Biotin-LC-Kemptide is a synthetic, biotinylated peptide substrate specifically designed for protein kinase A (PKA) activity assays and related phosphorylation research. It consists of the canonical Kemptide sequence (Leu-Arg-Arg-Ala-Ser-Leu-Gly, LRRASLG) labeled at the N-terminus with a biotin moiety linked via a 6-aminocaproic acid (LC, long chain) spacer, which minimizes steric hindrance and preserves substrate recognition by PKA.
Full Name: Biotin-LC-Leu-Arg-Arg-Ala-Ser-Leu-Gly (Biotin-LC-LRRASLG)
Molecular Formula: C₄₈H₈₆N₁₆O₁₂S (free base)
Molecular Weight: 1111.39 (free base)
Key Features & Applications
1. PKA Substrate Specificity: The central Ser residue serves as the exclusive phosphorylation site for PKA, enabling quantitative measurement of kinase activity through phosphate incorporation or antibody-based detection.
2. Biotin Affinity Tag: The biotin-LC modification allows efficient capture, purification, or immobilization of the phosphorylated peptide via streptavidin/avidin matrices, supporting high-throughput screening and pull-down assays.
3. Research Applications: Widely used in PKA activity quantification, kinase inhibitor screening, phosphorylation kinetics studies, and protein-protein interaction analysis involving PKA signaling pathways.