Name: Cathepsin D and E FRET Substrate
Brand: Molecular Depot
SKU: B2011297
Price: 595.00 USD
Availability: InStock

<h2>What are synthetic peptides in this category?</h2>
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Peptides in this category are synthetic, short-chain amino acid sequences, available as pre-made catalog products or custom-synthesized to a specific sequence, used most commonly as antigens for raising custom antibodies, as blocking peptides to confirm an antibody's specificity, and as general research tools for studying a specific protein domain or epitope. Because a short peptide is often too small to provoke a strong immune response on its own, peptide antigens intended for immunization are frequently conjugated to a larger carrier protein, a service covered in the sibling Peptide Conjugates category.
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<h2 dir="ltr">What you will find:</h2>
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Functional Receptor Ligands: Purified short-chain sequences calibrated to modulate specific cellular pathways without introducing non-specific cross-reactivity.
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Targeted Antigenic Determinants: Distinct peptide fragments structured to validate structural recognition assays and trigger predictable antibody responses.
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Enzyme Substrate Chains: High-stability polypeptide sequences optimized for kinetic profiling, cleavage analysis, and screening potential biochemical inhibitors.
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<h2>How to choose synthetic peptides</h2>
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Design your peptide sequence around the intended epitope
For antibody development, peptide sequence and length should target a region of the full protein likely to be antigenic and accessible in the native or denatured protein context, depending on your intended downstream application.
Decide whether your peptide needs a terminal cysteine for conjugation
A peptide intended for later conjugation to a carrier protein via maleimide chemistry typically needs an added cysteine residue at either the N- or C-terminus, and whichever terminus carries the natural epitope should generally remain free to preserve antigenicity.
Confirm peptide purity matches your application's sensitivity
Higher-purity peptides cost more but reduce the risk that a contaminating sequence variant interferes with antibody specificity or a sensitive binding assay, making purity level a worthwhile checkbox to confirm against your application's tolerance for impurities.
Consider a blocking peptide alongside your primary antibody
A blocking peptide, corresponding to the same sequence used to generate a primary antibody, can be used to pre-absorb that antibody and confirm that observed signal in an assay is genuinely specific to the intended epitope rather than background.
Plan for appropriate storage based on peptide modification
Modified peptides, particularly those with oxidation-sensitive residues like cysteine or methionine, may need different storage conditions than simple, unmodified peptides to avoid degradation before use.
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<h2>Specifications context</h2>
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Peptide antigens used to generate custom antisera are commonly synthesized with an added cysteine at either the N- or C-terminus specifically to enable later conjugation to a carrier protein through thiol-maleimide chemistry, a widely used, highly specific coupling method for attaching a peptide to a larger immunogenic protein. As of 2026, branched multi-peptide constructs synthesized on a polylysine core continue to be used as an alternative to carrier protein conjugation for some peptide antigens, since their larger overall molecular weight can make them sufficiently immunogenic without a separate conjugation step.
<a href="https://mbpinc.net/contact-us">Contact the helpful team</a> at MBP today to request a quote.

Peptides

Molecular Depot

Key Specifications

Cathepsin D and E FRET Substrate

Cathepsin D and E FRET Substrate by Molecular Depot is a fluorogenic substrate for the aspartic proteases cathepsin D and cathepsin E. Cleavage of the peptide separates the fluorophore from its quencher. It is used to measure cathepsin D and E activity in purified enzyme, lysosome and cell lysate assays and to screen inhibitors. Each unit contains 1 mg. MBP supplies Molecular Depot protein reagents to research labs in the United States, Canada and worldwide.