Our understanding of the cell membrane has rapidly changed in recent years with improved technologies providing better insight into the organization and structure of various components and domains that form an integral part of the membrane. Efforts are now underway to selectively identify and target membrane domains, particularly membrane proteins, to disrupt their structural integrity or function, thereby leading to the desired downstream effects in the cell. However, membrane proteins are yet to be fully exploited as drug targets, partly because they are very difficult to express and work with. Cambridge Healthtech Institute’s second annual conference on Targeting Membrane Proteins brings together experts from all areas of drug discovery and translational research to talk about ways in which different classes of membrane proteins can be explored as drug targets for new therapeutic indications. Scientists from pharma/biotech, as well as from academic and government labs, will share their findings on which membrane proteins have been targeted effectively, how they have been screened and characterized, and what therapeutic applications are being looked at.

Final Agenda

Thursday, June 16

11:00 am Registration.

12:00 pm Bridging Luncheon Presentation (Sponsorship Opportunity Available) or Enjoy Lunch on Your Own

12:30 Session Break

1:00 Coffee and Dessert in the Exhibit Hall with Poster Viewing

1:45 PLENARY KEYNOTE SESSION

3:30 Refreshment Break in the Exhibit Hall with Poster Viewing

ANTIBODY-BASED PHENOTYPIC SCREENING FOR ONCOLOGY TARGETS

4:15 Chairperson’s Opening Remarks

Karl Griswold, Ph.D., Associate Professor of Engineering, Thayer School of Engineering, Dartmouth College

4:25 Generation of Therapeutic Antibodies Targeting Heparan Sulfate Proteoglycans

Mitchell Ho, Ph.D., Senior Investigator, Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, NIH

We have developed human monoclonal antibodies that preferentially seek out functional cavities and poorly exposed epitopes on tumor-specific heparan sulfate proteoglycans. By combining cutting-edge antibody technology with cellular functional assays, we have generated inhibitory antibodies that target glypican-3. The antibodies have the unique ability to inactivate key signaling pathways (Wnt/Yap) known to be important for liver cancer pathogenesis.

5:05 Ultra-High Throughput Screening of Soluble, Secreted mAbs against Intact Cancer Cells

Karl Griswold, Ph.D., Associate Professor of Engineering, Thayer School of Engineering, Dartmouth College

We have developed an ultra-high throughput screening platform enabling identification and isolation of library clones secreting soluble monoclonal antibodies able to bind membrane proteins on the surface of intact target cells. By combining hydrogel microdroplet cell encapsulation with high speed flow cytometry, we demonstrate recovery of rare clones producing IgG binders to membrane targets such as EGFR. The technology is broadly applicable to virtually any affinity ligand format and any cell surface target.

5:45 A 3D Matrix Platform for the Rapid Generation of Therapeutic Anti-Human Carcinoma Monoclonal Antibodies

Stephen J. Weiss, M.D., Upjohn Professor of Internal Medicine and Oncology, Department of Internal Medicine, Research Professor, Life Sciences Institute, University of Michigan

As only invasive carcinoma cells access type I collagen-rich interstitial tissues in vivo, an experimental platform was established in which human carcinoma cells were embedded in 3D collagen matrices and used as immunogens to generate mAb libraries. Cancer cell-reactive antibodies were demonstrated to inhibit tumor proliferation and metastatic activity with target antigens identified by mass-spectroscopy. Immunohistochemical analyses of tissues from cancer patients verified markedly increased expression of the target antigen in vivo, thus validating the utility of this approach.

6:25 Close of Day

6:30 Dinner Short Course Registration.

7:00 - 9:30 Dinner Short Courses

Friday, June 17

7:15 am Registration Open

NEW TOOLS FOR FUNCTIONAL SCREENING AND CHARACTERIZATION

8:35 Chairperson’s Remarks

James U. Bowie, Ph.D., Professor and Vice Chair, Department of Chemistry and Biochemistry, University of California, Los Angeles

8:45 GPCR Profiling: From Hits to Leads and from Genotype to Phenotype

Mary Ellen Cvijic, Ph.D., Principal Scientist, Department of Lead Discovery and Optimization, Bristol-Myers Squibb

GPCRs remain one of the most important classes of drug targets. Hence, GPCR assay development and high-throughput GPCR ligand profiling continue to be major efforts in drug discovery. This talk focuses on GPCR platform strategies from hits to leads with miniaturized complex pharmacology approaches. Three main areas of GPCR profiling are discussed including pharmacologically relevant hit identification, the pharmacology dossier applied to parallel structure activity and structure liability relationships and high-throughput mechanism studies from genotype to phenotype.

9:15 Measuring Kinetics of Small Molecule Binding to Membrane Proteins

Nongjian Tao, Ph.D., Director, Center for Bioelectronics and Biosensors, Biodesign Institute and Professor of Electrical Engineering, Arizona State University

Measuring small molecule interactions with membrane proteins on cells in real-time is important for drug discovery and screening. This is because most drugs are small molecules and most drug targets are membrane proteins. Despite the importance, developing such a capability has been a difficult challenge. We will discuss new label-free technologies that can detect and quantify the interactions of both larger and small molecules with membrane proteins on intact cells.

9:45 Harnessing TruBind™ Technology to Enable Label-Free, Solution-Based Affinity Measurements for GPCR Target Engagement and MOA Studies

Richard Isaacs, Ph.D., Applied Research Sciences Manager, Molecular Sensing, Inc.

GPCRs are critical targets for drug discovery but present a host of challenges to the characterization of their binding affinity for small molecules. Verification of target engagement by putative GCPR ligands and further determination of mechanism of action for agonist/antagonist/allosteric compounds is especially valuable and extremely challenging information to obtain by established binding assay platforms, but can be addressed through the label-free solution-based TruBind platform based on back-scattering interferometry.

10:15 Coffee Break in the Exhibit Hall. Last Chance for Poster Viewing.

11:00 Toward Quantitative Folding Studies of Complex Membrane Proteins

James U. Bowie, Ph.D., Professor and Vice Chair, Department of Chemistry and Biochemistry, University of California, Los Angeles

Tens of thousands of mutations have now been associated with diseases and it is thought that most of these mutations affect protein folding rather than function. Yet when mutations affect membrane proteins, we are generally bereft of techniques for examining folding defects. I will summarize the state of folding experiments and describe single molecule methods we are developing to extend folding studies to complex human membrane proteins.

11:30 A Membrane-Mediated Mechanism for Polypharmacology

Olaf S. Andersen, M.D., Professor, Department of Physiology and Biophysics, Weill Medical College, Cornell University

Membrane proteins are coupled to their host lipid bilayer through hydrophobic interactions that minimize the exposure of hydrophobic surfaces to water. Consequently, the proteins’ conformational preference varies with changes in bilayer elastic properties. This provides for a usually ignored, mechanism by which amphiphilic drugs regulate membrane protein function because amphiphiles generally alter bilayer properties, and thus membrane protein function, which provides a mechanism for polypharmacology.

12:00 pm Coordinated Interactions of Membrane Receptors at TM4SF5 Enriched Microdomain for Migration Directionality

Jung Weon Lee, Ph.D., Professor, Department of Pharmacy, College of Pharmacy, Seoul National University

Dynamic interactions of tetraspanins with diverse membrane receptors at tetraspanin-enriched microdomains on cellular surfaces remain largely unexplored. Here we investigated effects of tetraspan(in) TM4SF5-enriched microdomains on directionality of cell migration. Physical association of TM4SF5 with EGF receptor and integrin α5 was visualized at the leading surface of migratory cells. We show here for the first time that TM4SF5 dynamically coordinates interactions with EGFR and integrin α5 to control migration directionality.

12:30 Luncheon Presentation (Sponsorship Opportunity Available) or Enjoy Lunch on Your Own

12:45 Session Break

APPROACHES FOR BETTER EXPRESSION AND STRUCTURAL DETERMINATION

1:30 Chairperson’s Remarks

Andrew Alt, Ph.D., Senior Research Investigator, Lead Discovery, Bristol-Myers Squibb

1:50 How Structure Begins: The Folding and Assembly of Membrane Proteins (MP)

Stephen H. White, Ph.D., Professor, Department of Physiology and Biophysics, School of Medicine, University of California at Irvine

Because of the slow rate of progress in structure determination and the importance of MPs as drug targets, the prediction of 3D structure from sequence remains a significant and pressing goal. MP structure prediction requires a molecular understanding of (1) the thermodynamic stability of proteins in the unexpectedly complex environment of the lipid bilayer and (2) the rules the translocon assembly apparatus follows during the assembly of MPs.

2:35 Journey to the High-Resolution Structure of an Ion Channel

Hao Chen, Ph.D., Senior Scientist, Protein Technologies, Amgen, Inc.

Our understanding of membrane proteins often lags behind because of their highly hydrophobic nature and their intricate structural flexibility and dynamics, which renders carrying out functional and structural studies on membrane proteins a daunting task. Here, I present some approaches we took to address the difficulties in expressing membrane proteins, which led to the determination of novel structures of a human ion channel. These high-resolution structures allow us to explore in detail the molecular mechanisms of channel modulation by agonists and antagonists.

3:05 Refreshment Break

NOVEL BIOLOGICAL STRATEGIES TO TARGET AND PROBE PROTEINS

3:20 Drugging Undruggable Membrane Protein Interactions

Hang Hubert Yin, Ph.D., Associate Professor, Department of Chemistry and Biochemistry, University of Colorado, Boulder

We have developed a generally applicable method to study the protein association of previously inaccessible integral membrane proteins. Using synthetic peptide-based probes, we reported a novel mechanism of Latent membrane protein 1 (LMP-1), a 6-pass transmembrane protein, activation that is responsible for its oncogenic activities, particularly in human Epstein-Barr virus (EBV)-associated lymphoid malignancies. These studies demonstrated a new strategy to identify small molecule disruptors for investigating multi-spanning transmembrane protein-protein interactions.

3:50 Aptamers: The Future of Cell-Targeted Bio-Drugs

Paloma H. Giangrande, Ph.D., Associate Professor, Department of Internal Medicine and Department of Radiation Oncology, University of Iowa

Treatment of some cancers has dramatically improved with the development of cell-targeted therapies directed at membrane proteins expressed on the cancer cells. However, most diseases are currently not treated with cell-targeted technology due to the paucity of established cell surface biomarkers and targeting methodologies. We will present recent advances in aptamer selection technology for simultaneously identifying novel targeting ligands (aptamers) and biomarkers on diseased cells. We will present aptamers for treatment of cancer and hyperplastic vascular diseases.

4:20 Allosterism: Can Chemistry Help Shed Light on Disease Etiology?

Dario Doller, Ph.D., Senior Director, Deuterium Platform, Concert Pharmaceuticals, Inc.

Enhancing the translational value of preclinical ADMET tests helped reducing the risk of early clinical attrition. Will this strategy help predict clinical efficacy for unprecedented targets? Observations obtained working with allosteric modulators suggest ways to produce mechanistic, translatable information on drug efficacy, which may especially impact membrane-bound biological targets, often key for CNS disease hypotheses.

4:50 Close of Conference