SPA4 peptide

SPA4 peptide

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

Batch to batch variation of the purity

H-GDFRYSDGTPVNYTNWYRGE-OH

H-Gly-Asp-Phe-Arg-Tyr-Ser-Asp-Gly-Thr-Pro-Val-Asn-Tyr-Thr-Asn-Trp-Tyr-Arg-Gly-Glu-OH

20

95.68%

C₁₀₇H₁₄₅N₂₉O₃₅

2397.46

Synthetic

Powder

SPA4 peptide is a TLR4 interacting peptide identified from the interface of the surfactant protein-A (SP-A) –TLR4 complex. The interaction between SP-A and TLR4 is important for host defence and SPA4 peptide binding to the activated TLR4 complex suppresses inflammatory responses, inhibiting mRNA and cellular protein levels of pro-interleukin-1β, caspase activity and release of interleukin-1β, without affecting TLR4-induced uptake, processing, and clearance of ligands and pathogens. SPA4 peptide does not bind to the natural TLR4 ligand, LPS, or gram-negative bacteria directly. Intraperitoneally and intratracheally administered SPA4 peptide reduces inflammation, bacterial burden, and associated lung injury in mouse models of LPS induced lung inflammation and pseudomonas aeruginosa induced lung infection.

Normally, this peptide will be delivered in lyophilized form and should be stored in a freezer at or below -20 °C. For more details, please refer to the manual: Handling and Storage of Synthetic Peptides

• Ramani and Awasthi (2015) Toll-like receptor 4-interacting SPA4 peptide suppresses the NLRP3 inflammasome in response to LPS and ATP stimuli. J Leukoc Biol. 98(6) 1037 PMID: 26254306
• Awasthi et al (2020) Lung and general health effects of Toll-like receptor-4 (TLR4)-interacting SPA4 peptide. BMC Pulm Med. 20(1) 179 PMID: 32576172
• Awasthi et al (2021) Mechanism of Anti-Inflammatory Activity of TLR4-Interacting SPA4 Peptide. Immunohorizons 24 5(8) 659 PMID: 34429343

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.