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

Molecular and Serological Tests for COVID-19. A Comparative Review of SARS-CoV-2 Coronavirus Laboratory and Point-of-Care Diagnostics

Kubina, Robert; Dziedzic, Arkadiusz
Validated and accurate laboratory testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a crucial part of the timely management of Coronavirus Disease 2019 (COVID-19) disease, supporting the clinical decision-making process for infection control at the healthcare level and detecting asymptomatic cases. This would facilitate an appropriate treatment, a prompt isolation and consequently deceleration of the pandemic. Various laboratory tests can identify the genetic material of SARS-CoV-2 that causes COVID-19 in specimens, or specific anti-viral antibodies in blood/serum. Due to the current pandemic situation, a development of point-of-care diagnostics (POCD) allows us to substantially accelerate taking clinical decisions and implement strategic planning at the national level of preventative measures. This review summarizes and compares the available POCD and those currently under development, including quantitative reverse transcription PCR (RT-qPCR), serology immunoassays (SIAs) and protein microarray method (PMM) designed for standard and rapid COVID-19 diagnosis.

On‐Chip Neo‐Glycopeptide Synthesis for Multivalent Glycan Presentation

Mende, Marco; Tsouka, Alexandra; Heidepriem, Jasmin; Paris, Grigori; Mattes, Daniela S.; Eickelmann, Stephan; Bordoni, Vittorio; Wawrzinek, Robert; Fuchsberger, Felix F.; Seeberger, Peter H.; Rademacher, Christoph; Delbianco, Martina; Mallagaray, Alvaro; Loeffler, Felix F
Chem. Eur. J..
Apr 2020
Single glycan–protein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. By combining this technique with click chemistry, neo-glycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in well-defined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding.

Autoantibody Signature in Cardiac Arrest

Maguy, Ange; Tardif, Jean-Claude; Busseuil, David; Ribi, Camillo; Li, Jin
Circulation.
Apr 2020
Background: Cardiac arrest is a tragic event that causes one death roughly every 90 seconds worldwide. Survivors generally undergo a work-up to identify the etiology of arrest. However, 5-10% of cardiac arrest remain unexplained. As cardiac arrhythmias mostly underlie cardiac arrest and increasing evidence strongly supports the involvement of autoantibodies in arrhythmogenesis, a large-panel autoantibody screening was performed in cardiac arrest patients. Methods: This is an observational, cross-sectional study of patients from the Montreal Heart Institute (MHI) hospital cohort, a single center registry of participants. A peptide microarray was designed to screen for IgG targeting epitopes from all known cardiac ion channels with extracellular domains. Plasma samples from 23 patients with unexplained cardiac arrest were compared to 22 cardiac arrest cases of ischemic origin and a group of 29 age-, sex- and BMI-matched healthy subjects. The false discovery rate (FDR), LASSO logistic regression and random forest methods were jointly carried out to find significant differential IgG responses. Results: The autoantibody against the pore domain of the L-type voltage-gated calcium channel (Ca v 1.2) was consistently identified as a biomarker of idiopathic cardiac arrest (P=0.002, FDR=0.007, classification accuracies ≥0.83). Functional studies on human induced pluripotent stem cell-derived cardiomyocytes demonstrated that the anti-Ca v 1.2 IgG purified from patients with idiopathic cardiac arrest is proarrhythmogenic by reducing the action potential duration through calcium channel inhibition. Conclusions: The present report addresses the concept of autoimmunity and cardiac arrest. Hitherto unknown autoantibodies targeting extracellular sequences of cardiac ion channels were detected. Moreover, the study identified an autoantibody signature specific to patients with cardiac arrest.

Plasmodium Falciparum and Plasmodium Vivax Vaccine

Werner, Ekkehard
Apr 2020
The present invention relates to a vaccine V comprising (A) at least one isolated polypeptide strand P comprising or consisting of at least nine consecutive amino acid moieties of the repetitive organellar protein, putative of Plasmodium falciparum or the hypothetical protein PVNG_04523 of Plasmodium vivax or a polynucleotide strand encoding for such polypeptide; and (B) at least one pharmaceutically acceptable carrier or excipient. Furthermore, the present invention refers to an antibody binding to the repetitive organellar protein,putative of Plasmodium falciparumor the hypothetical protein PVNG_04523 of Plasmodium vivax or a polynucleotide strand encoding therefor, to a method of generating such antibody and uses thereof.

Potent Adjuvanticity of a Pure TLR7-Agonistic Imidazoquinoline Dendrimer

Shukla, Nikunj M.; Salunke, Deepak B.; Balakrishna, Rajalakshmi; Mutz, Cole A.; Malladi, Subbalakshmi S.; David, Sunil A.
PLoS ONE.
Aug 2012
Engagement of toll-like receptors (TLRs) serve to link innate immune responses with adaptive immunity and can be exploited as powerful vaccine adjuvants for eliciting both primary and anamnestic immune responses. TLR7 agonists are highly immunostimulatory without inducing dominant proinflammatory cytokine responses. We synthesized a dendrimeric molecule bearing six units of a potent TLR7/TLR8 dual-agonistic imidazoquinoline to explore if multimerization of TLR7/8 would result in altered activity profiles. A complete loss of TLR8-stimulatory activity with selective retention of the TLR7-agonistic activity was observed in the dendrimer. This was reflected by a complete absence of TLR8-driven proinflammatory cytokine and interferon (IFN)-γ induction in human PBMCs, with preservation of TLR7-driven IFN-α induction. The dendrimer was found to be superior to the imidazoquinoline monomer in inducing high titers of high-affinity antibodies to bovine α-lactalbumin. Additionally, epitope mapping experiments showed that the dendrimer induced immunoreacti

Sensing Immune Responses with Customized Peptide Microarrays

Schirwitz, Christopher; Loeffler, Felix F.; Felgenhauer, Thomas; Stadler, Volker; Breitling, Frank; Bischoff, F. Ralf
Biointerphases.
Aug 2012
The intent to solve biological and biomedical questions in high-throughput led to an immense interest in microarray technologies. Nowadays, DNA microarrays are routinely used to screen for oligonucleotide interactions within a large variety of potential interaction partners. To study interactions on the protein level with the same efficiency, protein and peptide microarrays offer similar advantages, but their production is more demanding. A new technology to produce peptide microarrays with a laser printer provides access to affordable and highly complex peptide microarrays. Such a peptide microarray can contain up to 775 peptide spots per cm², whereby the position of each peptide spot and, thus, the amino acid sequence of the corresponding peptide, is exactly known. Compared to other techniques, such as the SPOT synthesis, more features per cm² at lower costs can be synthesized which paves the way for laser printed peptide microarrays to take on roles as efficient and affordable biomedical sensors. Here, we describe the laser printer-based synthesis of peptide microarrays and focus on an application involving the blood sera of tetanus immunized individuals, indicating the potential of peptide arrays to sense immune responses.

Physical Characterization of the “Immunosignaturing Effect”

Stafford, Phillip; Halperin, Rebecca; Legutki, Joseph Bart; Magee, Dewey Mitchell; Galgiani, John; Johnston, Stephen Albert
Mol Cell Proteomics.
Apr 2012
Identifying new, effective biomarkers for diseases is proving to be a challenging problem. We have proposed that antibodies may offer a solution to this problem. The physical features and abundance of antibodies make them ideal biomarkers. Additionally, antibodies are often elicited early in the ontogeny of different chronic and infectious diseases. We previously reported that antibodies from patients with infectious disease and separately those with Alzheimer’s disease display a characteristic and reproducible immunosignature on a microarray of 10,000 random sequence peptides. Here we investigate the physical and chemical parameters underlying how immunosignaturing works. We first show that a variety of monoclonal and polyclonal antibodies raised against different classes of antigens produce distinct profiles on this microarray and the relative affinities are determined. A proposal for how antibodies bind the random sequences is tested. Sera from vaccinated mice and people suffering from a fugal infection are individually assayed to determine the complexity of signals that can be distinguished. Based on these results, we propose that this simple, general and inexpensive system could be optimized to generate a new class of antibody biomarkers for a wide variety of diseases.

Combinatorial Synthesis of Peptide Arrays onto a Microchip

Beyer, M.; Nesterov, A.; Block, I.; Konig, K.; Felgenhauer, T.; Fernandez, S.; Leibe, K.; Torralba, G.; Hausmann, M.; Trunk, U.; Lindenstruth, V.; Bischoff, F. R.; Stadler, V.; Breitling, F.
Science.
Dec 2007
Arrays promise to advance biology through parallel screening for binding partners. We show the combinatorial in situ synthesis of 40,000 peptide spots per square centimeter on a microchip. Our variant Merrifield synthesis immobilizes activated amino acids as monomers within particles, which are successively attracted by electric fields generated on each pixel electrode of the chip. With all different amino acids addressed, particles are melted at once to initiate coupling. Repetitive coupling cycles should allow for the translation of whole proteomes into arrays of overlapping peptides that could be used for proteome research and antibody profiling.

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