scholarly journals Efficient Screening of Combinatorial Peptide Libraries by Spatially Ordered Beads Immobilized on Conventional Glass Slides

2019 ◽  
Vol 8 (2) ◽  
pp. 11
Author(s):  
Timm Schwaar ◽  
Maike Lettow ◽  
Dario Remmler ◽  
Hans G. Börner ◽  
Michael G. Weller

Screening of one-bead-one-compound (OBOC) libraries is a proven procedure for the identification of protein-binding ligands. The demand for binders with high affinity and specificity towards various targets has surged in the biomedical and pharmaceutical field in recent years. The traditional peptide screening involves tedious steps such as affinity selection, bead picking, sequencing, and characterization. Herein, we present a high-throughput “all-on-one chip” system to avoid slow and technically complex bead picking steps. On a traditional glass slide provided with an electrically conductive tape, beads of a combinatorial peptide library are aligned and immobilized by application of a precision sieve. Subsequently, the chip is incubated with a fluorophore-labeled target protein. In a fluorescence scan followed by matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF) mass spectrometry, high-affinity binders are directly and unambiguously sequenced with high accuracy without picking of the positive beads. The use of an optimized ladder sequencing approach improved the accuracy of the de-novo sequencing step to nearly 100%. The new technique was validated by employing a FLAG-based model system, identifying new peptide binders for the monoclonal M2 anti-FLAG antibody, and was finally utilized to search for IgG-binding peptides. In the present format, more than 30,000 beads can be screened on one slide.

Blood ◽  
2004 ◽  
Vol 103 (4) ◽  
pp. 1356-1363 ◽  
Author(s):  
Barbara P. Schick ◽  
David Maslow ◽  
Adrianna Moshinski ◽  
James D. San Antonio

Abstract Patients given unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) for prophylaxis or treatment of thrombosis sometimes suffer serious bleeding. We showed previously that peptides containing 3 or more tandem repeats of heparin-binding consensus sequences have high affinity for LMWH and neutralize LMWH (enoxaparin) in vivo in rats and in vitro in citrate. We have now modified the (ARKKAAKA)n tandem repeat peptides by cyclization or by inclusion of hydrophobic tails or cysteines to promote multimerization. These peptides exhibit high-affinity binding to LMWH (dissociation constant [Kd], ≈ 50 nM), similar potencies in neutralizing anti–Factor Xa activity of UFH and enoxaparin added to normal plasma in vitro, and efficacy equivalent to or greater than protamine. Peptide (ARKKAAKA)3VLVLVLVL was most effective in all plasmas from enoxaparin-treated patients, and was 4- to 20-fold more effective than protamine. Several other peptide structures were effective in some patients' plasmas. All high-affinity peptides reversed inhibition of thrombin-induced clot formation by UFH. These peptides (1 mg/300 g rat) neutralized 1 U/mL anti–Factor Xa activity of enoxaparin in rats within 1 to 2 minutes. Direct blood pressure and heart rate measurements showed little or no hemodynamic effect. These heparin-binding peptides, singly or in combination, are potential candidates for clinical reversal of UFH and LMWH in humans.


2001 ◽  
Vol 193 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Jan H. Kessler ◽  
Nico J. Beekman ◽  
Sandra A. Bres-Vloemans ◽  
Pauline Verdijk ◽  
Peter A. van Veelen ◽  
...  

We report the efficient identification of four human histocompatibility leukocyte antigen (HLA)-A*0201–presented cytotoxic T lymphocyte (CTL) epitopes in the tumor-associated antigen PRAME using an improved “reverse immunology” strategy. Next to motif-based HLA-A*0201 binding prediction and actual binding and stability assays, analysis of in vitro proteasome-mediated digestions of polypeptides encompassing candidate epitopes was incorporated in the epitope prediction procedure. Proteasome cleavage pattern analysis, in particular determination of correct COOH-terminal cleavage of the putative epitope, allows a far more accurate and selective prediction of CTL epitopes. Only 4 of 19 high affinity HLA-A*0201 binding peptides (21%) were found to be efficiently generated by the proteasome in vitro. This approach avoids laborious CTL response inductions against high affinity binding peptides that are not processed and limits the number of peptides to be assayed for binding. CTL clones induced against the four identified epitopes (VLDGLDVLL, PRA100–108; SLYSFPEPEA, PRA142–151; ALYVDSLFFL, PRA300–309; and SLLQHLIGL, PRA425–433) lysed melanoma, renal cell carcinoma, lung carcinoma, and mammary carcinoma cell lines expressing PRAME and HLA-A*0201. This indicates that these epitopes are expressed on cancer cells of diverse histologic origin, making them attractive targets for immunotherapy of cancer.


FEBS Letters ◽  
2019 ◽  
Vol 594 (3) ◽  
pp. 477-490 ◽  
Author(s):  
Flávio Sádio ◽  
Gerhard Stadlmayr ◽  
Katharina Stadlbauer ◽  
Maximilian Gräf ◽  
Agnes Scharrer ◽  
...  

2017 ◽  
Vol 114 (6) ◽  
pp. 1331-1342 ◽  
Author(s):  
Venkata Giridhar Poosarla ◽  
Tong Li ◽  
Boon Chong Goh ◽  
Klaus Schulten ◽  
Thomas K. Wood ◽  
...  
Keyword(s):  
De Novo ◽  

ChemBioChem ◽  
2003 ◽  
Vol 4 (4) ◽  
pp. 272-276 ◽  
Author(s):  
Mark Nitz ◽  
Katherine J. Franz ◽  
Rebecca L. Maglathlin ◽  
Barbara Imperiali

2001 ◽  
Vol 276 (15) ◽  
pp. 12235-12240 ◽  
Author(s):  
Ren-Hwa Yeh ◽  
Tae Ryong Lee ◽  
David S. Lawrence

A wide variety of proteins have been shown to recognize and bind to specific amino acid sequences on other proteins. These sequences can be readily identified using combinatorial peptide libraries. However, peptides containing these preferred sequences (“consensus sequence peptides”) typically display only modest affinities for the consensus sequence-binding site on the intact protein. In this report, we describe a parallel synthesis strategy that transforms consensus sequence peptides into high affinity ligands. The work described herein has focused on the Lck SH2 domain, which binds the consensus peptide acetyl-Tyr(P)-Glu-Glu-Ile-amide with aKDof 1.3 μm. We employed a strategy that creates a series of spatially focused libraries that challenge specific subsites on the target protein with a diverse array of functionality. The final lead compound identified in this study displayed a 3300-fold higher affinity for the Lck SH2 domain than the starting consensus sequence peptide.


1978 ◽  
Vol 536 (2) ◽  
pp. 429-432 ◽  
Author(s):  
Peter R. Hearn ◽  
Stephen Tomlinson ◽  
Homa Mellersh ◽  
Christopher J. Kenyon ◽  
Christopher J. Preston ◽  
...  

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