• Title/Summary/Keyword: Protein A

Search Result 29,963, Processing Time 0.055 seconds

Facile radiolabeling of antibody-mimetic protein with In-111 via an inverse-electron-demand Diels-Alder reaction

  • Nam, You Ree;Shim, Ha Eun;Lee, Dong-Eun
    • Journal of Radiopharmaceuticals and Molecular Probes
    • /
    • v.5 no.2
    • /
    • pp.83-88
    • /
    • 2019
  • In order to understand the in vivo biodistribution of repebody protein (RB), an efficient and simple radiolabeling method for the protein is needed. We demonstrate a detailed protocol for the radiosynthesis of an 111In radiolabeled tetrazine prosthetic group and its application to the efficient radiolabeling of trans-cyclooctene-group conjugated repebody protein using inverse-electron-demand Diels-Alder reaction. First, 1,2,4,5-tetrazine (Tz) conjugated with a DOTA chelator, was used for preparing the radiolabeled DOTA complex with 111In. Second, the trans-cyclooctene (TCO) functionalized repebody protein was synthesized which allows for the preparation of radiolabeled proteins by copper-free click chemistry. Following incubation with the 111In-radiolabeled DOTA complex (111In-Tz), the TCO-functionalized RB (TCO-RB) was radiolabeled successfully with 111In, with a high radiochemical yield (69.5%) and radiochemical purity (>99%). The radiolabeling of repebody protein by copper-free click chemistry was accomplished within 20 min, with great efficiency in aqueous conditions. These results clearly indicate that the present radiolabeling method will be useful for the efficient and convenient radiolabeling of trans-cyclooctene-group containing biomolecules.

Molecular Cloning and Recombinant Expression of the Long Form of Leptin Receptor (Ob-Rb) cDNA as Isolated from Rat Spleen

  • Ju, Sung-Kyu;Park, Jung-Hyun;Na, Shin-Young;You, Kwan-Hee;Kim, Kil-Lyong;Lee, Myung-Kyu
    • BMB Reports
    • /
    • v.34 no.2
    • /
    • pp.156-165
    • /
    • 2001
  • Leptin is a circulating non-glycosylated protein that is mainly produced in adipocytes. Leptin acts in the brain to regulate food intake and energy expenditure. Previously we reported our success in the isolation of a partial cDNA of the long form of the leptin receptor, OB-Rb, from rat spleen, and showed that leptin might also play a role in peripheral immune organs. In the present study, for the first time, the complete coding region of OB-Rb cDNA was cloned from rat splenocytes, and its nucleotide sequence was determined. The cDNA was then further expressed in E. coli and mammalian cells, thereby confirming the functional integrity of this receptor. Prokaryotically overexpressed OB-R protein was then used as an immunizing antigen in BALE/c mice to produce leptin receptor-specific antibodies. By using them, we confirmed the cell surface expression of OB-Rb in transfected CHO cells. It is our belief that the reagents, as produced in this study, will be of great use in further studies of the biological role of rat leptin.

  • PDF

Increasing the Flow of Protein from Ruminal Fermentation - Review -

  • Wallace, R.J.;Newbold, C.J.;Bequette, B.J.;MacRae, J.C.;Lobley, G.E.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.6
    • /
    • pp.885-893
    • /
    • 2001
  • This review summarizes some recent research into ways of improving the productivity of ruminal fermentation by increasing protein flow from the rumen and decreasing the breakdown of protein that results from the action of ruminal microorganisms. Proteinases derived from the plant seem to be of importance to the overall process of proteolysis in grazing animals. Thus, altering the expression of proteinases in grasses may be a way of improving their nutritive value for ruminants. Inhibiting rumen microbial activity in ammonia formation remains an important objective: new ways of inhibiting peptide and amino acid breakdown are described. Rumen protozoa cause much of the bacterial protein turnover which occurs in the rumen. The major impact of defaunation on N recycling in the sheep rumen is described. Alternatively, if the efficiency of microbial protein synthesis can be increased by judicious addition of certain individual amino acids, protein flow from ruminal fermentation may be increased. Proline may be a key amino acid for non-cellulolytic bacteria, while phenylalanine is important for cellulolytic species. Inhibiting rumen wall tissue breakdown appears to be an important mechanism by which the antibiotic, flavomycin, improves N retention in ruminants. A role for Fusobacterium necrophorum seems likely, and alternative methods for its regulation are required, since growth-promoting antibiotics will soon be banned in many countries.

HEMATOLOGICAL RESPONSE OF SAUDI ARABIAN FOWL TO PROTEIN REARING REGIMENS

  • Alsobayel, A.A.;Attia, F.M.;Bayoumi, M.S.;Haroun, I.Y.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.3 no.2
    • /
    • pp.107-114
    • /
    • 1990
  • The purpose of this investigation was to study the hematological response of Saudi Arabian Baladi fowl to protein rearing regimens. Males and females were subjected to the following 4 protein rearing regimens: conventional, C; reverse protein, RP; 2 single-stage low protein, $SS_1$ and $SS_2$ using 15% and 12% CP diets, respectively. Regimen effect was highly significant ($$p{\leq_-}.01$$) on BW, PCY, TP and U-Ac and significant ($$p{\leq_-}.05$$) on TL. Serum chol levels were not affected by regimen. In general $SS_{2}$ birds showed the lowest values for all parameters studied, except for PCV. However, the differences were not significant in each case. Age and sex effects were highly significant ($$p{\leq_-}.01$$) for all parameters, however, the regimen X sex interaction was not significant except for PCV. Regimen X age interaction, on the other hand, was highly significant ($$p{\leq_-}.01$$) only for BW, TP and U-Ac concentrations. The data may suggest that low levels of protein in the rearing regimen is an important factor influencing levels of the blood parameters studied. The data also indicate a lack of clear relationship between hen-day egg production and the blood parameters studied.

Regulation of RIP3 protein stability by PELI1-mediated proteasome-dependent degradation

  • Park, Han-Hee;Morgan, Michael J.;Kang, Ho Chul;Kim, You-Sun
    • BMB Reports
    • /
    • v.51 no.10
    • /
    • pp.484-485
    • /
    • 2018
  • Receptor-interacting protein kinase-3 (RIP3 or RIPK3) is a serine-threonine kinase largely essential for necroptotic cell death; it also plays a role in some inflammatory diseases. High levels of RIP3 are likely sufficient to activate necroptotic and inflammatory pathways downstream of RIP3 in the absence of an upstream stimulus. For example, we have previously detected high levels or RIP3 in the skin of Toxic Epidermal Necrolysis patients; this correlates with increased phosphorylation of MLKL found in these patients. We have long surmised that there are molecular mechanisms to prevent anomalous activity of the RIP3 protein, and so prevent undesirable cell death and inflammatory effects when inappropriately activated. Recent discovery that Carboxyl terminus of Hsp 70-Interacting Protein (CHIP) could mediate ubiquitylation- and lysosome-dependent RIP3 degradation provides a potential protein that has this capacity. However, while screening for RIP3-binding proteins, we discovered that pellino E3 ubiquitin protein ligase 1 (PELI1) also interacts directly with RIP3 protein; further investigation in this study revealed that PELI1 also targets RIP3 for proteasome-dependent degradation. Interestingly, unlike CHIP, which targets RIP3 more generally, PELI1 preferentially targets kinase active RIP3 that has been phosphorylated on T182, subsequently leading to RIP3 degradation.

Metacercarial proteins interacting with WD40-repeat protein of Clonorchis sinensis

  • Cho, Pyo-Yun;Kim, Tae-Im;Li, Shunyu;Hong, Sung-Jong;Choi, Min-Ho;Hong, Sung-Tae;Chung, Yong-Je
    • Parasites, Hosts and Diseases
    • /
    • v.45 no.3
    • /
    • pp.229-232
    • /
    • 2007
  • The WD40-repeat proteins serve as a platform coordinating partner proteins and are involved in a range of regulatory cellular functions. A WD40-repeat protein (CsWD1) of Clonorchis sinensis previously cloned is expressed stage-specifically in the tegumental syncytium of C. sinensis metacercariae. In the present study, interact-ing proteins with the CsWD1 protein was purified by immunoprecipitation and 2 dimension gel electrophoresis from the C. sinensis metacercaria soluble extract, and tryptic peptides were analyzed by LC/ESI-MS. Putative partner proteins were annotated to be actin-2, glyceraldehyde-3-phosphate dehydrogenase, and hypothetical and unmanned proteins. The CsWD1 protein was predicted to contain 3 conserved actin-interacting residues on its functional surface. With these results, the CsWD1 protein is suggested to be an actin-interacting protein of C. sinensis.

Sequence Analysis of the Coat Protein Gene of a Korean Isolate of Iris Severe Mosaic Potyvirus from Iris Plant

  • Park, Won-Mok;Lee, Sang-Seon;Park, Sun-Hee;Ju;Ryu, Ki-Hyun
    • The Plant Pathology Journal
    • /
    • v.16 no.1
    • /
    • pp.36-42
    • /
    • 2000
  • The coat protein gene of iris severe mosaic potyvirus, which was isolated in Korea, ISMV-K, from iris plant was cloned and its nucleotide sequence was determined. The coat protein of the virus contained 252 amino acid residues, including five potential N-glyxosylation site motifs. The coat protein of ISMV-K has 99.1% and 98.4% sequence identities with those of the Netherlands isolate of ISMV (ISMV-Ne) form crocus for the nucleotide and amino acids, respectively. The coat protein of ISMV-K has 50.4% to 60.3% nucleotide sequence identities and 47.3% to 55.7% amino acid identities with those of other 21 potyviruses, indicating ISMV to be a distinct species of the genus. The coat protein of ISMV-K was closely related with bean yellow mosaic virus and clover yellow vein virus in the phylogenetic tree analysis among the potyviruses analyzed. ISMV was easily and reliably detected from virus-infected iris leaves by RT-PCR with a set of the virus-specific primers.

  • PDF

Prediction of Protein Kinase Specific Phosphorylation Sites with Multiple SVMs

  • Lee, Won-Chul;Kim, Dong-Sup
    • Bioinformatics and Biosystems
    • /
    • v.2 no.1
    • /
    • pp.28-32
    • /
    • 2007
  • The protein phosphorylation is one of the important processes in the cell signaling pathway. A variety of protein kinase families are involved in this process, and each kinase family phosphorylates different kinds of substrate proteins. Many methods to predict the kinase-specific phosphoryrated sites or different types of phosphorylated residues (Serine/Threonine or Tyrosin) have been developed. We employed Supprot Vector Machine (SVM) to attempt the prediction of protein kinase specific phosphorylation sites. 10 different kinds of protein kinase families (PKA, PKC, CK2, CDK, CaM-KII, PKB, MAPK, EGFR) were considered in this study. We defined 9 residues around a phosphorylated residue as a deterministic instance from which protein kinases determine whether they act on. The subsets of PSI-BALST profile was converted to the numerical vectors to represent positive or negative instances. When SVM training, We took advantage of multiple SVMs because of the unbalanced training sets. Representative negative instances were drawn multiple times, and generated new traing sets with the same positive instances in the original traing set. When testing, the final decisions were made by the votes of those multiple SVMs. Generally, RBF kernel was used for the SVMs, and several parameters such as gamma and cost factor were tested. Our approach achieved more than 90% specificity throughout the protein kinase families, while the sensitivities recorded 60% on average.

  • PDF

Over-expression of Chlamydia psittaci MOMP in Escherichia coli and its purification (대장균에서 Chlamydia psittaci MOMP 유전자의 과발현과 순수분리)

  • Ha, Jung-Soon;Lee, Do-Bu;Han, Sang-Hoon;Lim, Yoon-Kyu;Yoon, Byoung-Su
    • Korean Journal of Veterinary Research
    • /
    • v.46 no.1
    • /
    • pp.13-19
    • /
    • 2006
  • Generally known psittacosis or ornithosis is a disease of birds caused by the bacterium Chlamydia psittaci. Humans are accidential hosts and are most commonly infected from avian sources. It raises hepatitis or neurosis. As major outer membrane protein (MOMP) of Chlamydia psittaci has been known to play a role in the avoidance of host immune defenses, research on developing a Chlamydia vaccine has focused on the MOMP. In this study, the gene encoding the major outer membrane protein (MOMP) of the Chlamydia psittaci strain 6BC was cloned and expressed in Escherichia coli strain M-15. The recombinant DNA was cloned by fusion prokaryotic expression vector pQE30-GFPII. Expression of the recombinant protein was performed in E. coli and was induced by IPTG. The size of expressed recombinant protein is 74.220 kDa (MOMP, 43.260 kDa; GFP expression region, 30 kDa; $6{\times}His$ tag, 960Da). This protein was purified by using his-tagging-inclusion body. Recombinant protein was reconfirmed through ELISA test and western blot with antibody against pQE30-GFPII. It will be useful antibody development.

Backbone 1H, 15N, and 13C Resonance Assignments and Secondary-Structure of Conserved Hypothetical Protein HP0894 from Helicobacter pylori

  • Han, Kyung-Doo;Park, Sung-Jean;Lee, Bong-Jin
    • Molecules and Cells
    • /
    • v.20 no.3
    • /
    • pp.442-445
    • /
    • 2005
  • HP0894 (SwissProt/TrEMBL ID O25554) is an 88-residue conserved hypothetical protein from Helicobacter pylori strain 26695 with a calculated pI of 8.5 and a molecular weight of 10.38 kDa. Proteins with sequence similarity to HP0894 exist in Vibrio choierae, Enterococcus faecalis, Campylobacter jejuni, Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli O157, etc. Here we report the sequence-specific backbone resonance assignments of HP0894. About 97.5% (418/429) of the HN, N, CO, $C{\alpha}$, $C{\beta}$ resonances of the 88 residues of HP0894 were assigned. On the basis of these assignments, three helical regions and four strand regions were identified using the CSI program. This study is a prerequisite for calculating the solution structure of HP0894, and studying its interaction with its substrates, if any, and/or with other proteins.