drug discovery

CRISPR/Cas9 Knock-In Tagging: Simplifying the Study of Endogenous Biology

Posted on by Ken Doyle

Understanding the expression, function and dynamics of proteins in their native environment is a fundamental goal that’s common to diverse aspects of molecular and cell biology. To study a protein, it must first be labeled—either directly or indirectly—with a “tag” that allows specific and sensitive detection.

Using a labeled antibody to the protein of interest is a common method to study native proteins. However, antibody-based assays, such as ELISAs and Western blots, are not suitable for use in live cells. These techniques are also limited by throughput and sensitivity. Further, suitable antibodies may not be available for the target protein of interest.

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Targeted Protein Degradation: How Chemoproteomics and Induced Proximity Are Shaping Drug Discovery

Posted on by Amy Landreman

Earlier this fall, more than 90 researchers from academia and industry gathered at the Promega Madison campus for the 4th TPD & Induced Proximity Symposium. The event focused on the rapidly advancing field of targeted protein degradation (TPD) and the broader concept of induced proximity—therapeutic strategies that bring two or more proteins into proximity to trigger a specific biological effect. 

This 4th year reflected of the symposium a maturing and diversifying field with chemoproteomics and proteomescale mapping redefining what it means to be “druggable,” while AI and high throughput biology are connecting molecular design to cellular function. Yet the mission remains unchanged—using molecular approaches that leverage the cellular machinery to make progress against targets once deemed “undruggable.” 

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Cellular Selectivity Profiling: Unveiling Novel Interactions and More Accurate Compound Specificity

Posted on by Promega

This blog was written by guest contributor Tian Yang, Associate Product Manager, Promega, in collaboration with Kristin Huwiler, Manager, Small Molecule Drug Discovery, Promega.

Determining the selectivity of a compound is critical during chemical probe or drug development. In the case of chemical probes, having a clearly defined mechanism of action and specific on-target activity are needed for a chemical probe to be useful in delineating the function of a biological target of interest in cells. Similarly, optimizing a drug candidate for on-target potency and reducing off-target interactions is important in the drug development process (1,2). A thorough understanding of the selectivity profile of a drug can facilitate drug repurposing, by enabling approved therapeutics to be applied to new indications (3). Interestingly, small molecule drugs do not necessarily require the same selectivity as a chemical probe, since some drugs may benefit from polypharmacology to achieve their desired clinical outcome.

Selectivity profiling panels based on biochemical methods have commonly been used to assess compound specificity for established target classes in drug discovery and chemical probe development. Biochemical assays are target-specific and often quantitative, enabling direct measurements of compound affinities for targets of interest and facilitate comparison of compound engagement to a panel of targets. As an example, several providers offer kinase selectivity profiling services using different assay formats and kinase panels comprised of 100 to 400 kinases (4). However, just as biochemical target engagement does not always translate to cellular activity, selectivity profiles based on biochemical platforms may not reflect compound selectivity in live cells (5).

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From Tracers to Kinetic Selectivity: Highlights from the Target Engagement in Chemical Biology Symposium

Posted on by Anna Bennett

In April 2024, Promega hosted the “Target Engagement in Chemical Biology Symposium” at the Kornberg Center, a research and development hub on Promega’s campus in Madison, Wisconsin. The goal of the symposium was to gather interdisciplinary researchers interested in the field of small molecule target engagement to foster collaboration through knowledge sharing and innovation. The symposium featured a 1.5-day agenda packed with 23 speakers, 4 workshops, poster sessions and social events. Over 130 attendees gathered to participate in the multifaceted event, with participants from different geographic regions and in different research sectors from academia to government to industry.  

People gather in a large atrium with scientific posters and table displays.
Attendees gather for the poster session in Kornberg Atrium. Photo by Anna Bennett (Promega Corporation)

The symposium highlighted the collective commitment to overcoming the challenges in drug discovery by developing more targeted and efficacious treatments, driven by a shared determination to create innovative solutions that address unmet medical needs. While we cannot share all the exciting research presented at the symposium, we are thrilled to highlight a few talks that exemplify the novel work and collaborative spirit of this research community.  

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Can AI Replace High-Throughput Screens for Drug Discovery?

Posted on by Johanna Lee
This image was created with the assistance of AI

For decades, pharmaceutical companies have relied on high-throughput screening (HTS) as the first step in the drug discovery process. After an initial screening of thousands of compounds, scientists select a smaller list of candidate drugs that is then used for further downstream testing. A major limitation to HTS, however, is the need to synthesize all compounds used in the screen—the compounds need to physically exist to be tested. This significantly limits the number of compounds that can be tested, hindering the discovery of new drugs.

What if we could test compounds even before they are synthesized?

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Decades of Discovery: How the NCI-60 Revolutionized Cancer Drug Screening

Posted on by Kendra Hanslik

The National Cancer Institute’s NCI-60 drug screening panel, comprised of 60 diverse human cancer cell lines, has been a cornerstone in advancing cancer research and drug discovery since its inception in the late 1980s. Developed in response to the need for more predictive and comprehensive preclinical models, the NCI-60 facilitates the screening of thousands of compounds annually, aiming to identify potential anti-cancer drugs across a broad spectrum of human cancers. This article traces the origins, development, and evolution of the NCI-60 panel, highlighting its significant role in advancing our understanding of cancer and therapeutic agents.  

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Discovering Cyclic Peptides with a “One-Pot” Synthesis and Screening Method

Posted on by Jordan Nutting

In the evolving landscape of drug discovery, cyclic peptides represent an exciting opportunity. These compounds offer a unique balance of size and specificity that positions them to bridge the gap between small molecule drugs and larger biologics like antibodies.

However, most cyclic peptides demonstrate low oral bioavailability: they are digested in the stomach before they can enter the bloodstream, or they’re not absorbed into the bloodstream by the gastrointestinal tract and can have little therapeutic effect (1). Biologics face a similar challenge and are administered intravenously rather than with a more convenient pill form.

A 384 well plate next to a collection of pills of different sizes and shapes.


To address the challenge of low oral bioavailability of cyclic peptides, a team from the Ecole Polytechnique Fédérale de Lausanne in Switzerland developed a “one-pot” method to synthesize a diverse library of cyclic peptides, which they then screened for stability, activity and permeability (1). Their method, which was published December 2023 in Nature Chemical Biology, streamlined the process of identifying and optimizing cyclic peptides and marked a substantial improvement from their earlier studies, where the developed cyclic peptides exhibited almost no oral bioavailability (%F). Using this new method, the team successfully developed a cyclic peptide with 18%F oral bioavailability in rats.

This blog covers the details of this study as well as a brief background on cyclic peptides.

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Will Artificial Intelligence (AI) Transform the Future of Life Science Research?

Posted on by Ken Doyle

Artificial intelligence (AI) is not a new technological development. The idea of intelligent machines has been popular for several centuries. The term “artificial intelligence” was coined by John McCarthy for a workshop at Dartmouth College in 1955 (1), and this workshop is considered the birthplace of AI research. Modern AI owes much of its existence to an earlier paper by Alan Turing (2), in which he proposed the famous Turing Test to determine whether a machine could exhibit intelligent behavior equivalent to—or indistinguishable from—that of a human.

The explosive growth in all things AI over the past few years has evoked strong reactions from the general public. At one end of the spectrum, some people fear AI and refuse to use it—even though they may have unwittingly been using a form of AI in their work for years. At the other extreme, advocates embrace all aspects of AI, regardless of potential ethical implications. Finding a middle ground is not always easy, but it’s the best path forward to take advantage of the improvements in efficiency that AI can bring, while still being cautious about widespread adoption. It’s worth noting that AI is a broad, general term that covers a wide range of technologies (see sidebar).

AI personified looking at a dna double helix against an abstract cosmic background
Image generated with Adobe Firefly v.2.

For life science researchers, AI has the potential to address many common challenges; a previous post on this blog discussed how AI can help develop a research proposal. AI can help with everyday tasks like literature searches, lab notebook management, and data analysis. It is already making strides on a larger scale in applications for lab automation, drug discovery and personalized medicine (reviewed in 3–5). Significant medical breakthroughs have resulted from AI-powered research, such as the discovery of novel antibiotic classes (6) and assessment of atherosclerotic plaques (7). A few examples of AI-driven tools and platforms covering various aspects of life science research are listed here.

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Insights from our Second Annual Targeted Protein Degradation Symposium

Posted on by Jordan Nutting

In the opening remarks of our second annual Targeted Protein Degradation Symposium, Tom Livelli, VP of Life Sciences Products & Services at Promega, posed a question to the attendees: “What do you want to be able to do today that you can’t?” This aspirational question set the tone for an event where building connections to advance the study and application of proximity-induced degradation took center stage.

More than 90 attendees from academia and industry gathered September 20–21 for the two-day symposium, which was hosted in our inspirational Kornberg Center—the R&D heart of Promega. Through engaging talks, a poster session, “Learn n’ Burn” challenges and social gatherings, participants had the opportunity to reinforce existing collaborations and to connect with others who are making an impact in the field of targeted protein degradation.

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Genome-Wide CRISPR Screening: Putting Death on Hold

Posted on by Ken Doyle

We share this planet with approximately 8.7 million species of plants and animals. Within such a diverse environment, it’s only natural that many complex relationships have developed among different species. Some relationships are mutually beneficial, some are parasitic—and some are lethal.

Genome wide - crisper screening to help with toxic compounds to humans

Natural toxins and venoms are biologically active compounds produced by normal metabolic processes in an organism but are harmful to other organisms. Typically, toxins are encountered passively or ingested by the affected organisms, and have a specific mode of action and binding site within a cell. In contrast, venoms are introduced directly into the victim through a specialized delivery mechanism, and they may consist of a mixture of compounds that affect a range of cell types and tissues (1). Both types of poisons are produced for predation, defense, or to offer a competitive advantage (1).

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