better capability to immobilize more IgG than protein G chip and a higher sensitivity. The sensor system was able to detect V. vulnificus in dose dependent manner and was able to detect bacterial cells within 5 minutes by monitoring frequency shifts in real time. The detection limit can be improved by preincubation to enrich the bacterial cell number.

• BMB Reports
• /
• 제42권3호
• /
• pp.160-165
• /
• 2009

The temperate Staphylococcus aureus phage ${\Phi}11$ harbors cI and cro repressor genes similar to those of lambdoid phages. Using extremely pure ${\Phi}11$ Cro (the product of the ${\Phi}11$ cro gene) we demonstrated that this protein possesses a single domain structure, forms dimers in solution at micromolar concentrations and maintains a largely $\alpha$-helical structure even at $45^{\circ}C$. ${\Phi}11$ Cro was sensitive to thermolysin at temperatures ranging from $55-75^{\circ}C$ and began to aggregate at ${\sim}63^{\circ}C$, suggesting that the protein is moderately thermostable. Of the three homologous 15-bp operators (O1, O2, and O3) in the ${\Phi}11$ cI-cro intergenic region, ${\Phi}11$ Cro only binds efficiently to O3, which is located upstream of the cI gene. Our comparative analyses indicate that the DNA binding capacity, secondary structure and dimerization efficiency of thermostable ${\Phi}11$ Cro are distinct from those of P22 Cro and $\lambda$ Cro, the best characterized representatives of the two structurally different Cro families.