Effect of Plasticizer and Cross-Linking Agent on the Physical Properties of Protein Films

Lee, Myoung-Suk,Lee, Se-Hee,Ma, Yu-Hyun,Park, Sang-Kyu,Bae, Dong-Ho,Ha, Sang-Do,Song, Kyung-Bin The Korean Society of Food Science and Nutrition 2005 Preventive Nutrition and Food Science Vol.10 No.1

To improve the physical properties of protein films, various plasticizers and cross-linking agents were used in the preparation of the films. For zein film, 3% polypropylene glycol with 3% glycerol was the best plasticizer, while 2.5% glycerol was the most suitable for soy protein isolate (SPI) film in terms of tensile strength (TS), % elongation, and water vapor permeability (WVP). Formaldehyde, glutaraldehyde, glyoxal, and cinnamaldehyde as cross-linking agents of protein films were used to further improve the physical properties of the films. All aldehydes used as cross-linking agent in this study improved TS of zein and SPI films. In particular, cinnamaldehyde was the best cross-linking agent due to its safety in foods. These results suggest that appropriate use of plasticizer and cross-linking agent like cinnamaldehyde should improve the physical properties of protein films for use in food packaging.

흰쥐의 실험적 규폐결절에서 교차결합-46 KDa 단백질의 확인

김유미,김영진,이수영 大韓産業醫學會 2003 대한직업환경의학회지 Vol.15 No.2

목적: 유리규산에 의해 유발되는 흰쥐 폐의 병 발생기전과 관련이 있는 세포들의 반응을 추구하기 위하여 이 연구를 행하였다. 방법: 500㎕의 생리식염수에 50 mg의 유리규산(S:O_2, 0.15~10㎛)을 부유시켜 체중 200 g 내외의 Sprague-Dawley 희쥐들의 기도내에 주입하여 규폐증을 유발시켰다. 규폐결절을 유리규산 주입 후 4주째에 흰쥐 폐에서 적출하였고, 이 결절들은 2%SDS, 10 M urea, 40 mM DTT를 함유한 용액속에서 4일 동안 110℃로 끓였다. 불용성 세포성 피막들은 4~12% 농도 기울기로 SDS-PAGE에서 전기 영동하였고 또한 아미노산 조성을 분석하였다. 대조군 폐와 규폐결절의 균질액의 상청액과 정상 흰쥐의 혈장을 흰쥐의 규폐결절의 교차결합 단백질에 대한 토끼 항체를 사용하여 친화성 크로마토그라피를 행하였다. 대조군 폐와 규폐결절 내 N^ε-(γ-glutamyl) lysine 교차결합의 량은 각각 HPLC 분석법을 사용하여 정량분석하였다. 결과: 교차결합 단백질은 10 M urea와 40 mM sulfhydrgl 시약내에서 오랫동안 끓여도 불용성으로 남아있었다. 피막은 단백질 내 유리규산 입자의 잔여물로서 alanine, leucine 및 glycine의 함량이 높았다. 46 KDa 단백질은 규폐결절 내 교차결합 단백질임을 친화성 크로마토그라피 방법으로 증명하였다. 규폐결절 내 N^ε-(γ-glutamyl) lysine dipeptide의 양은 대조군 폐의 량에 비하여 현저하게 증가되었다. 결론: Transglutaminase에 의하여 촉매화된 교차결합은 규폐결절 형성에 관여하며, 46 KDa 단백질은 섬유화와 섬유화로 인한 규폐결절 형성 동안 다른 세포 밖의 마트릭스 단백질 및 그 자체 단백질 내의 교차결합물인 것 같다. Objectives: This study was conducted in order to understand the cellular events associated with silica-induced pathogenesis of the rat lung. Methods: Silicosis was induced by an intratracheal instillation of 50 mg of silica (S:O_2, 0.15~10㎛) suspended in 500 ㎕ of a sterile saline solution in Sprague-Dawley rats weighing 200 g. Silicotic nodules were excised from the rat lungs 4 weeks after silica instillation, then boiled for 4 days at 110℃ in solution containing 2% SDS, 10 M urea and 40 mM DTT. The insoluble cellular encapsulates were electrophoresed on 4~12% gradient SDS-PAGE, and the amino acid composition was analyzed. Affinity chromatographies of the homogenate supernatants of the control lung, silicotic nodule, and normal rat plasma were performed using rabbit anti-rat cross-linked protein from the silicotic nodule IgG. The amounts of N^ε-(γ-glutamyl) lysine cross-link in the control lungs and silicotic nodules were determined using HPLC analysis. Results: The remaining cross-linked protein was insoluble in the 10 M urea and 40 mM sulfhydryl reagents even under prolonged boiling conditions. The encapsulate revealed the retention of silica particles within the protein whose amino acid composition showed a high percentage of alanine, leucine and glycine. A 46KDa protein was identified as a cross-linked protein in the silicotic nodule by affinity chromatography. The level of N^ε-(γ-glutamyl) lysine dipeptide in the nodule digest was prominently increased compared with that in the control lung. Conclusions: Transglutaminase(TGase)-catalyzed cross-linking appears to be involved in the silicotic nodule formation, and the 46KDa protein may be cross-linked to itself and other extracellular matrix proteins during fibrosis and the formation of eventually insoluble nodule.

Preparation of Blood Glue from Porcine Plasma Protein and Cross-linking Reaction of Plasma Protein with Formaldehyde

Cho, Yongsik,Lee, Hwahyoung,Song, Kyung Bin 한국응용생명화학회 1999 Journal of Applied Biological Chemistry (J. Appl. Vol.42 No.2

Blood glue was prepared to reutilize porcine blood. Plasma proteins after lyophilization were treated by addition of wood flour, sodium hydroxide, sodium silicate, and hydrated lime to make blood glue with a suitable adhesivity. Characteristics of the prepared blood glue was monitored by measuring the viscosity with time, and the relationship between degree of hydrolysis of plasma proteins by addition of various amounts of sodium hydroxide and adhesivity was studied. To prevent the emission of formaldehyde during manufacturing of plywood by blood glue, the cross-linking reaction of plasma protein with formaldehyde was also examined. Fourier transform infrared, circular dichroism, and fluorescence spectroscopy study showed that blood plasma proteins react with formaldehyde, resulting in removal of formaldehyde by cross-linking reaction.

Effect of a Bacterial Laccase on the Quality and Micro-Structure of Whole Wheat Bread

Wang Jingjing,Bai Han,Zhang Ran,Ding Guoao,Cai Xuran,Wang Wei,Zhu Guilan,Zhou Peng,Zhang Yan 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.12

The gluten protein content in whole-wheat flour is low, which affects the elasticity and viscosity of the dough. Enzymatic modification of the protein may result in a network that mimics gluten, which plays an important role in the processing of whole-wheat foods. In this study, the effects of Halomonas alkaliantartica laccase (LacHa) on the quality parameters of whole-wheat bread were investigated. The optimum dosage of LacHa was 4 U/100 g of whole-wheat flour. At this dosage, whole-wheat bread exhibited the best specific volume and optimum texture parameters. Laccase also extended the storage duration of whole-wheat bread. We analyzed the micro-structure of the dough to determine its gluten-free protein extractable rate and free sulfhydryl group content, and verify that LacHa mediates cross-linking of gluten-free proteins. The results demonstrated that the cross-linking of gluten-free protein by LacHa improves the texture of whole-wheat bread. As a flour improver, LacHa has great developmental and application potential in baked-food production.

Improvement of resistant starch content and baking quality of cross-linked soft rice flour

이채은,노준희,이경애,신말식 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.12

To increase resistant starch (RS) content of riceflour, soft and normal rice flours were cross-linked withdifferent flour concentrations (40, 50%). RS contents,morphology, and baking qualities of cross-linked Singilrice flour (CSRF) and Hopyeong rice flour (CHRF) werecompared. Amylose and protein contents of Singil flourwere higher than those of Hopyeong flour. The proteincontent of CSRF maintained but that of CHRF reduced. Although the RS content increased after cross-linking, thedegree of RS was higher 50% flour than 40% flour. Theshape of cross-linked rice flour particles changed intostarch granules with debris. The overall quality and textureof CSRF40 cupcake showed the highest scores by preferencetest. These results suggest that CSRF can be used as ahigh RS rice flour substitute for wheat flour, because softrice is easy to make flour.

The Schizosaccharomyces pombe Proteins that Bind to the Human HnRNPA1 Winner RNA

Kim, Jeong-Kook The Microbiological Society of Korea 1997 The journal of microbiology Vol.35 No.4

Although extensively characterized in human cells, no heterogeneous nuclear ribonucleoprotein(hnRNP) has been found in the fission yeast Schizosaccharomyces pombe which is amenable to genetic studies and more similar to mammals than Saccharomyces cerevisiae is in terms of RNA processing. As a first step to characterize hnRNPs from S. pombe, attempt was made to find human hnRNP A1 homologs from S. pombe. The RNA molecule (A1 winner) containing the consensus high-affinity hnRNP A1 binding site (UAGGGA/U) was synthesized in vitro and used in an ultraviolet(UV) light-induced protein-RNA cross-linking assay. A number of S, pombe proteins bound to the A1 winner RNA. An approximately 50-kDa protein(p50) cross-linked more efficiently to the A1 winner RNA than other proteins. The p50 protein did not cross-link to a nonspecific RNA, but rather to the A1-5’ SS RNA in which the consensus 5’ splice junction sites of S. pombe introns were abolished. This suggests that the p50 protein, however, did not bind to the single-stranded DNA to shich the human hnRNP A1 could bind and be eluted with 0.5M NaCl. Further analysis should reveal more features of this RNA-binding protein.

Synthesis of cross-linked protein-metal hybrid nanoflowers and its application in repeated batch decolorization of synthetic dyes

Patel, Sanjay K.S.,Otari, Sachin V.,Li, Jinglin,Kim, Dong Rip,Kim, Sun Chang,Cho, Byung-Kwan,Kalia, Vipin C.,Kang, Yun Chan,Lee, Jung-Kul Elsevier 2018 Journal of hazardous materials Vol.347 No.-

<P><B>Abstract</B></P> <P>Herein, we report the preparation of a cross-linked protein-metal hybrid nanoflower (NF) system for laccase immobilization. The immobilized laccase showed effective encapsulation yield and activity recovery of 78.1% and 204%, respectively. The catalytic efficiency (<I>k</I> <SUB>cat</SUB> <I>V</I> <SUB>max</SUB> <SUP>−1</SUP>) of cross-linked NF (CL-NF) was 2.2-fold more than that of free laccase. The CL-NF also exhibited significantly higher stability towards pH and temperature changes. It exhibited excellent storage stability and tolerance towards solvents and inhibitors as compared with the free enzyme. After 10 cycles of reuses, the NF and CL-NF laccase showed 41.2% and 92.3% residual activity, respectively. The CL-NF showed high oxidation potential, 265% that of the free enzyme, towards phenolic compounds. The CL-NF laccase retained the residual decolorization efficiency of up to 84.6% for synthetic dyes under repeated batch conditions of 10 cycles. These results suggested that the preparation of CL-NF is an effective approach to enhance the enzymatic properties and has great potential in many industrial applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cross-linked (CL) laccase-metal hybrid nanoflower (NF) was prepared. </LI> <LI> The catalytic efficiency of CL-NF laccase was 2.2-fold higher than that of free laccase. </LI> <LI> CL-NF laccase showed 2.6-fold higher oxidation potential than free laccase towards phenolic compounds. </LI> <LI> Under repeated batch conditions, it retained high decolorization efficiency for synthetic dyes. </LI> </UL> </P>

Photo-induced Cross-linking of Unmodified Proteins for Bioink Development and 3D Bioprinting Application

Y.-J. Choi(최영진) Korean Society for Precision Engineering 2024 한국정밀공학회 학술발표대회 논문집 Vol.2024 No.5

Structural and Functional Analysis of a β₂-Adrenergic Receptor Complex with GRK5

Komolov, Konstantin E.,Du, Yang,Duc, Nguyen Minh,Betz, Robin M.,Rodrigues, Joã,o P.G.L.M.,Leib, Ryan D.,Patra, Dhabaleswar,Skiniotis, Georgios,Adams, Christopher M.,Dror, Ron O.,Chung, Ka Young Cell Press 2017 Cell Vol. No.

<P><B>Summary</B></P> <P>The phosphorylation of agonist-occupied G-protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) functions to turn off G-protein signaling and turn on arrestin-mediated signaling. While a structural understanding of GPCR/G-protein and GPCR/arrestin complexes has emerged in recent years, the molecular architecture of a GPCR/GRK complex remains poorly defined. We used a comprehensive integrated approach of cross-linking, hydrogen-deuterium exchange mass spectrometry (MS), electron microscopy, mutagenesis, molecular dynamics simulations, and computational docking to analyze GRK5 interaction with the β<SUB>2</SUB>-adrenergic receptor (β<SUB>2</SUB>AR). These studies revealed a dynamic mechanism of complex formation that involves large conformational changes in the GRK5 RH/catalytic domain interface upon receptor binding. These changes facilitate contacts between intracellular loops 2 and 3 and the C terminus of the β<SUB>2</SUB>AR with the GRK5 RH bundle subdomain, membrane-binding surface, and kinase catalytic cleft, respectively. These studies significantly contribute to our understanding of the mechanism by which GRKs regulate the function of activated GPCRs.</P> <P><B>PaperClip</B></P> <P>Display Omitted</P> <P><B>Highlights</B></P> <P> <UL> <LI> GRK5-β<SUB>2</SUB>AR binding is enhanced by receptor and kinase ligands and acidic lipids </LI> <LI> GRK5 binding to the β<SUB>2</SUB>AR involves a multi-site interaction </LI> <LI> Receptor binding triggers substantial conformational changes in GRK5 </LI> <LI> RH/catalytic domain separation in GRK5 is essential for receptor phosphorylation </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preparation of Blood Glue from Porcine Plasma Protein and Cross-linking Reaction of Plasma Protein with Formaldehyde

( Yong Sik Cho ),( Hwa Hyoung Lee ),( Kyung Bin Song ) 한국응용생명화학회 1999 Journal of Applied Biological Chemistry (J. Appl. Vol.42 No.2