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Discover how PEPperPRINT Peptide Microarray products have been used in different fields of research.

Nutrient transceptors physically interact with the yeast S6/protein kinase B homolog, Sch9, a TOR kinase target

Zhang, Zhiqiang; Cottignie, Ines; Van Zeebroeck, Griet; Thevelein, Johan M.
Biochem J.
Jan 2021
Multiple starvation-induced, high-affinity nutrient transporters in yeast function as receptors for activation of the protein kinase A (PKA) pathway upon re-addition of their substrate. We now show that these transceptors may play more extended roles in nutrient regulation. The Gap1 amino acid, Mep2 ammonium, Pho84 phosphate and Sul1 sulfate transceptors physically interact in vitro and in vivo with the PKA-related Sch9 protein kinase, the yeast homolog of mammalian S6 protein kinase and protein kinase B. Sch9 is a phosphorylation target of TOR and well known to affect nutrient-controlled cellular processes, such as growth rate. Mapping with peptide microarrays suggests specific interaction domains in Gap1 for Sch9 binding. Mutagenesis of the major domain affects the upstart of growth upon the addition of L-citrulline to nitrogen-starved cells to different extents but apparently does not affect in vitro binding. It also does not correlate with the drop in L-citrulline uptake capacity or transceptor activation of the PKA target trehalase by the Gap1 mutant forms. Our results reveal a nutrient transceptor–Sch9–TOR axis in which Sch9 accessibility for phosphorylation by TOR may be affected by nutrient transceptor–Sch9 interaction under conditions of nutrient starvation or other environmental challenges.

SARS-CoV-2 Epitope Mapping on Microarrays Highlights Strong Immune-Response to N Protein Region

Musicò, Angelo; Frigerio, Roberto; Mussida, Alessandro; Barzon, Luisa; Sinigaglia, Alessandro; Riccetti, Silvia; Gobbi, Federico; Piubelli, Chiara; Bergamaschi, Greta; Chiari, Marcella; Gori, Alessandro; Cretich, Marina
Vaccines.
Jan 2021
A workflow for rapid SARS-CoV-2 epitope discovery on peptide microarrays is herein reported. The process started with a proteome-wide screening of immunoreactivity based on the use of a high-density microarray followed by a refinement and validation phase on a restricted panel of probes using microarrays with tailored peptide immobilization through a click-based strategy. Progressively larger, independent cohorts of Covid-19 positive sera were tested in the refinement processes, leading to the identification of immunodominant regions on SARS-CoV-2 spike (S), nucleocapsid (N) protein and Orf1ab polyprotein. A summary study testing 50 serum samples highlighted an epitope of the N protein (region 155–71) providing good diagnostic performance in discriminating Covid-19 positive vs. healthy individuals. Using this epitope, 92% sensitivity and 100% specificity were reached for IgG detection in Covid-19 samples, and no cross-reactivity with common cold coronaviruses was detected. Likewise, IgM immunoreactivity in samples collected within the first month after symptoms onset showed discrimination ability. Overall, epitope 155–171 from N protein represents a promising candidate for further development and rapid implementation in serological tests.

Marker Sequences for Diagnosing and Stratifying Systemic Sclerosis Patients

Budde, Petra
Jan 2021
The present invention relates to methods for identifying markers for systemic sclerosis (also scleroderma; SSc) and to the markers identified with the aid of this method, which can differentiate between SSc and other autoimmune diseases on the one hand and between different SSc subgroups on the other hand. The invention also relates to panels, diagnostic devices and test kits which comprise these markers, and to the use and application thereof, for example for the diagnosis, prognosis and therapy control of SSc. The invention also relates to methods for screening and for validating active substances for use in SSc.

Molecular mimicry, genetic homology, and gene sharing proteomic “molecular fingerprints” using an EBV (Epstein-Barr virus)-derived microarray as a potential diagnostic method in autoimmune disease

Dreyfus, David H.; Farina, Antonella; Farina, Giuseppina Alessandra
Immunol Res.
Dec 2018
EBV (Epstein-Barr Virus) and other human DNA viruses are associated with autoimmune syndromes in epidemiologic studies. In this work, immunoglobulin G response to EBV-encoded proteins which share regions with human immune response proteins from the human host including ZEBRA (BZLF-1 encoded protein), BALF-2 recombinase expressed primarily during the viral lytic replication cycle, and EBNA-1 (Epstein-Barr Virus Nuclear Antigen) expressed during the viral latency cycle respectively were characterized using a laser-printed micro-array (PEPperprint.com). IgG response to conserved “A/T hooks” in EBV-encoded proteins such as EBNA-1 and the BALF-2 recombinase related to host DNA-binding proteins including RAG-1 recombinase and histones, and EBV-encoded virokines such as the IL-10 homologue BCRF-1 suggest further directions for clinical research. The author suggests that proteomic “molecular fingerprints” of the immune response to viral proteins shared with human immune response genes are potentially useful in early diagnosis and monitoring of autoantibody production and response to therapy in EBV-related autoimmune syndromes.

Soybean Allergy Related Epitopes

Kern, Karolin; Spiegel, Holger; Havenith, Heide; Szardenings, Michael
Nov 2018
The invention relates to a compilation comprising at least five different peptides, each peptide comprising at least one sequence element corresponding to an epitope selected from the group consisting of SEQ ID NO.: 1-354, wherein at least five different epitopes are represented. The invention further relates to an in vitro method for determining a patient’s immune status to soybean allergens, to a method for detecting at least one soybean allergen in a substance and to a method for determining the allergenicity of a soybean variety. Additionally, the invention relates to a kit comprising at least one composition containing a compound comprising at least five different sequence elements each corresponding to an epitope selected from the group consisting of SEQ ID NO.: 1-354, wherein at least five different epitopes are represented. Furthermore, the invention relates to the use of a peptide comprising a sequence element corresponding to an epitope for providing a molecule binding to a protein or peptide comprising the epitope.

Linear epitopes in Onchocerca volvulus vaccine candidate proteins and excretory-secretory proteins

Lagatie, Ole; Verheyen, Ann; Van Dorst, Bieke; Batsa Debrah, Linda; Debrah, Alex; Stuyver, Lieven J.
Parasite Immunol.
Nov 2018
In our previous study, a proteome-wide screen was conducted to identify linear epitopes in this parasite’s proteome, resulting in the discovery of three immunodominant motifs. Here, we investigated whether such antigenic peptides were found in proteins that were already known as vaccine candidates and excretome/secretome proteins for Onchocerca volvulus This approach led to the identification of 71 immunoreactive stretches in 46 proteins. A deep-dive into the immunoreactivity profiles of eight vaccine candidates that were chosen as most promising candidates for further development (Ov-CPI-2, Ov-ALT-1, Ov-RAL-2, Ov-ASP-1, Ov-103, Ov-RBP-1, Ov-CHI-1, and Ov-B20), resulted in the identification of a poly-glutamine stretch in Ov-RAL-2 that has properties for use as a serodiagnostic marker for O. volvulus infection. A peptide ELISA was developed, and the performance of this assay was evaluated. Based on this assessment, it was found that this assay has a sensitivity of 75.0% [95% CI: 64.9%-83.5%] and a specificity of 98.5% [95% CI: 94.6%-99.8%]. Furthermore, 8.7% reactivity in Asian parasite-infected individuals (8 out of 92) was observed. Besides this identification of a linear epitope marker, the information on the presence of linear epitopes in vaccine candidate proteins might be useful in the study of vaccines for river blindness.

Potential therapeutic antibodies targeting specific adiponectin isoforms in rheumatoid arthritis

Lee, Yeon-Ah; Hahm, Dae-Hyun; Kim, Jung Yeon; Sur, Bonjun; Lee, Hyun Min; Ryu, Chun Jeih; Yang, Hyung-In; Kim, Kyoung Soo
Arthritis Res Ther.
Oct 2018
Background Different adiponectin isoforms appear to be differentially involved in the pathogenesis of various diseases. The purpose of this study was to generate monoclonal antibodies (mAbs) specific to different adiponectin isoforms and investigate whether these mAbs have potential as therapeutic agents for such diseases. Methods Hybridoma cells producing monoclonal antibodies were generated and screened using enzyme-linked immunosorbent assay and Western blotting for the production of mAbs recognizing human adiponectin isoforms. Results The mAb from hybridoma clone KH7–41 recognized both the middle molecular weight (MMW) (hexamer) and low molecular weight (LMW) (trimer) isoforms of adiponectin in human serum, whereas the KH7–33 mAb detected only MMW (hexamer) adiponectin. The KH4–8 clone recognized both the high molecular weight (HMW) (multimer) and MMW adiponectin isoforms. However, in mouse and rat sera, the abovementioned antibodies recognized only the MMW isomer. These mAbs also recognized adiponectin in various human tissues, such as lung, kidney, and adipose tissues, although the three mAbs had different staining intensities. The mAb from clone KH4–8 effectively inhibited increases in interleukin-6 (IL-6) and IL-8 expression in recombinant adiponectin-stimulated human osteoblasts and human umbilical vein endothelial cells. Also, the mAbs KH7–33 and KH4–8 significantly ameliorated rheumatic symptoms in a collagen-induced arthritis mouse model. This result suggests that these mAb treatments may ameliorate adiponectin-mediated inflammatory response. Conclusions mAbs against human adiponectin isomers can potentially be developed as therapeutic antibodies to target specific detrimental isoforms of adiponectin while maintaining the functions of beneficial isoforms.

Generation and characterization of monoclonal antibodies that recognize human and murine supervillin protein isoforms

Smith, Tara C.; Saul, Richard G.; Barton, Elisabeth R.; Luna, Elizabeth J.
PLoS ONE.
Oct 2018
Supervillin isoforms have been implicated in cell proliferation, actin filament-based motile processes, vesicle trafficking, and signal transduction. However, an understanding of the roles of these proteins in cancer metastasis and physiological processes has been limited by the difficulty of obtaining specific antibodies against these highly conserved membrane-associated proteins. To facilitate research into the biological functions of supervillin, monoclonal antibodies were generated against the bacterially expressed human supervillin N-terminus. Two chimeric monoclonal antibodies with rabbit Fc domains (clones 1E2/CPTC-SVIL-1; 4A8/CPTC-SVIL-2) and two mouse monoclonal antibodies (clones 5A8/CPTC-SVIL-3; 5G3/CPTC-SVIL-4) were characterized with respect to their binding sites, affinities, and for efficacy in immunoblotting, immunoprecipitation, immunofluorescence microscopy and immunohistochemical staining. Two antibodies (1E2, 5G3) recognize a sequence found only in primate supervillins, whereas the other two antibodies (4A8, 5A8) are specific for a more broadly conserved conformational epitope(s). All antibodies function in immunoblotting, immunoprecipitation and in immunofluorescence microscopy under the fixation conditions identified here. We also show that the 5A8 antibody works on immunohistological sections. These antibodies should provide useful tools for the study of mammalian supervillins.

Interaction of the Warsaw breakage syndrome DNA helicase DDX11 with the replication fork-protection factor Timeless promotes sister chromatid cohesion

Cortone, Giuseppe; Zheng, Ge; Pensieri, Pasquale; Chiappetta, Viviana; Tatè, Rosarita; Malacaria, Eva; Pichierri, Pietro; Yu, Hongtao; Pisani, Francesca M.
PLoS Genet.
Oct 2018
Establishment of sister chromatid cohesion is coupled to DNA replication, but the underlying molecular mechanisms are incompletely understood. DDX11 (also named ChlR1) is a super-family 2 Fe-S cluster-containing DNA helicase implicated in Warsaw breakage syndrome (WABS). Herein, we examined the role of DDX11 in cohesion establishment in human cells. We demonstrated that DDX11 interacts with Timeless, a component of the replication fork-protection complex, through a conserved peptide motif. The DDX11-Timeless interaction is critical for sister chromatid cohesion in interphase and mitosis. Immunofluorescence studies further revealed that cohesin association with chromatin requires DDX11. Finally, we demonstrated that DDX11 localises at nascent DNA by SIRF analysis. Moreover, we found that DDX11 promotes cohesin binding to the DNA replication forks in concert with Timeless and that recombinant purified cohesin interacts with DDX11 in vitro. Collectively, our results establish a critical role for the DDX11-Timeless interaction in coordinating DNA replication with sister chromatid cohesion, and have important implications for understanding the molecular basis of WABS.

Combinatorial Synthesis of Macromolecular Arrays by Microchannel Cantilever Spotting (µCS)

Atwater, Jordyn; Mattes, Daniela S.; Streit, Bettina; von Bojničić-Kninski, Clemens; Loeffler, Felix F.; Breitling, Frank; Fuchs, Harald; Hirtz, Michael
Adv. Mater..
Aug 2018
Surface-bound microarrays of multiple oligo- and macromolecules (e.g., peptides, DNA) offer versatile options in biomedical applications like drug screening, DNA analysis, or medical diagnostics. Combinatorial syntheses of these molecules in situ can save significant resources in regard to processing time and material use. Furthermore, high feature densities are needed to enable high-throughput and low sample volumes as generally regarded in combinatorial chemistry. Here, a scanning-probe-lithography-based approach for the combinatorial in situ synthesis of macromolecules is presented in microarray format. Feature sizes below 40 µm allow for the creation of high-density arrays with feature densities of 62 500 features per cm2. To demonstrate feasibility of this approach for biomedical applications, a multiplexed array of functional protein tags (HA- and FLAG-tag) is synthesized, and selective binding of respective epitope recognizing antibodies is shown. This approach uses only small amounts of base chemicals for synthesis and can be further parallelized, therefore, opening up a route to flexible, highly dense, and cost-effective microarrays.

Universal detection of foot and mouth disease virus based on the conserved VP0 protein

Loureiro, Silvia; Porta, Claudine; Maity, Hemanta K.; Perez, Eva; Bagno, Flavia F.; Kotecha, Abhay; Fry, Elizabeth; Ren, Jingshan; Stuart, David I.; Hoenemann, Holger; Serrano, Amaya; van den Born, Erwin; Charleston, Bryan; Jones, Ian M.
Wellcome Open Res.
Jul 2018
Background : Foot and mouth disease virus (FMDV), a member of the picornaviridae that causes vesicular disease in ungulates, has seven serotypes and a large number of strains, making universal detection challenging. The mature virion is made up of 4 structural proteins, virus protein (VP) 1 – VP4, VP1-VP3 of which form the outer surface of the particle and VP4 largely contained within. Prior to mature virion formation VP2 and VP4 occur together as VP0, a structural component of the pre-capsid which, as a result of containing the internal VP4 sequence, is relatively conserved among all strains and serotypes. Detection of VP0 might therefore represent a universal virus marker. Methods : FMDV virus protein 0 (VP0) was expressed in bacteria as a SUMO fusion protein and the SUMO carrier removed by site specific proteolysis. Rabbit polyvalent sera were generated to the isolated VP0 protein and their reactivity characterised by a number of immunoassays and by epitope mapping on peptide arrays. Results : The specific VP0 serum recognised a variety of FMDV serotypes, as virus and as virus-like-particles, by a variety of assay formats. Epitope mapping showed the predominant epitopes to occur within the unstructured but highly conserved region of the sequence shared among many serotypes. When immunogold stained VLPs were assessed by TEM analysis they revealed exposure of epitopes on the surface of some particles, consistent with particle breathing hitherto reported for some other picornaviruses but not for FMDV. Conclusion : A polyvalent serum based on the VP0 protein of FMDV represents a broadly reactive reagent capable of detection of many if not all FMDV isolates. The suggestion of particle breathing obtained with this serum suggests a reconsideration of the FMDV entry mechanism.

Detecting agents and epitopes mapping for detecting glycogen phosphorylase isoenzyme bb

Kapetanovic, Ernest; Yastas, Samir
Jul 2018
Described are an oligopeptide sequence of any of RDHLVGRWIR (E1), IRRFKSSKFGCR (E2), RHLEIIYAINQR (E3). LIIKLVT (E4), WGDRLKVIF (E5), any combination of E1 to E3; or combination of E4 and E5. Further described is a detecting agent for specific detecting glycogen phosphorylase iso-enzyme BB (GPBB), wherein the detecting agent is characterized by specific recognizing and binding to (1) an epitope of the GPBB comprising an oligo-peptide sequence of any of RDHLVGRWIR (E1), IRRFKSSKFGCR (E2), RHLEIIYAINQR (E3) or any combination of E1 to E3; or (2)an epitope of GPBB comprising an oiigo-peptide sequence of LIIKLVT (E4), and/or WGDRLKVIF (E5), or combination of E4 and E5.

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