Daptomycin peptide

Daptomycin peptide

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

Batch to batch variation of the purity

WNDTGKDADGSEY

Trp-Asn-Asp-Thr-Gly-Lys-Asp-Ala-Asp-Gly-Ser-Glu-Tyr

13

95.4%

Synthetic

Powder

An FDA approved antibiotic. Warning: the sequence is a close mimic of the natural counterpart. The natural form is cyclic due to the ester bond between the hydroxyl of T4 and the carboxyl of kynurenine-13 (represented by Y here). The N-terminus is lipidated with n-decanoyl fatty acid chain. Other nonstandard amino acids include ornithine-6 (represented with K), (2S,3R)-3-methyl-glutamic acid-12 (represented with E), and three D-amino acids at positions N2, A8, and S11. Active against various Gram-positive bacteria such as S. aureus. This is another anionic peptide that is distinct from many of the cationic AMPs. Its activity requires the presence of Ca2+ (calcium) that causes the aggregation of the peptide. Resistance to this peptide antibiotic was observed one year after its introduction in 2003. Daptomycin was found in Streptomyces roseosporus NRRL11379.

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

• Eliopoulos GM, Willey S, Reiszner E, Spitzer PG, Caputo G, Moellering RC. In vitro and in vivo activity of LY 146032, a new cyclic lipopeptide antibiotic. Antimicrob Agents Chemother. 1986;30(4):532-5.

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.