GFP-Trap

What Does It Take to Bring New Nano Antibodies (nAbs) to the Hands of Researchers?

Judging from the hundreds of papers published using camelid VHH antibodies as reagents, there are probably thousands of researchers who have experience with this type of antibodies by now. We like to call the ~15kD camelid VHH antibody nano antibody or nAbTM. Once someone experiences how well a nAb works for co-IP using a fluorescent protein as tag, they often wonder what it takes to bring nAbs to broader use.

The success of a nAb project starts with the antigen presentation. It is critical to build the capability to produce large quantities of recombinant antigen for immunization. At Allele, our scientists also established some unique presentation formats for traditionally difficult targets (e.g. large membrane proteins).

After llama immunization, the next step is screening. With the goal of creating large scale nano antibodies against diverse targets, we have developed multiple high throughput screening methods to cover very large, diverse libraries generated from immunized animals. The technologies will continue to evolve as the scale of nAb generation continues to expand. We have the ability to functionally screen for site-blocking antibodies and antibodies that only recognized natively folded targets, or targets in their naturally occurring presentations.

A nAb isolation project does not end with the obtaining of a cDNA clone. Or, if it does, the nAb is probably not as great as what Allele Biotech has been offering. In our hands, all nAbs go through an engineering step beginning with the generation of a 3D structural model of the isolated clone. We use structure-guided design to alter the protein, allowing us to improve its properties. This includes increasing affinity, solubility, or altering the protein to improve performance for specific applications. We also like to use known structures of traditional monoclonal antibodies to assist camelid VHH antibody engineering against specific targets.

With a finalized clone in hand, the next step is to establish protocols for commercial production. The Allele team spends a tremendous amount of effort aimed solely at high-yield, low-cost recombinant VHH antibody production in a variety of formats, so that the costs for other scientists to take advantage of these great reagents can be kept as low as possible.

Last but not the least, nAb labeling, including conjugating stable soluble VHH antibody to solid supports for immunoprecipitation or to fluorophores for detection, requires additional expertise and tight operation control. However, our vision is to have a modular system for antibody labeling that will enable the end user to select from a variety of fluorophores and other detection tags, which can be instantaneously and irreversibly coupled via simple mixing.

Note added: we work with commercial (diagnostic and clinical) partners from developing nAbs all the way to the market. We have expert scientists available to customers and licensees for consultation and troubleshooting antibody- and imaging-related questions and problems.

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When Great is not Good Enough—VHH Antibodies Engineered for 10 Fold Affinity Increase

Single Domain antibodies (VHH fragments, nanobodies, or as we call them, nAbs) have been generated by injecting llamas with ligand-bound GPCR for the purpose of obtaining crystals of active-state structures. Such structural information could be critical in understanding drug functions and screening for new drugs. The unique ability of VHH fragments to fit into protein-protein complex crevices and hold proteins together was demonstrated by two Nature publications from Brian Kobilka’s group at Stanford ([1, 2], also see Allele Newsletter of Sep 4th, 2013). The nano antibody used in those studies, Nb80, showed affinity towards only the active state of the target GPCR.

However, even with an antibody as great as Nb80, the authors were only able to co-crystal GPCR beta2-adrenoceptor (b2AR) with high affinity agonists, not its natural agonists such as adrenaline. In yet another Nature paper published just now, the Kobilka lab showed that Nb80 could be further improved by 10 times in affinity, through in vitro evolution [3]. They presented Nb80 on the surface of yeast using an existing yeast display system, then applied standard limited mutagenesis and magnetic separation technologies for screening. After about 5 rounds of selection, a new version of VHH Nb6B9 was isolated that bound to ligand-loaded GPCR with a kD of 6.4 nM. For the first time, a co-crystal of b2AR-adrenoline was made.

Rasmussen et al. Nature, 2011 Structure of a nanobody-stabilized active state of the b2 adrenoceptor
Rasmussen et al. Nature, 2011 Crystal structure of the b2 adrenergic receptor–Gs protein complex
Ring et al. Nature, 2013 Adrenaline-activated structure of b2-adrenoceptor stabilized by an engineered nanobody

Update here http://www.allelebiotech.com/nab

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VHH Nanobodies in Superresolution Imaging and More

From the large number of recent publications using GFP-Trap beads, it appears that GFP-Trap is on the way to becoming one the most popular tags for co-IP thanks to its unparalleled “cleanness” of precipitated protein bands and its quantitative binding capabilities. As described previously, the antibody conjugated on the GFP-Trap beads is a single-domain antigen binding module from camelid single-chain antibodies. Termed VHH, this domain is only ~12 kD and can fit into structures that other types of antibodies cannot. We have successfully created VHH antibodies against a number of neural factors as a research project for the NIDA/NIH.

VHH antibodies are often called nanobodies as a result of their size (1.5 – 2.5nm) and binding affinity ( GFP-trap has a binding affinity of 0.59nM). In addition to their use for co-IP, VHH antibodies have proven themselves as a resilient tool for various other applications. Anti-GFP nanobodies, for example, are currently used to enhance the fluorescence of GFP (GFP-trap booster utilizes the same VHH binding antibody coupled to a fluorescent dye); others have used VHH antibodies that can insert into certain part of GFP to dim the fluorescence signal . More recently, Ries et al. published in Nature Methods that the anti-GFP nanobodies offered a simple and versatile method for super-resolution imaging (i.e. PALM)-previously super-resolution imaging requires photoconvertible fluorescent proteins (such as Eos, mClavGR2). With dye-conjugated nanobodies, generating fusions to these newer FPs is no longer needed, however, using the nanobody super-imaging method requires fixing and permeabilizing the cells.

When using anti-GFP VHH reagents you need to be aware that other fluorescent proteins can also be recognized, if they were derived from the avGFP (jellyfish GFP). Also, some GFPs are not recognized if they are from another species, or engineered such as our mWasabi. We are producing newer and brighter GFP/YFPs based on the lancelet YFP protein to offer alternative series that will not be cross-recognized by the GFP-Trap antibodies.

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Record number of papers citing the GFP-Trap group products in 2011

The following are references in regards to GFP Trap published in the second half of 2011 (not a complete list); a high quality GFP-binding protein based on a single domain antibody derived from Camelids. It is characterized by a small barrel shaped structure (13 KDa, 2.5nm X 4.5 nm) and a very high stability (stable up to 70°C, functional within 2M NaCl or 0.5% SDS). With much greater stability, specificity, and affnity, GFP-Trap®, the recent addition to antibodies for immunoprecipitation, should make GFP the most suitable tag for immunoprecipitation assays.

For live PubMed links, view this version please.

Krastev, D. B., Slabicki, M., et al. (2011). A systematic RNAi synthetic interaction screen reveals a link between p53 and snoRNP assembly. Nature Cell Biology. 13: 809-818. PubMed

Aboobakar, E. F., Wang, X., et al. (2011). The C2 domain protein Cts1 functions in the calcineurin signaling circuit during high temperature stress responses in Cryptococcus neoformans. Eukaryotic Cell. EC. 05148-05111v05141. PubMed

Uhrig, R. G. and Moorhead, G. B. G. (2011). Two ancient bacterial-like PPP family phosphatases from Arabidopsis thaliana are highly conserved plant proteins that possess unique properties. Plant Physiology. PubMed

Larance, M., Kirkwood, K. J., et al. (2011). Characterization of MRFAP1 Turnover and Interactions Downstream of the NEDD8 Pathway. Molecular & Cellular Proteomics. PubMed

Hattersley, N., Shen, L., et al. (2011). The SUMO protease SENP6 is a direct regulator of PML nuclear bodies. Molecular Biology of the Cell. 22: 78-90. PubMed

Rancz, E. A., Franks, K. M., et al. (2011). Transfection via whole-cell recording in vivo: bridging single-cell physiology, genetics and connectomics. Nature Neuroscience. 14: 527-532. PubMed

Palmer, C. S., Osellame, L. D., et al. (2011). MiD49 and MiD51, new components of the mitochondrial fission machinery. EMBO reports. 12: 565-573. PubMed

Pichler, G., Wolf, P., et al. (2011). Cooperative DNA and histone binding by Uhrf2 links the two major repressive epigenetic pathways. Journal of Cellular Biochemistry. 112: 2585-2593. PubMed

Mitchell, L., Lau, A., et al. (2011). Regulation of Septin Dynamics by the Saccharomyces cerevisiae Lysine Acetyltransferase NuA4. PLoS One. 6: e25336. PubMed

Engeland, C. E., Oberwinkler, H., et al. (2011). The cellular protein Lyric interacts with HIV-1 Gag. Journal of virology. JVI. 00174-00111v00171. PubMed

Wang, C. and Youle, R. (2011). Predominant requirement of Bax for apoptosis in HCT116 cells is determined by Mcl-1′s inhibitory effect on Bak. Oncogene. PubMed

Tulloch, L. B., Howie, J., et al. (2011). The inhibitory effect of phospholemman on the sodium pump requires its palmitoylation. Journal of Biological Chemistry. 286: 36020-36031. PubMed

Sun, L. and Wang, C. C. (2011). The Structural Basis of Localizing Polo-Like Kinase to the Flagellum Attachment Zone in Trypanosoma brucei. PLoS One. 6: e27303. PubMed

Bouttier, M., Saumet, A., et al. (2011). Retroviral GAG proteins recruit AGO2 on viral RNAs without affecting RNA accumulation and translation. Nucleic acids research. PubMed

Matos, J., Blanco, M. G., et al. (2011). Regulatory Control of the Resolution of DNA Recombination Intermediates during Meiosis and Mitosis. Cell. 147: 158-172. PubMed

Nagel, C. H., Albrecht, N., et al. (2011). Herpes Simplex Virus Immediate-Early Protein ICP0 Is Targeted by SIAH-1 for Proteasomal Degradation. Journal of virology. 85: 7644. PubMed

Studencka, M., Konzer, A., et al. (2011). Novel roles of C. elegans heterochromatin protein HP1 and linker histone in the regulation of innate immune gene expression. Molecular and Cellular Biology.PubMed

Muehlen, S., Ruchaud-Sparagano, M. H., et al. (2011). Proteasome-independent Degradation of Canonical NFŒ?B Complex Components by the NleC Protein of Pathogenic Escherichia coli. Journal of Biological Chemistry. 286: 5100. PubMed

Galan, J. A., Paris, L. L., et al. (2011). Proteomic Studies of Syk-Interacting Proteins Using a Novel Amine-Specific Isotope Tag and GFP Nanotrap. Journal of the American Society for Mass Spectrometry. 1-10. PubMed

Chamousset, D., De Wever, V., et al. (2010). RRP1B Targets PP1 to Mammalian Cell Nucleoli and is Associated with Pre-60S Ribosomal Subunits. Mol Biol Cell. PubMed

Kovacs, E. M., Verma, S., et al. (2011). N-WASP regulates the epithelial junctional actin cytoskeleton through a non-canonical post-nucleation pathway. Nature Cell Biology. 13: 934-943. PubMed

Boysen, K. E. and Matuschewski, K. (2011). Arrested oocyst maturation in Plasmodium parasites lacking type II NADH: ubiquinone dehydrogenase. Journal of Biological Chemistry. 286: 32661-32671. PubMed

Mortusewicz, O., Fouquerel, E., et al. (2011). PARG is recruited to DNA damage sites through poly (ADP-ribose)-and PCNA-dependent mechanisms. Nucleic acids research. 39: 5045. PubMed

Graewe, S., Rankin, K. E., et al. (2011). Hostile takeover by Plasmodium: reorganization of parasite and host cell membranes during liver stage egress. PLoS Pathogens. 7: e1002224. PubMed

Yang, X. D., Huang, S., et al. (2011). Distinct and mutually inhibitory binding by two divergent Œ?-catenins coordinates TCF levels and activity in C. elegans. Development. 138: 4255-4265. PubMed

Pollithy, A., Romer, T., et al. (2011). Magnetosome expression of functional camelid antibody fragments (nanobodies) in Magnetospirillum gryphiswaldense. Applied and environmental microbiology. 77: 6165-6171. PubMed

Kozubowski, L., Thompson, J. W., et al. (2011). Association of Calcineurin with the COPI Protein Sec28 and the COPII Protein Sec13 Revealed by Quantitative Proteomics. PLoS One. 6: e25280. PubMed

Garcia-Gomez, J. J., Lebaron, S., et al. (2011). Dynamics of the putative RNA helicase Spb4 during ribosome assembly in Saccharomyces cerevisiae. Molecular and Cellular Biology. 31: 4156-4164. PubMed

Van Damme, D., Gadeyne, A., et al. (2011). Adaptin-like protein TPLATE and clathrin recruitment during plant somatic cytokinesis occurs via two distinct pathways. Proceedings of the National Academy of Sciences. 108: 615. PubMed

Qvist, P., Huertas, P., et al. (2011). CtIP Mutations Cause Seckel and Jawad Syndromes. PLoS Genetics. 7: e1002310. PubMed

Labella, S., Woglar, A., et al. (2011). Polo Kinases Establish Links between Meiotic Chromosomes and Cytoskeletal Forces Essential for Homolog Pairing. Developmental Cell. PubMed

Harterink, M., Port, F., et al. (2011). A SNX3-dependent retromer pathway mediates retrograde transport of the Wnt sorting receptor Wntless and is required for Wnt secretion. Nature Cell Biology. 13: 914-923. PubMed

Konopacki, F. A., Jaafari, N., et al. (2011). Agonist-induced PKC phosphorylation regulates GluK2 SUMOylation and kainate receptor endocytosis. Proceedings of the National Academy of Sciences.PubMed

Chuhma, N., Tanaka, K. F., et al. (2011). Functional connectome of the striatal medium spiny neuron. The Journal of Neuroscience. 31: 1183-1192. PubMed

Jackson, B. R., Boyne, J. R., et al. (2011). An Interaction between KSHV ORF57 and UIF Provides mRNA-Adaptor Redundancy in Herpesvirus Intronless mRNA Export. PLoS Pathogens. 7: e1002138. PubMed

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Top 10 List of Most Viewed AlleleBlogs in 2011

The ballot is in—among the “usual suspect” hot topics, iPS takes the top honor and most entries; Camelid antibodies, although not really presented as a typical AlleleBlog in 2011, made it to the top 3. shRNA cloning and RNAi screening are still on a lot of people’s minds, so it seems.

Method: total visits to each blog since our new webpage was launched in July was counted.

1) Fusion of the Transcription Domain to iPS Factors Radically Enhances Reprogramming
http://blog.allelebiotech.com/2011/10/fusion-of-the-transcription-domain-to-ips-factors-radically-enhances-reprogramming/

2) Methods of iPSC Generation Update
http://blog.allelebiotech.com/2011/08/methods-of-ipsc-generation-update/

3) About 50 Papers Cited the Use of GFP-Trap Camelid Antibody So Far in 2011
http://blog.allelebiotech.com/2011/09/about-50-papers-cited-the-use-of-gfp-trap-camelid-antibody-so-far-in-2011/

4) Big Potential in Using Protozoans for Producing Mammalian Proteins
http://blog.allelebiotech.com/2011/09/big-potential-in-using-protozoans-for-producing-mammalian-proteins/

5) How do you make shRNA-expressing viruses for function screening?
http://blog.allelebiotech.com/2011/11/how-do-you-make-shrna-expressing-viruses-for-function-screening/

6) Creating ground-state human iPSCs
http://blog.allelebiotech.com/2011/10/creating-ground-state-human-ipsc/

7) Recombinase-Mediated Cassette Exchange (RMCE) and Integrase Swappable in vivo Targeting Element (InSITE)
http://blog.allelebiotech.com/2011/03/recombinase-mediated-cassette-exchange-rmce-and-integrase-swappable-in-vivo-targeting-element-insite/

8) Development of Cell Lines from iPSCs for Bioassays
http://blog.allelebiotech.com/2011/11/development-of-cell-lines-from-ipscs-for-bioassays/

9) Choosing siRNA, shRNA, and miRNA for Gene Silencing
blog.allelebiotech.com/2010/02/choosing-sirna-shrna-and-mirna-for-gene-silencing/

10) Allele Biotech’s Box Swap Program
http://blog.allelebiotech.com/2009/07/allele-biotechs-box-swap-program/

Have a successful 2012!

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Friday, December 30th, 2011 Allele Mail Bag No Comments