Size-dependent affinity of glycine and its short oligomers to pyrite surface: a model for prebiotic accumulation of amino acid oligomers on a mineral surface

Rehana Afrin, Narangerel Ganbaatar, Masashi Aono, H. James Cleaves, Taka Aki Yano, Masahiko Hara

Research output: Contribution to journalArticle


The interaction strength of progressively longer oligomers of glycine, (Gly), di-Gly, tri-Gly, and penta-Gly, with a natural pyrite surface was directly measured using the force mode of an atomic force microscope (AFM). In recent years, selective activation of abiotically formed amino acids on mineral surfaces, especially that of pyrite, has been proposed as an important step in many origins of life scenarios. To investigate such notions, we used AFM-based force measurements to probe possible non-covalent interactions between pyrite and amino acids, starting from the simplest amino acid, Gly. Although Gly itself interacted with the pyrite surface only weakly, progressively larger unbinding forces and binding frequencies were obtained using oligomers from di-Gly to penta-Gly. In addition to an expected increase of the configurational entropy and size-dependent van der Waals force, the increasing number of polar peptide bonds, among others, may be responsible for this observation. The effect of chain length was also investigated by performing similar experiments usingL-lysine vs. poly-L-lysine (PLL), andL-glutamic acid vs. poly-L-glutamic acid. The results suggest that longer oligomers/polymers of amino acids can be preferentially adsorbed on pyrite surfaces.

Original languageEnglish
Article number365
JournalInternational Journal of Molecular Sciences
Issue number2
Publication statusPublished - 2018 Feb 1



  • Atomic force microscopy
  • Glycine
  • Mineral surface
  • Oligo-glycines
  • Origins of life
  • Peptides
  • Pyrite
  • Single molecule interaction
  • Unbinding force measurements

ASJC Scopus subject areas

  • Catalysis
  • Molecular Biology
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

Cite this