Biotin-LC-Kemptide is a spacer-containing biotinylated derivative of the classic PKA substrate Kemptide. Its structure combines Biotin-LC with the Leu-Arg-Arg-Ala-Ser-Leu-Gly (LRRASLG) substrate sequence.

The long-chain spacer increases the physical separation between the biotin affinity tag and the kinase substrate region, making this construct useful in assay formats that involve streptavidin-coated surfaces or capture reagents.

Product Information

Why Use an LC Spacer?

In direct Biotin-Kemptide, the affinity tag is positioned immediately adjacent to the peptide sequence. Biotin-LC-Kemptide introduces additional spacing between these functional regions.

This separation can improve accessibility of the biotin group during interaction with streptavidin and can reduce steric constraints created when a short peptide is immobilized close to a solid surface.

The magnitude of any spacer effect depends on the assay architecture. We recommend evaluating direct and spacer-linked constructs experimentally when surface capture, enzyme kinetics or detection efficiency is important.

Kinase and Affinity Assay Applications

The LRRASLG segment provides the serine-containing substrate sequence for PKA-dependent phosphorylation, while Biotin-LC supports subsequent capture or immobilization.

Potential applications include streptavidin plate assays, phosphopeptide detection, kinase screening and development of non-radioactive phosphorylation workflows.

Researchers who do not require a spacer can compare this construct with Biotin-Kemptide.

Choosing Between Kemptide Formats

Unmodified Kemptide is appropriate when a minimal soluble PKA substrate is preferred. Direct Biotin-Kemptide adds an affinity handle with minimal additional linker length, while Biotin-LC-Kemptide provides more physical separation between the peptide and streptavidin-binding group.

For assay development, we recommend selecting the construct according to the detection platform rather than treating the three molecular forms as interchangeable.

Frequently Asked Questions

What does LC mean in Biotin-LC-Kemptide?

LC indicates a long-chain spacer positioned between biotin and the Kemptide substrate sequence.

Does the LC spacer change the Kemptide phosphorylation site?

No. The LRRASLG core sequence is retained and Ser5 remains the principal phosphoacceptor within the Kemptide region.

Can different spacer lengths be prepared?

Alternative linker lengths, affinity tags and labeled Kemptide designs can be evaluated through Chemical Peptide Synthesis.

Research Use Only.