Related Experiment Video
Updated: Feb 6, 2026

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions
Published on: June 16, 2014
A Computational Comparison of Soft Landing of α-Helical vs Globular Peptides
Danielle Frederickson1, Meghan McDonough1, George L Barnes1
1Department of Chemistry and Biochemistry , Siena College , 515 Loudon Road , Loudonville , New York 12211 , United States.
Abstract:
The effect of secondary structure on the soft landing process is investigated through direct dynamics simulations of AcA7K and AcKA7 colliding with a fluorinated, organic self-assembled monolayer (FSAM) surface. The α-helical (AcA7K) and globular (AcKA7) peptides each exhibited a similar probability of soft landing with normal incidence at all collision energies considered. Rapid conformational changes were quantified through the calculation of the time dependent, conformational entropy production that took place during the collision events, which is consistent with the prior structural measurements made by Laskin and co-workers on these systems. AcA7K produces more entropy during the collisions than AcKA7.
More Related Videos
Related Concept Videos
Globular and Fibrous Proteins
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Globular and Fibrous Proteins
The Colonization of Land
Globular Proteins
Globular proteins serve many important physiological functions, such as acting as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be soluble in the aqueous...
Peptide Bonds
The Sense of Self: Reflected Self-Appraisal and Social Comparison

