Hel 13-5 

Hel 13-5 is a monomeric, lipophilic, basic amphipathic α-helical synthetic peptide composed of 18 amino acid residues. Hel 13-5 is designed as a substitute for proteins in artificial pulmonary surfactants, and it mimics the interaction between the N-terminal fragment of human pulmonary surfactant protein B and lipids. Hel 13-5 can bind to phospholipids for the development of pulmonary surfactant model systems. Hel 13-5 can be used in studies related to respiratory distress syndrome^[1][2].

Hel 13-5 (10 μM) forms an α-helical structure in aqueous buffer and retains α-helical structural characteristics in the presence of neutral, acidic, and soy lecithin liposomes at 10 μM concentration^[1].
Hel 13-5 (20 μM) exhibits near-complete hemolytic activity at an approximate concentration of 20 μM, with activity increasing in a concentration-dependent manner; this activity profile is shared with its derivative Hel 13-5D3^[1].
Hel 13-5 (0.01-0.025 molar fraction) alters the phase domain morphology of DPPG and DPPC/DPPG (4:1) Langmuir monolayers, reducing LC domain size in both systems, with more pronounced dispersion in DPPG/Hel 13-5 due to specific electrostatic interactions^[2].
Hel 13-5 (0.01-0.1 molar fraction) induces distinct phase behavior in DPPG Langmuir monolayers (forming two independent LC domain populations at X_Hel 13-5 = 0.01-0.05) due to specific electrostatic interactions, while only reducing LC domain size in DPPC/DPPG (4:1) monolayers due to dominant DPPC-DPPG miscibility^[2].
Hel 13-5 (0.1 molar fraction) forms larger, stabilized squeezed-out aggregates in DPPG LB films (retaining structure down to 35 mN m⁻¹ during expansion) due to specific electrostatic interactions, while forming smaller, rapidly respreading aggregates in DPPC/DPPG (4:1) and DPPC films^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

The Hel 13-5 (2.5% weight fraction in Murosurf SLP mixture)-containing Murosurf SLP mixture restores pulmonary compliance in surfactant-deficient Wistar rats, but shows lower efficacy than the D-amino acid-modified Hel 13-5D3-containing mixture and Surfacten®^[1].
The Hel 13-5 (0.1 mL (20 mg/mL); respiratory tract)-containing Murosurf SLP mixture suppresses egg white albumin-induced pulmonary resistance elevation and reduces allergic inflammatory cell infiltration in Brown Norway rat asthma models^[1].
Pulmonary surfactant preparations containing Hel 13-5 provide improvement to lung function and activity in surfactant-deficient rat^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

2202.98

C₁₁₃H₂₀₄N₂₄O₁₉

177942-21-1

Solid

White to off-white

Lys-Leu-Leu-Lys-Leu-Leu-Leu-Lys-Leu-Trp-Leu-Lys-Leu-Leu-Lys-Leu-Leu-Leu

KLLKLLLKLWLKLLKLLL

Room temperature in continental US; may vary elsewhere.

Sealed storage, away from moisture

*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)

• [1]. Nakamura Y, et al. Improvement of pulmonary surfactant activity by introducing D-amino acids into highly hydrophobic amphiphilic α-peptide Hel 13-5. Biochim Biophys Acta. 2014;1838(8):2046-2052.

  [2]. Nakahara H, et al. Pulmonary surfactant model systems catch the specific interaction of an amphiphilic peptide with anionic phospholipid. Biophys J. 2009;96(4):1415-1429.  [Content Brief]