Stapled Peptide & Constrained Peptide Design

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Overview

Stapling locks a peptide into the helical conformation it must adopt to bind, paying the entropic cost once during synthesis rather than repeatedly during binding. Done well, it improves affinity, protease resistance and sometimes cell entry. Done carelessly, it abolishes binding by fixing the wrong geometry. We identify which positions can carry a staple without disturbing the binding face, design the crosslink chemistry and geometry, and model the constrained peptide in complex with the target.

Schematic: substitutions are scored at every position for stability and function, with catalytic and binding residues protected from redesign.

Key Advantages

Staple Positions Screened Systematically

All i,i+3, i,i+4 and i,i+7 options are evaluated for geometric feasibility and for whether they sit on the non-binding face, rather than choosing by convention.

Helicity Predicted And Verified

Helical propensity is assessed before and after constraint, and simulation is used to confirm that the staple actually stabilises the intended conformation.

Binding Face Protected

Designs explicitly avoid placing crosslinks on residues that contact the target, which is the most common reason stapled peptides lose activity.

Alternative Constraints Compared

Hydrocarbon stapling, lactam bridges, disulfides and other crosslinks are compared for feasibility and stability in your specific sequence context.

Where This Service Is Used

Stabilising a helical peptide that binds a protein–protein interface

Improving protease resistance and half-life of a helical lead

Attempting intracellular delivery of a peptide inhibitor

Rescuing a peptide with good affinity but poor conformational stability

Designing constrained analogues of a natural helical ligand

Methods and Techniques Applied

Structural analysis of the peptide–target complex and identification of the binding face

Helical propensity analysis across the sequence, with and without constraint

Systematic staple position scanning across spacing options with geometric feasibility checking

Crosslink chemistry selection and modelling of the constrained backbone

Molecular dynamics of the stapled peptide alone and in complex to verify conformational stabilisation

Property assessment covering solubility, aggregation, hydrophobicity and permeability risk

What We Need From You

Peptide sequence and, where available, the structure of the complex with the target

Known SAR identifying which residues are essential for binding

The objective: affinity, stability, cell penetration or a combination

Synthesis capability, since stapling chemistry imposes real constraints

What You Receive

Designed stapled peptides with staple position, chemistry and stereochemistry specified

Complex models with the constrained peptide bound to the target

Helicity and stability analysis comparing constrained and unconstrained forms

Property predictions including the hydrophobicity increase that stapling usually brings

Prioritised synthesis and testing plan across the design set

What We Compute and Report

Helical propensity across the sequence, before and after constraint

Geometric feasibility for every staple position and spacing considered

Complex models confirming the constraint does not occlude the binding face

Simulation-based verification that the staple stabilises the intended conformation

Hydrophobicity and aggregation risk change introduced by the crosslink

Interpretation and Limitations

Computational predictions prioritise hypotheses; they do not independently establish binding, biological activity, therapeutic efficacy, safety or clinical validity. Performance depends on input quality, target class, the structural evidence available and the applicability domain of the selected methods. Scores used for ranking are comparative devices and should not be read as measured quantities. All deliverables are for research use only and are not intended for diagnostic or therapeutic use.

Specifications

Item	Specification	Notes
Peptide length	8–35 residues	Helical segments are the primary target
Designs delivered	10–40 variants	Across staple positions and chemistries
Typical turnaround	4–7 weeks	Including simulation verification
Constraints	Hydrocarbon, lactam, disulfide	Compared for the specific sequence

Service Workflow

Step 01

Scientific Consultation

We discuss the objective, the decision it supports and the data you hold. Nothing is quoted before we understand what the result has to answer.

Step 02

Feasibility Review

We check that the data, target class and available structural evidence can support the proposed approach, and say plainly where they cannot.

Step 03

Technical Proposal

Scope, methods, deliverables, timeline and price are confirmed in writing, together with the limitations we expect to report.

Step 04

Computation and QC

The analysis runs on pinned tool versions in a containerised environment, with quality checkpoints and method comparison where that is informative.

Step 05

Report and Follow-Up

You receive the ranked results, the documented methods, the limitations and a proposed validation plan, plus support in interpreting them.

Is This the Right Service for You?

Choose this service when

The bioactive conformation is helical and the free peptide is disordered

Affinity could be improved by paying the entropic cost during synthesis

Previous stapling attempts abolished activity and the cause is unknown

Consider another service when

The peptide is not helical

Cyclic Peptide Design

A smaller, more drug-like molecule is acceptable

De Novo Small Molecule Design

What Goes Wrong, and How We Handle It

The failure modes that produce confident-looking results which do not survive the next experiment. Each one is designed against rather than discovered afterwards.

The binding face is identified from the complex first, and crosslink positions are restricted to the opposite surface.

Case Studies

The situation

Three stapled analogues of an active helical peptide showed no measurable binding.

What the work involved

The complex was modelled, contact residues were mapped, and the existing staple positions were checked against them; alternative i,i+4 and i,i+7 placements were then scanned on the non-binding face.

What came back

All three original staples sat on contact residues. Fourteen redesigned analogues were delivered on the opposite face, with predicted helicity gain and the hydrophobicity change quantified for each.

Illustrative of the shape this work takes. Details are generalised, no client or target is identified, and scope and outcome vary with the system in question.

Questions We Are Asked Before Scoping

Note: ICDMO delivers computational (in silico) services. Results prioritise hypotheses for testing; they do not by themselves establish binding, biological activity, efficacy or safety. All deliverables are for research use only and are not intended for diagnostic or therapeutic use. Downstream experimental work is scoped separately and executed through qualified partners.

Get in Touch
about Stapled Peptide & Constrained Peptide Design

Tell us about the target, the data you hold and the decision the result needs to support. A scientist reviews every enquiry and replies within one business day.

Feasibility reviewed before any scope or price is fixed

Methods, parameters, confidence and limitations in every report

Confidentiality agreement available before data is shared