CALP1 peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

CALP1 is an octameric peptide designed to interact with EF-hand motifs, which are calcium-binding domains found in proteins such as calmodulin (CaM). The peptide exhibits a complementary surface contour to an eight-amino-acid stretch within the loop sequence of EF hands, enabling specific binding. CALP1 has been shown to bind the EF hands of CaM, forming a peptide/CaM complex that can modulate calcium-sensitive processes. The peptide is capable of entering cells and influencing calcium-permeable channels, such as glutamate receptor channels and nonselective cation channels, through direct or indirect interactions involving CaM.

CALP1 demonstrates the ability to block calcium influx by targeting the regulatory mechanisms of ion channels rather than their pore regions or ligand-binding sites. Single-channel analysis reveals that CALP1 modulates channel activity by altering open probability and conductance. Its interaction with calcium-sensing domains highlights its role as a novel calcium channel blocker, distinct from traditional inhibitors. The peptide's effects are reversible, indicating a non-accumulative and targeted mechanism of action.

• Manion MK, Su Z, Villain M, Blalock JE. A new type of Ca(2+) channel blocker that targets Ca(2+) sensors and prevents Ca(2+)-mediated apoptosis. FASEB J. 2000 Jul;14(10):1297-306. doi: 10.1096/fj.14.10.1297. PMID: 10877822.

Trifluoroacetic acid (TFA) has a significant impact on peptides due to its role in the peptide synthesis process.

TFA is essential for the protonation of peptides that lack basic amino acids such as Arginine (Arg), Histidine (His), and Lysine (Lys), or ones that have blocked N-termini. As a result, peptides often contain TFA salts in the final product.

TFA residues, when present in custom peptides, can cause unpredictable fluctuations in experimental data. At a nanomolar (nM) level, TFA can influence cell experiments, hindering cell growth at low concentrations (as low as 10 nM) and promoting it at higher doses (0.5–7.0 mM). It can also serve as an allosteric regulator on the GlyR of glycine receptors, thereby increasing receptor activity at lower glycine concentrations.

In an in vivo setting, TFA can trifluoroacetylate amino groups in proteins and phospholipids, inducing potentially unwanted antibody responses. Moreover, TFA can impact structure studies as it affects spectrum absorption.