• Title/Summary/Keyword: polypeptides

Search Result 232, Processing Time 0.021 seconds

Screening Peptides Binding Specifically to Colorectal Cancer Cells from a Phage Random Peptide Library

  • Wang, Jun-Jiang;Liu, Ying;Zheng, Yang;Liao, Kang-Xiong;Lin, Feng;Wu, Cheng-Tang;Cai, Guan-Fu;Yao, Xue-Qing
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.1
    • /
    • pp.377-381
    • /
    • 2012
  • The aim of this study was to screen for polypeptides binding specifically to LoVo human colorectal cancer cells using a phage-displayed peptide library as a targeting vector for colorectal cancer therapy. Human normal colorectal mucous epithelial cells were applied as absorber cells for subtraction biopanning with a c7c phage display peptide library. Positive phage clones were identified by enzyme-linked immunosorbent assay and immunofluorescence detection; amino acid sequences were deduced by DNA sequencing. After 3 rounds of screening, 5 of 20 phage clones screened positive, showing specific binding to LoVo cells and a conserved RPM motif. Specific peptides against colorectal cancer cells could be obtained from a phage display peptide library and may be used as potential vectors for targeting therapy for colorectal cancer.

Changes in the Expression of ADP-Glucose Pyrophosphorylase Genes During Fruit Ripening in Strawberry

  • Park, Jeong-Il;Kim, In-Jung
    • Food Science and Biotechnology
    • /
    • v.16 no.3
    • /
    • pp.343-348
    • /
    • 2007
  • Starch contents play important roles in determining the fruit quality. Stawberry accumulates starch in the early stages and then mobilized into soluble sugars during fruit ripening. To date the molecular studies on the ADP-glucose pyrophosphorylase (AGPase), a key enzyme of starch biosynthesis, were not reported. cDNAs encoding small (FagpS) and large (FagpL1 and FaspL2) AGPase subunits were isolated from strawberry (Fragaria ${\times}$ ananassa Duch. cv. Niyobou). Both FagpS and FagpL1 cDNAs have open reading frames deriving 55-58 kDa polypeptides, where FagpL2 contains a partial fragment. Sequence analyses showed that FagpS has a glutamate-threonine-cysteine-leucine (ETCL) instead of a glutamine-threonine-cysteine-leucine (QTCL) motif found in all the dicot plants except for Citrus. In fruits, FagpS and FagpL1 were expressed in all stages with a little change in the amounts of transcripts. In the case of FagpL2, we were not able to detect any signal from all stages of fruit development and all tissues except for very a weak signal from the leaf. The results indicate that FagpL1 and FagpL2 show ubiquitous and leaf-specific expression patterns, respectively. The studies suggest that the starch contents in strawberry might be controlled by the expression of AGPase gene at both the transcriptional and post-transcriptional levels during fruit development.

Parenteral Formulations Based on Albumin Particulate Technology

  • Lee, Hong-Hwa;Lee, Min-Jung;Heo, Sun-Ju;Sah, Hong-Kee
    • Journal of Pharmaceutical Investigation
    • /
    • v.40 no.spc
    • /
    • pp.83-95
    • /
    • 2010
  • Over the years, nanoparticle drug delivery systems have demonstrated versatile potentials in biological, medical and pharmaceutical applications. In the pharmaceutical industry nanotechnology research has mainly focused on providing controlled drug release, targeting their delivery to specific organs, and developing parenteral formulations for poorly water soluble drugs to improve their bioavailability. Achievement in polymer industry has generated numerous polymers applicable to designing nanoparticles. From viewpoints of product development, a nanocarrier material should meet requirements for biodegradability, biocompatibility, availability, and regulatory approval crieteria. Albumin is indeed a material that fulfills such requirements. Also, the commercialization of a first albumin-bound paclitaxel nanoparticle product (Abraxane$^{TM}$) has sparked renewed interests in the application of albumin in the development of nanoparticle formulations. This paper reviews the intrinsic properties of albumin, its suitability as a nanocarrier material, and albumin-based parenteral formulation approaches. Particularly discussed in detail are albumin-based particulate injectables such as Abraxane$^{TM}$. Information on key roles of albumin in the nab$^{TM}$ technology and representative manufacturing processes of albumin particulate products are provided. It is likely that albumin-based particulate technology would extend its applications in delivering drugs, polypeptides, proteins, vaccines, nucleic acids, and genes.

The Properties of Acetolactate Synthase Isozyme Produced by Serratia marcescens ATCC 254 19 (Serratia marcescens ATCC 25419가 생산하는 Acetolactate Synthase Isozyme의 특성)

  • 김종탁;김승수
    • Microbiology and Biotechnology Letters
    • /
    • v.20 no.1
    • /
    • pp.25-33
    • /
    • 1992
  • One acetolactate synthase isozyme which has Rf value of 0.83 on polyacrylamide gel electrophoresis was purified from Sewatia marcescens ATCC 25419 by ammonium sulfate fractionation, DEAE-Sephacel chromatography, Phenyl-Sepharose chromatography, Sephacryt S-400 gel filtration followed by native gel elution. The native molecular weight of the enzyme was determined to be 531,400 by gel filtration method, and SDS-polyacrylamide gel electrophoresis separated the native enzyme into two polypeptides having molecular sizes of 55,000 and 38,900 respectively. In kinetic parameters, $K_m$ value for pyruvate was 2.54 mM, and $V_{max}$ was 21.75 nmoie/min/mg. The enzyme showed maximal activity around pH 8.0 and optimal temperature of the acetolactate formation was $37^{\circ}C$. Feedback inhibition studies indicate that the purified enzyme is rather resistant to branched chain amino acids when compared with acetolactate synthase isozymes of plants or other enterobacteria.

  • PDF

Sll0396 regulates transcription of the phycocyanin genes in Synechocystis sp. PCC 6803

  • Oh, In-Hye;Kim, Ho-San;Chung, Young-Ho;Kim, Young-Hye;Park, Young-Mok
    • Plant Biotechnology Reports
    • /
    • v.4 no.3
    • /
    • pp.193-199
    • /
    • 2010
  • An olive-green mutant was generated in Synechocystis sp. strain PCC 6803 by inactivation of the sll0396 gene. Whole-cell absorption spectra of the mutant revealed the missing of phycocyanin peak. An investigation of the low-temperature fluorescence emission spectra revealed that the $sll0396{\Omega}$ mutant has a reduced amount of phycocyanin. Western blot analysis showed that the mutant contained less phycocyanin ${\beta}$- and ${\alpha}$-subunits and lacked the 30- and 32-kDa linker polypeptides, and northern blot analysis revealed that the transcription of the 1.4-kb cpcBA gene encoding the phycocyanin ${\beta}$- and ${\alpha}$-subunits was lower in the mutant. The Sll0396 protein has a DNA-binding motif and shares homology with known response regulators. Our results indicate that Sll0396 plays a regulatory role in the transcription of the phycocyanin genes during phycobilisome synthesis.

Isolation and Characterization of an Extremely Thermophilic Sulfur-metabolizing Bacterium from a Deep-sea Hydrothermal Vent System

  • Kwak, Yi-Seong;Kobayashi, Tetsuo;Akiba, Teruhiko;Horikoshi, Koki;Kim, Young-Bae
    • Journal of Microbiology and Biotechnology
    • /
    • v.4 no.1
    • /
    • pp.36-40
    • /
    • 1994
  • A water sample was taken from a black smoker chimney of a deep-sea hydrothermal vent by using an unmanned submersible "Dolphin 3K". The temperature of the hydrothermal fluid from the black smoker was $276^{\circ}C$. After isolation by repeated serial dilutions, An extremely thermophilic bacterial strain was selected. The strain designated as DT1331, was an anaerobic, non-motile, coccoid shaped bacterium with about 0.5 to $1.0\;\mu\textrm{m}$ in diameter. The strain DT1331 could grow up to $93^{\circ}C$, but the optimum temperature of this strain was $80^{\circ}C$. The growth occurred in the pH range of 4.5 to 8.5 and the optimum pH was 6.0. The strain DT1331 required 1% to 5% NaCl for growth and cell lysis was observed below 1% NaCl concentration. The bacterium could grow on polypeptides such as tryptone, peptone, soytone and on proteins such as casein or gelatin. However, no growth was observed on single amino acids, sugar and organic acids. Hydrogen gas was detected slightly during growth. This bacterium obligately required elemental sulfur and hydrogen sulfide gas was produced during growth.

  • PDF

Molecular Cloning and Sequencing of the Bacillus subtilis cdd Gene Encoding Dooxycytindine-Cytidine Deaminase

  • Song, Bang-Ho;Neuhard, Jan
    • Proceedings of the Korean Society for Applied Microbiology Conference
    • /
    • 1986.12a
    • /
    • pp.512.1-512
    • /
    • 1986
  • The cdd gene of Bacillus subtilis, encoding the deoxycytidinecytidine deaminase of pyrimidine nucleotide biosynthesis has been cloned into the EcoRl site of pBR322. The recombinant plasmid, pSol, promoted the synthesis of 100-140 fold elevated levels of the enzyme. A comparison of the polypeptides encoded by cdd complementing and non-complementing plasmids in the mini cell showed the gene product to have a molecular mass of approximately 14 kDa. The nucleotide sequence of the gene and 460 base pairs upstream from the coding region was determined. An open-reading frame, encoding a protein with a calculated molecular mass of 14337 Da, was deduced to be the coding region for cdd. However, the enzyme has an apparent molecular mass of 54 kDa as determined by gel filteration, whereas sucrose density gradient centrifugation shows 58 kDa. It means that the enzyme could be forming a tetramer in a physiological state. About 28 amino acids of the N-tetramer in a physiological state. About 28 amino acids of the N-terminal presumably form a signal for membrane translocation and six cystein residues are contained in the structure. S1 nuclease mapping indicated that transcription of cdd is initiated 17 base pairs upstream from the translational start. The structural characterization of the odd gene was performed.

  • PDF

Electron Microscopy Studies on the Formation of Polyhedra Occlusion Bodies of Autographa californica Nuclear Polyhedrosis Virus (미생물 살충제인 Autographa californica Nuclear Polyhydrosis Virus의 Polyhydra 형성 과정의 전자현미경적 연구)

  • Lee Hyung-Hoan
    • Applied Microscopy
    • /
    • v.11 no.1
    • /
    • pp.51-57
    • /
    • 1981
  • The process of the formation of polyhedra occlusion bodies and occlusion of viral nucleocapsids of Autographa californica Nuclear Polyhedrosis Virus in Spodoptera frugiperda cell were photomicrographed and described. Progeny viral nucleocapsids were observed in the nuclei of the host cells, bundled and then enveloped. The nucleoapsids were mainly accumulated near the membrane-like profiles. The nuclear membrane were hypertophied up to the cytoplasmic membrane. Prepolyhedral bodies were observed and they were growing with the accumulations of thread-like materials(polypeptides) produced by viral genes. The bundled and enveloped nucleocapsids were occluded into the growing polyhedra.

  • PDF

Characterization of the Plasmid-Encoded Arsenic Salts Resistance Determinant from Klebsiella oxytoca D12

  • Rhie, Ho-Gun;Lee, Sung-Jae;Lee, Ho-Sa
    • Journal of Microbiology and Biotechnology
    • /
    • v.14 no.3
    • /
    • pp.593-598
    • /
    • 2004
  • The arsenical resistance (ars) operon was cloned from a 67-kilobase pair (kb) plasmid, which was previously shown to be responsible for arsenic salts resistance in K. oxytoca D12. When plasmid pAE48, carrying the ars operon, was transformed into E. coli, transformed cells displayed enhanced survival in the presence of 4 mM arsenite, 50 mM arsenate, or 0.4 mM antimonite. The nucleotide sequence of the 5.6-kb fragment encoding arsenical resistance revealed five open reading frames (ORFs), which were predicted to encode polypeptides of 12.8 (arsR), 13.4 (arsD), 62.6 (arsA), 45 (arsB), and 16.7 (arse) kilodaltons (kDa). Each ORF was preceded by a ribosome binding site. A putative promoter-like sequence was identified upstream of arsR, and a possible termination site was found downstream of arsC. When the deduced amino acid sequences of the K. oxytoca Dl2 Ars proteins were compared with the amino acid sequences of the E. coli R773 Ars proteins, a significant amino acid similarity was observed (87.9% for ArsR, 89.2% for ArsD, 83.2% for ArsA, 92.6% for ArsB, and 91.3% for ArsC), suggesting an evolutionary relationship of the ars genes of E. coli plasmid R773 and K. oxytoca Dl2.

Molecular Association of Glucose Transporter in the Plasma Membrane of Rat Adipocyte

  • Hah, Jong-Sik
    • The Korean Journal of Physiology
    • /
    • v.25 no.2
    • /
    • pp.115-123
    • /
    • 1991
  • Molecular association of glucose transporters with the other proteins in the plasma membrane was assessed by gel electrophoresis and immunoblot techniques. Approximately $31.5{\pm}5.1%$ of GLUT-4, $64.8{\pm}2.7%$ of clathrin, 48.7% of total protein in the plasma membrane (PM) were found insoluble upon extraction with 1% Tx-100. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that the Tx-100 insoluble PM fraction contained about 4 major polypeptides with apparent molecular weight of above 200, 100-120, 80 and 30-35 KDa that were readily removed upon wash with a high pH buffer which is known to remove clathrin and 0.5 M Tris-buffer which is known to remove assembly proteins (AP). Immunoblotting of GLUT4 and clathrin against specific antibodies showed that GLUT-4 and clathrin were co-solubilized up to 84.6% and 82.7% respectively by wash with a high pH buffer and 1% Tx-100. When the membrane was pre-washed with a high pH buffer and 0.5 M Tris solution, GLUT4 and clathrin were not solubilized further suggesting that GLUT4 molecules are in molecular association with clathrin, AP and/or other extrinsic membrane proteins in plasma membrane and the formation of clathrin-coated structures might be involved in insulin stimulated glucose transporter translocation mechanism.

  • PDF