Optimer ligand

Key takeaways

Optimer ligand belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Optimer ligand to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Optimer ligand from memory before moving on to harder problems.

Reference excerpt

Optimer ligands are short synthetic oligonucleotide molecules composed of DNA or RNA that bind to a specific target molecule. They are engineered to bind their target molecules with affinity typically in the low nanomolar range. Optimers can be used as antibody mimetics in a range of applications, and have been optimized to increase their stability, reduce their molecular weight, and offer increased scalability and consistency in manufacture compared to standard aptamer molecules.

Structure Optimer ligands are composed of single-stranded DNA or RNA polymers. These nucleic acid molecules can exhibit cognate base-pairing to produce sections of double-stranded DNA or RNA within the Optimer molecules. Optimer ligands form secondary and tertiary structures with compatible internal base-pairing at specific portions of the ligand where possible according to the specific sequence. As not all of the bases in the Optimer sequence will be compatible for internal double-stranded pairing, single-stranded loop and bulge regions will remain in the secondary and tertiary structures, where hydrogen bond acceptor and donor groups are exposed and available to interact with the selected target for target engagement and target binding. The Optimer library that is screened for specific binders consists of 1014 sequences that will form different variable sequence-dependent structures. The wide diversity in this library enables target binding to a range of different molecules. Optimer molecules can bind crevices and exposed epitopes on protein and cellular targets and can wrap around small molecule targets. This enables an increased target range compared to traditional antibody technology that has limitations in accurately binding small molecule targets. As Optimer technology stems from aptamers, Optimer ligands have the ability to operate as reversible structural switches, changing their structure when binding their target molecule. This reversible target binding and release means the Optimer ligand is regenerated and can be used for real-time continuous sensing for biological monitoring.

Development Developed as a next generation aptamer technology, Optimer ligands were produced to improve the performance, manufacturability, and commercialisation of aptamers. Optimer ligands are selected via an automated, high throughput in vitro screening process. 3 distinct discovery platforms are integrated into the Optimer platform for optimized discovery according to target type. Starting from a diverse library of potential nucleic acid binders, the Optimer library is refined and enriched for sequences that have the required binding characteristics including affinity, specificity, cross reactivity, and buffer compatibility. The enriched Optimer population is subsequently screened to identify the best performing Optimer ligand sequence. Following selection of the appropriate sequence the identified Optimer undergoes a process to determine the minimum oligonucleotide fragment within this sequence that possesses the correct target-binding characteristics. The Optimer is trimmed to contain only this sequence, removing additional free non-target binding nucleotide bases. This reduces the molecular weight of the Optimer from 29 kDa to 5 kDa and increases the stability of the molecule through a reduction in entropy, as additional motion of the free nucleotides is removed.

Optimer discovery platform Three Optimer discovery platforms are used for Optimer selection. Each of the platforms is optimized to select Optimers according to the target type:

Small molecule targets Protein targets Cells and tissues Multiple rounds of selection and counter-selection are performed as part of each Optimer discovery process. Each discovery process can be adapted to include specific target, assay and buffer conditions to improve Optimer selection.

Production Optimer ligands are produced via solid-phase synthesis. Solid-phase chemical synthesis was invented in the 1960s by Robert Bruce Merrifield, for which he was awarded the Nobel Prize for Chemistry in 1984. Solid-phase synthesis is carried out on a solid support held between filters, in columns that enable all reagents and solvents to pass through freely. Solid-phase synthesis has a number of advantages over cell-based manufacturing that is typically used for protein affinity reagents, such as antibodies:

large excesses of solution-phase reagents can be used to drive reactions quickly to completion impurities and excess reagents are washed away and minimal purification is required following production the process is amenable to automation on computer-controlled solid-phase synthesizers simple, automated chemical processes make production scalable with high batch-to-batch consistency no competition for cell-based manufacturing space for cost efficient manufacturing capacity

Properties Optimer ligands are small, synthetic molecules. The sequence of each isolated Optimer is known ensuring security of supply. These synthetic antibodies are stable for years at room temperature with no loss in performance and do not require cold chain logistics. Additionally they are non-immunogenic.

Applications Optimer technology has been developed and commercialised by Aptamer Group, which is developing these affinity reagents as biotherapeutics and diagnostic tools.

Therapeutics Optimer ligands are being investigated for use in drug discovery and development. The small size and stability profile of Optimer ligands combined with the lack of immunogenicity confer good drug-like properties on these molecules. In a similar manner to antibody therapeutics, Optimer therapeutics can be used as direct agonists or antagonists for the development of novel therapeutic moieties. Additionally, Optimers can be used as conjugates for the targeted delivery of a range of drug cargo, such as chemotherapeutics, gene silencing therapeutics, and radionuclides. Optimer therapeutics are being developed in partnership with Cancer Research UK that can selectively target a key gene fault for the treatment of Chronic Myelomonocytic Leukaemia (CMML) and other myeloid malignancies. Optimer conjugate therapies are being developed in partnership with AstraZeneca and PinotBio.

… excerpt ends here. Continue reading the full article.

Illustrations

Optimer ligand: Optimer structure with non target binding groups removed for improved Optimer performance and manufacturability. — Optimer structure with non target binding groups removed for improved Optimer performance and manufacturability.

Worked examples

Example 1 — a first encounter with Optimer ligand

Start with the simplest possible case. Write down what Optimer ligand claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Optimer ligand before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Optimer ligand ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Optimer ligand

In research: Optimer ligand appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Optimer ligand in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Optimer ligand is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nucleic acids, so understanding it makes those chapters shorter.
In everyday life: Look for Optimer ligand outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Optimer ligand in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Optimer ligand means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Optimer ligand out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Optimer ligand in simple terms?

Optimer ligands are short synthetic oligonucleotide molecules composed of DNA or RNA that bind to a specific target molecule. They are engineered to bind their target molecules with affinity typically in the low nanomolar range.

Why does Optimer ligand matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Optimer ligand?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Optimer ligand.