Investigating the Stability of RADA16 Peptide Nanofibers Using CD Spectra

  • Hadis Zarei
  • Asieh AramvashEmail author
  • Mansooreh Sadat Seyedkarimi


RADA 16-I is a synthetic amphiphilic peptide which self-assembles into nanofibers and scaffolds in favor of cell growth, hemostasis and tissue engineering. However, it is still unclear in which conditions the peptide maintains its stability and structural consistency in aqueous solutions during storage time. This study investigates dynamic behavior of RADA 16-I using circular dichroism, so as to monitor changes in conformation of the peptides dispersed in water (pH 5) as well as 0.003 M (pH 4) and 0.02 M (pH 3) acetic acid solutions for various incubation times (0.5, 60 and 120 days), concentrations (0.1, 0.3 and 0.5%) and temperatures (4 and 25 °C). The results showed that the peptides exhibit a predominantly helical structure immediately after making their solutions. However, it was seen that, when exposed to solutions with pH 3 and 4, the peptides started to lose the helical structure, with increased amounts of aggregation at these two acidic pH values; this was attributed to increased hydrophobicity. The stable RADA 16-I peptides were identified at pH 5, 0.1% solution and 4 °C, with their secondary structure remained mostly unchanged during the 120-day test period. Furthermore, statistical analysis showed that, the concentration had little effect while pH and temperature had significant effects on the peptide stability, while acidic pH enhanced aggregation. These results may serve as a scientific basis for the processing and application of peptide.


Aggregation Biomaterial Peptide amphiphile Self-assembly Stabiliy 



The authors would like to thank the research council of Malek-Ashtar University of Technology for the financial support of this investigation.

Compliance with Ethical Standards

Conflict of interest

The authors declare that this article content has no conflicts of interest.

Ethical Approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Informed Consent

The article does not contain any studies in patients by any of the authors.


  1. Aggeli A, Bell M, Carrick LM, Fishwick CW, Harding R, Mawer PJ, Radford SE, Strong AE, Boden N (2003) pH as a trigger of peptide β-sheet self-assembly and reversible switching between nematic and isotropic phases. J Am Chem Soc 125:9619–9628CrossRefGoogle Scholar
  2. Aramvash A, Seyedkarimi MS (2015) All-atom molecular dynamics study of four RADA 16-I peptides: the effects of salts on cluster formation. J Cluster Sci 26:631–643. CrossRefGoogle Scholar
  3. Bagrov D, Gazizova Y, Podgorsky V, Udovichenko I, Danilkovich A, Prusakov K, Klinov D (2016) Morphology and aggregation of RADA-16-I peptide Studied by AFM, NMR and molecular dynamics simulations Biopolymers. 106(1):72–81.
  4. Bellesia G, Shea JE (2009) Effect of β-sheet propensity on peptide aggregation. J Chem Phys 130:145103. CrossRefGoogle Scholar
  5. Bello J, Bello HR, Granados E (1982) Conformation and aggregation of melittin: dependence on pH and concentration. Biochemistry 21:461–465CrossRefGoogle Scholar
  6. Chen P (2005) Self-assembly of ionic-complementary peptides: a physicochemical viewpoint. Colloids Surf A 261 (1–3):3–24. CrossRefGoogle Scholar
  7. Cormier AR, Pang X, Zimmerman MI, Zhou HX, Paravastu AK (2013) Molecular structure of RADA16-I designer self-assembling peptide nanofibers. ACS Nano 7(9):7562–7572CrossRefGoogle Scholar
  8. Creighton TH (1993) Proteins: structures and molecular properties. W.H. Freeman, San FranciscoGoogle Scholar
  9. Fung SY, Keyes C, Duhamel J, Chen P (2003) Concentration effect on the aggregation of a self-assembling oligopeptide. Biophys J 85(1):537–548. CrossRefGoogle Scholar
  10. Greenfield NJ (1996) Methods to estimate the conformation of proteins and polypeptides from circular dichroism data. Anal Biochem 235:1–10. 2.CrossRefGoogle Scholar
  11. Johnson WC (1988) Secondary structure of proteins through circular dichroism spectroscopy. Annu Rev Biophys Biophys Chem 17:145–166. CrossRefGoogle Scholar
  12. Luo Z, Åkerman B, Zhang S, Nordén B (2010) Structures of self-assembled amphiphilic peptide-heterodimers: effects of concentration, pH, temperature and ionic strength. Soft Matter 6:2260–2270CrossRefGoogle Scholar
  13. Ramalingam K, Aimoto S, Bello J (1992) Conformational studies of anionic melittin analogues: effect of peptide concentration, pH, ionic strength, and temperature-models for protein folding and halophilic proteins. Biopolymers 32(8):981–992CrossRefGoogle Scholar
  14. Smith RM, David DE (1998) The pH-rate profile for the hydrolysis of a peptide bond. J Am Chem Soc 120(35):8910–8913CrossRefGoogle Scholar
  15. Sun Y, Li W, Wu X, Zhang N, Zhang Y, Ouyang S, Song X, Fang X, Seeram R, Xue W, He L, Wu W (2016) Functional self-assembling peptide nanofiber hydrogels designed for nerve degeneration. ACS Appl Mater Interfaces 8(3):2348–2359. CrossRefGoogle Scholar
  16. Talley K, Alexov K (2010) On the pH-optimum of activity and stability of protein. Proteins 78(12):2699–2706Google Scholar
  17. Yang Y, Khoe U, Zhang S (2009) Designer self-assembling peptide nanomaterials. Nano Today 4:193–210. CrossRefGoogle Scholar
  18. Ye Z, Zhang H, Luo H, Wang S, Zhou Q, DU X, Tang C, Chen L, Liu J, Shi YK, Zhang EY, Ellis-Behnke R, Zhao X (2008) Temperature and pH effects on biophysical and morphological properties of self-assembling peptide RADA16-I. J Pept Sci 14(2):152–162. CrossRefGoogle Scholar
  19. Yeaman MR, Yount NY (2003) Mechanism of antimicrobial peptide action and resistance. Pharmacol Rev 55:27–55CrossRefGoogle Scholar
  20. Zhang S, Marini DM, Hwang W, Santoso S (2002) Design of nanostructured biological materials through self-assembly of peptides andproteins. Curr Opin Chem Biol 6:865–871CrossRefGoogle Scholar
  21. Zhang H, Luo H, Zhao X (2010) Mechanistic study of self-assembling peptide RADA16-I in formation of nanofibers and hydrogels. J Nanotechnol Eng Med 1(1):011007–011006. CrossRefGoogle Scholar
  22. Zhao X, Zhang S (2007) Designer self-assembling peptide materials. Macromol Biosci 7:13–22. CrossRefGoogle Scholar
  23. Zhao X, Pan F, Xu H, Yaseen M, Shan H, Hauser CA, Zhang S, Lu JR (2010) Molecular self-assembly and applications of designer peptide amphiphiles. Chem Soc Rev 39:3480–3498. CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Hadis Zarei
    • 1
  • Asieh Aramvash
    • 1
    Email author
  • Mansooreh Sadat Seyedkarimi
    • 1
  1. 1.Department of Bioscience and BiotechnologyMalek-Ashtar University of TechnologyTehranIran

Personalised recommendations